• Transactions of the Korean hydrogen and new energy society
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• v.12 no.4
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• pp.257-265
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• 2001

Placing a hydrogen conducting, methanol impermeable metallic barrier like palladium (Pd) is a well-known method for preventing methanol crossover through solid polymer electrolyte for direct methanol fuel cells (DMFC). Applying a bias potential between the anode and the barrier can further develop this concept so that the hydrogen transfer rate is enhanced. Since hydrogen diffuses in Pd as atomic form while it moves through nafion electrolyte as ion, it has to be reduced or oxidized whenever it passes the interface formed by Pd and the electrolyte. We performed experiments to measure the hydrogen transport through the Pd membrane placed in Nafion electrolyte of hydrogen/oxygen fuel cell (PEMFC). Applying a bias potential between the hydrogen electrode of the cell and the Pd membrane facilitated the hydrogen passage through the Pd membrane. The results show that the cell current measured with the Pd membrane placed reached almost 40 % the value measured with the cell without Pd membrane. It was found that the current flown through the bias path is only a few percent of the cell current.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.51-65
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• 2005

The insects and Benthic Macro-Invertebrates are very important for index of investigation. This reserch is executed a field investigation with a date analysis of the laboratory under such as above hypothesis and we have grasped the change of the creature according to the season through the executing of field investigation(We executed six times about the insects, seven times about the Benthic Macro-Inbertebrates each expending from Apr. to Oct. 2004). The result of summary in 2004 show that, we have grasped 12 orders 56 familys 116 species on 2001 and 10 orders 42 familys 78 species on 2002 through the investigation. Also we have grasped 13 orders 53 familys 114 species on 2003 and 12 orders 63 familys 121 speceies on 2004 through the investigation. In the case of enthic Macro-Invertebrates, we executed the analysis through the investigation result expending from 2003 to 2004 due to there is no literature investigation record from 2001 to 2002. We have grasped 8 orders 17 familys 24 species on 2003 and 7 orders 11 familys 24 species on Aug. 2004 through the investigation. We executed the analysis about an each condition due to it is difficult to compare the above result simply by the various variable at the investigation. We expect that it become the fundamental reference data to establish a efficient mode of life undo plan after grasped the inhabitation and movement route of creature inside the river through this reserch.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.98-112
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• 2021

This study aimed at measuring students' interaction in distance education through the electronic platform among intermediate school students, by identifying the level of students' interaction in distance education and differences between them, as well as its impact on their motivation to learn. To achieve the aim of the study, two scales were designed for this purpose and were applied to a sample consisting of (268) individuals. The results showed that the level of students' interaction through the e-learning platform was at a high level. The results also showed that there was no statistically significant difference between the mean scores of males and females in the scale of students' interaction through the e-learning platform. There was no statistically significant difference between them in their motivation for distance learning via the online platform. There were also no statistically significant differences related to the grade variable in the level of interaction through the electronic platform and in the motivation to learn, while there was a positive statistically significant effect of interaction through the electronic platform on students' motivation to learn.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.93-103
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• 2022

This study investigated the method of continuous improvement of small-medium company production processes through POSCO's QSS(Quick Six Sigma) activities. QSS is a field operation technique that encompasses the advantages of Six Sigma, TPS(Toyota Production System), TQM (Total Quality Management), and IE(Industrial Engineering). Through this, POSCO not only encourages activities centered on related small and medium-sized partners, etc., but is also expected to contribute to the continuous improvement of the company's own production process through QSS activities. In this study, rather than unconditionally carrying out activities according to the needs of large companies, the research is to help the continuous improvement of the actual production process of small and medium-sized enterprises by effectively applying and spreading QSS activities in consideration of the characteristics and environment of the company. For this purpose, empirical research is conducted on the process improvement activities and QSS activities of company Y, which has less than 100 assembly and production quality and inspection processes among SMEs. The changes in the production process improvement of SMEs through the application of the final QSS were investigated through empirical studies.

• Korean Institute of Interior Design Journal
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• v.26 no.3
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• pp.25-33
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• 2017

The purpose of this study is to analyze the characteristics of interior space in his design hotel through the analysis of Tony Chi 's work and to present the direction of the design direction of the interior space of the design hotel in the future based on the results. The results are summarized as follows. First, the characteristics of the interior space of Tony Chi are divided into visual balance, repetitive rhythm, symbolic emphasis, exaggerated scale, design harmony, and physical borderlessness. Second, the spatial composition through visual balance was consistently shown in all cases, mainly by arranging elements such as furniture and lighting symmetrically. Third, the spatial composition through repetitive rhythm did not show its characteristics at the beginning of the works, but gradually appeared as repetitive rhythm expression using bold pattern. Fourth, Toni Chi constantly expressed the space composition through symbolic emphasis during the planning of the design hotel. Fifth, the exaggerated scale was mainly used to express the architectural detail vertically according to the height of the ceiling to express a grand space and appear in many works. Sixth, Toni Chi consistently expressed the composition of space through the harmony of design of oriental and western cultures, classical and modern designs in all cases. Seventh. In order to provide curiosity induction and aesthetic experience, spatial composition through physical borderlessness was used.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.214-219
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve m (12 m) depth of the reactor pool and cold by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and exit through the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be Quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to study the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, about fourteen kilogram per second (14 kg/s) suppressed the guide tube jet and met the design cooling flow rate in a circular flow tube, and that the fission moly target cooling flow rate met the minimum flow rate to cool the target.

• The Korean Journal of Emergency Medical Services
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• v.16 no.2
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• pp.75-89
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• 2012

Purpose : This research was designed to provide basic data for advanced pre-hospital airway management by comparing the time to ventilation and success rate for tracheal intubation performed with Macintosh laryngoscope and intubating Laryngeal Mask Airway(ILMA) in a manikin. Methods : All participants were novice users among EMT-Paramedic students and were divided into two groups: (1) the group for Macintosh laryngoscope guided tracheal intubation(MLG-TI) (2) the group for ILMA guided tracheal intubation(ILMA-TI). After an introductory lecture and demonstration, each group made an attempt ten tracheal intubation to compare the ventilation time and success rate for tracheal intubation. Results : 1) There was significant difference in the time to ventilation through MLG-TI, the time to first and second ventilation through ILMA-TI of the 10 attempts. 2) The time to first ventilation through ILMA-TI was significantly shorter than that of ventilation through MLG-TI. 3) There was no significant difference between the time to ventilation through MLG-TI and the time to second ventilation through ILMA-TI. 4) The success rates of ILMA-TI were significantly higher than those of MLG-TI. Conclusion : ILMA-TI can be an alternative method for MLG-TI in advanced pre-hospital airway management.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.53-60
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• 2009

For the case of the facilities using utilities such as cooling water and steam, risk of the facilities is zero because the consequence of failure (COF) through equipment damage area is zero. Therefore, to improve the estimation method of the risk by COF through equipment damage area in the risk-based inspection (RBI), this study developed the procedures of RBI, in which the risk was estimated by COF through financial loss. And, the RBI program (KS-RBI Ver 3.1) was developed to establish inspection interval based on the risk of the facilities estimated by COF through equipment damage area and financial loss, simultaneously, and the developed RBI program was applied to a petrochemical process. As a result, risks of the facilities estimated by COF through financial loss were similar to risks by COF through the equipment damage area. But, for the case of the facilities using utilities or expensive facilities, the estimation method of the risk by COF through financial loss was more accurate than through equipment damage area.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.8 no.3
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• pp.13-22
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• 2012

According to recent research on leak-rate estimates to assess rupture probabilities of nuclear piping which contains a circumferential surface/through-wall cracks due to PWSCC, i.e., xLPR (Extremely Low Probability of Rupture) program, it has been revealed that the use of crack shape with an idealized circumferential through-wall crack during actual crack growth can lead to overestimate of the leak-rate. Thus, for accurate estimation of the leak-rate during crack growth, the more realistic crack shape that can simulate the crack shape transition from surface crack to through-wall crack should be used. In this context, in the present study, the elastic crack opening displacement of slanted circumferential through-wall crack in thick-walled cylinder was proposed based on 3-dimensional elastic finite element fracture mechanics analyses. To propose the elastic crack opening displacement of slanted circumferential through-wall crack in thick-walled cylinder, the geometric variables affecting crack opening displacement, i.e., thickness of cylinder, reference inner crack length and slant crack ratio were systematically varied. In terms of loading conditions, axial tension, global bending moment and internal pressure were considered. The present results can be applied to calculate the leak-rate considering more realistic crack shape transition from surface crack to idealized through-wall crack, and can be expected to enhance current leak-rate estimation scheme, for instance, in xLPR program etc.

• Membrane Journal
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• v.33 no.6
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• pp.315-324
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• 2023

Ion-exchange membrane (IEM), is a key component that determines the performance of the electro-membrane processes. In this review, the latest research trends in improving the performance of IEMs used in various electro-membrane processes through modification using carbon-based and metal-based nanomaterials are investigated. The nanomaterials can be introduced into IEMs through various methods. In particular, carbon-based nanomaterials can strengthen their interaction with polymer chains by introducing additional functional groups through chemical modification. Through this, not only can the ion conductivity of IEM be improved, but also the permselectivity can be improved through the sieving effect through the layered structure. Meanwhile, metal-based nanomaterials can improve permselectivity through sieving properties using the difference in hydration radius between target ions and excluded ions within a membrane by using the property of having a layered or porous structure. In addition, depending on the characteristics of the binder used, ion conductivity can be improved through interaction between nanomaterials and binders. From this review, it can be seen that the properties of IEMs can be effectively controlled using carbon-based and metal-based nanomaterials and that research on this is important to greatly improve the performance of the electro-membrane process.