• Journal of Hydrogen and New Energy
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• v.24 no.4
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• pp.320-325
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• 2013

TUnitized reversible fuel cells (URFC) combine the functionality of a fuel cell and electrolyzer in one unitized device. For a URFC with proton exchange membrane, a titanium (Ti)-felt is applied to the gas diffusion layer (GDL) substrate at the oxygen electrode, and additionally titanium (Ti)-powders and TiN-powders are loaded in the GDL substrate as a micro porous layer (MPL). Double porous layer with TiN MPL was not acceptable for the URFC because both of fuel cell performance and electrolysis performance are degraded. The double porous layer with Ti-powder loading in the Ti-felt substrate influence rearly for the electrolysis performance. In contrast, the change of pore-size distribution brings a significant improvement of fuel cell performance under fully humidification conditions. This fact indicates that the hydrophobic meso-pores in the GDL play an important role for mass transport.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.429-435
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• 2010

Although recently revised building code requires 15~20% increased thermal insulation performance for window systems, since the code is focusing on winter heat loss, it is not satisfactory to contribute on reducing rapidly rising cooling load in summer. Window systems have great impact on building heat gain and loss. Therefore technological development for window system specialized in shading solar gain in summer is an urgent matter. This study evaluates the performance of sun shading and thermal insulation for blind integrated window system. Also, computer simulation evaluates the effect of heating and cooling energy consumption reduction for an individual unit(floor area of $85m^2$) of a multi-family housing. Physibel Voltra, a heat transfer analysis software, was used to analyse the effect of energy consumption reduction, and the energy load was converted to the cost to compare the actual effect of economical benefit.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2350-2358
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• 2016

The one cycle control (OCC) scheme for active power filters (APFs) has shown excellent harmonic suppression and implementation simplicity. However, its real world application is limited because the non-ideal supply voltage for APFs can influence its performance so that the source currents are still distorted after compensation. This paper proposes a modified one cycle control (MOCC) scheme to improve the performance of three-phase shunt APFs under non-ideal supply voltage conditions. In this paper a detailed mathematical derivation has been presented and the key control law of the MOCC has been developed for adaption to the non-ideal supply voltages, following the control philosophy of simplicity. A relatively simple sequence filter is introduced to extract the harmonic components of supply voltages. The modified scheme can be easily implemented. The proposed control strategy has excellent performance and a 5kVA APF hardware platform has been implemented to validate the feasibility and performance of the proposed strategy.

• Journal of the Korean Institute of Educational Facilities
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• v.27 no.5
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• pp.13-23
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• 2020

From the perspective of smart learning space, this study aims to take a look at the learning space of college students who do online remote learning in the COVID-19 era, and analyze their demands on what smart learning space they want. Furthermore, this study intends to provide valuable implications for the technology-enhanced learning environments by deriving design elements that make up the university's smart learning space. To achieve these goals, we conducted a review of prior studies, interviews with experts, and case analysis on smart learning spaces of major Korean and foreign universities, which are considered as innovative cases. Additionally, in order to confirm the difference between the importance level recognized by the college students and the current performance level for nine components of technology and for ten components of spaces and facilities, a paired t-test and an Importance-Performance Analysis (IPA) were carried out. According to the result of IPA analysis, Internet of Things from the technological aspects, a desk that can supply power and a flexible learning space from the aspects of spaces and facilities were found to have much lower performance than the importance. This result is meaningful in suggesting key design components for smart campus development in the post-COVID-19 world.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.319-324
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• 2010

For the purpose of technological analysis in the marine accidents and their prevention, IMO have made it obligatory to load VDR which is similar to the black box in aircraft. However, in case of body sinkage, capsizing, stranding and plunging which are almost 10% of marine accidents, it is difficult to take out the necessary data from the VDR in order to analyze the cause of them. Therefore, this paper apply the navigation dangerousness evaluation technology to the VDR to improve its performance. And we suggest that the vertical acceleration which is one of the factors for evaluating seakeeping performance of a ship is to be added in the existing VDR record data recommended by IMO.

• Educational Technology International
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• v.23 no.2
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• pp.207-237
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• 2022

As technological changes continue to accelerate every day, meeting the needs of a shifting educational landscape requires leaving an exclusively "in-person" education behind. Gamified learning environments should be carefully designed in light of conflicting studies to suit students' needs. The purpose of this meta-analysis is to draw conclusive results regarding the application of the most commonly used game elements in education, i.e., badges and leaderboards, through a comprehensive analysis of their impact on academic performance in online learning. Review Manager (RevMan 5.4) was used to analyze eligible studies selected from Emerald, SAGE, ERIC, EBSCO, and ProQuest between January 2011 and January 2022. Analyzing 37 studies found that using leaderboards and badges in online education enhanced academic performance when compared to traditional learning without gamification (SMD = 0.39). The badge-only intervention showed a larger effect size (SMD = 0.33) than the leaderboard-only intervention (SMD = 0.27). Badges and leaderboards together exhibited a larger effect size (SMD = 0.48) than individual game elements (SMD = 0.40). The impact of the game elements on academic performance was greater in the humanities (SMD = 0.51) than in STEM fields (SMD = 0.32) and was greater for K-12 students (SMD = 0.63) than for college students (SMD = 0.31). This study contributes to a timely discussion of the use of badges and leaderboards in COVID-19 online learning trends and provides relevant data for designing integrations of online education and gamification models.

• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.61-66
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• 2023

The purpose of this study is to compare and analyze the flame retardant performance of Japanese cypress(Chamaecyparis obtusa) plywood, commonly used in indoor decoration, furniture, and tableware, by treating it with three different fire retardants with different primary ingredients. The experiment was conducted in compliance with Article 31, Paragraph 2 of the Enforcement Decree of the Fire Facilities Installation and Management Act and Articles 4 and 7-2 of the Flame Retardant Performance Standards. After flame time, after glow time, char length, and char area were measured. As a result, first, after flame time was measured at 0 seconds regardless of whether the flame retardant treatment was applied. Second, after glow time was relatively long, measuring 22.7 seconds without treatment, which is likely due to the weak fire resistance and high concentration of carbon monoxide generated by the chemical characteristics of the Japanese cypress itself. Third, it was confirmed that the effects of the primary ingredient, phosphorus, in the flame retardant treatment varied depending on the technological development of the manufacturers of the same species of Japanese cypress plywood. In the future, it is expected that the results of this study will provide fundamental data to select flame retardant treatments that show high flame retardant performance according to the botanical characteristics of the wood.

• Journal of Korea Trade
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• v.26 no.6
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• pp.61-82
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• 2022

Purpose - This study analyzed the effect of obtaining international products and qualification certification on exports according to the suitability evaluation system. Recently, non-tariff barriers have emerged as technical barriers, and the Biden administration is trying to achieve export growth and economic growth by utilizing the demand for conformity assessment following the Fourth Industrial Revolution and the free trade system from the perspective of Korea. Design/methodology - This study analyzed the effect of a manufacturer's product certification acquisition on a company's export performance using Resource-Based View-based multiple regression analysis. To this end, concentration validity was confirmed through Factor analysis and Cronbach's alpha, and correlation analysis was performed to verify discriminant validity. Findings - Product certification and qualification have a positive impact on the company's export performance. In particular, technological dynamism and relationship control have had a significant impact. Originality/value - Considering that the Conformity Assessment Management Act will take effect in earnest in 2022, this study is believed to suggest that companies that have been certified to meet international standards may improve their export performance and increase their value in the future. International market.

• Journal of Distribution Science
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• v.22 no.1
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• pp.1-12
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• 2024

Purpose: Rapid technological advancements and information dissemination have catalyzed a steep upsurge in the distribution of ornamental flower arrangement products, effectively meeting the burgeoning demands of customers. This research endeavours to elucidate the relationship between market orientation (MO) and competitive advantage (CA), with the intermediary role of marketing performance (MP) within Denpasar's flower arrangement retail sector. Research Methods: Conducted within a Denpasar-based flower shop, the study engaged 94 respondents through a questionnaire-based data collection methodology. Utilizing a saturated sampling approach, the sample size equated to the population size. The analysis employed SmartPLS, a robust statistical tool. Results: The study findings reveal that MO does not exert a statistically significant direct impact on CA. Nevertheless, MO exhibits a substantively positive and statistically significant influence on MP, which, in turn, substantially and significantly contributes to CA. For flower arrangement business owners, it is imperative to orchestrate effective control over their marketing performance. Conclusion: This involves nurturing enduring customer and employee relationships by steadily implementing market-oriented distribution strategies. By doing so, customer satisfaction and growth, pivotal in bolstering marketing performance, can be adeptly sustained, ultimately culminating in attaining competitive advantage.

• 대한공업교육학회지
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• v.40 no.2
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• pp.175-195
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• 2015

This study is aimed at exploring the educational meaning of cooperative hands-on activity in the technology subject from the perspective of a student who is an education consumer. For this purpose, this study selected 12 first year student of a middle school located at G City of Gyeonggi-do Province as research participants through purposeful sampling, and conducted an in-depth interview and group discussion based on stimulated recall questionary techniques. This study utilized area analysis, classification analysis and component analysis as a data analysis method, and secured the verity of the research through the examination between research participants and triangulation. As a result of this research work, it was found that the cooperative hands-on class in the technology subject had the meaning of 'Space between a burden and excitement about the technical making', 'Clue and ignition point of technological problem solving', and 'Self-discovery through Technical capability'. To be more concrete, 'Space between a burden and excitement about the technical making' means that students, whose usual school record is excellent, felt great psychological burdens of performance assessment, but their pre-experience and interest in 'Making' induced them to feel exhilaration of hands-on activity. 'Clue and ignition point of technological problem solving' means that students get to make much of the understanding & formation of the relationship with teammates in the process of resolving an unfamiliar hands-on activity task and to have the continuous problem-solving ability. 'Self-discovery through Technical capability' means that students get to realize the importance of learning experience of one's own making through hands-on activity learning, which could be the opportunity to meet the operant demands of the inner side. This study hopes that such results could be utilized as the basic data needed for designing the hands-on activity education in the technology subject more meaningfully and systematically for the time to come.