• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.153-164
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• 2019

To develop a high performance SCR catalyst which has better specific surface area, lightness of weight and fast temperature response than those of existing commercial SCR catalyst, metal foam type SCR catalysts were prepared by washcoating with vanadium, tungsten and binder. The de-NOx performance test of the prepared catalysts was carried out on atmospheric micro-test unit at lab. scale according to space velocity variation and temperature change, and the characteristics of them were analyzed by Porosimeter, SEM(scanning electron microscope), EDX(energy dispersive x-ray spectrometer), ICP(inductively coupled plasma) and Stereomicroscope. The NOx reduction performance decreased as the space velocity increased and was found to be the best at 3.5 wt.% contents of the vanadium and tungsten. It was found that the larger amount of binder was added, the worse the NOx reduction performance was, which was considered to be that the number of active sites of the prepared catalyst surface was occupied by the binder. We found that the amount of binder to be added to prepare the catalyst should be properly controlled by the condition of coated catalyt surface.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.372-377
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• 2018

MgO or gadolinium-doped ceria (GDC, $Ce_{0.9}Gd_{0.1}O_{2-{\delta}}$) was added as a promoter to improve the oxygen transfer kinetics of $MgMnO_3$ oxygen carrier material for chemical looping combustion. Neither MgO nor GDC reacted with $MgMnO_3$, even at the high temperature of $1100^{\circ}C$. The average oxygen transfer capacities of $MgMnO_3$, 5 wt% $MgO-MgMnO_3$, and 5 wt% $GDC-MgMnO_3$ were 8.74, 8.35, and 8.13 wt%, respectively. Although the addition of MgO or GDC decreased the oxygen transfer capacity, no further degradation was observed during their use in 5 redox cycles. The addition of GDC significantly improved the conversion rate for the reduction reaction of $MgMnO_3$ compared to the use of MgO due to an increase in the surface adsorption process of $CH_4$ via oxygen vacancies formed on the surface of GDC. On the other hand, the conversion rates for the oxidation reaction followed the order 5 wt% $GDC-MgMnO_3$ > 5 wt% $MgO-MgMnO_3$ >> $MgMnO_3$ due to morphological change. MgO or GDC particles suppressed the grain growth of the reduced $MgMnO_3$ (i.e., (Mg,Mn)O) and increased the specific surface area, thereby increasing the number of active reaction sites.

• Korean Journal of Metals and Materials
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• v.47 no.2
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• pp.59-70
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• 2009

This study is concerned with the correlation between microstructure and mechanical properties in heat affected zones (HAZs) of API X80 pipeline steels containing complex oxides. Three kinds of specimens were fabricated by varying alloying elements of Ti, Al, and Mg to form complex oxides, and their microstructures, Vickers hardness, Charpy impact properties were investigated. The number of complex oxides increased as the excess amount of Ti, Al, and Mg was included in the steels. The simulated HAZs containing a number of oxides showed a high volume fraction of acicular ferrite region because oxides acted as nucleation sites for acicular ferrite. According to the correlation study between thermal input, volume fraction of acicular ferrite region, and Charpy impact properties, the ductile fracture occurred predominantly when the volume fraction of acicular ferrite region was 65% or higher, and the Charpy absorbed energy was excellent over 200 J. When the volume fraction of acicular ferrite region was 35% or lower, the Charpy absorbed energy was poor below 50 J as the brittle cleavage fracture occurred. These findings suggested that the active nucleation of acicular ferrite in the oxide-containing steel HAZs was associated with the great improvement of Charpy impact properties of the HAZs.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.21-32
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• 2022

The importance of the classical theme of how the Top-of-Atmosphere (TOA) and Top-of-Canopy (TOC) reflectance of high-resolution satellite images match the actual atmospheric reflectance and surface reflectance has been emphasized. Based on the Radiometric Calibration Network (RadCalNet) BTCN and BSCN data, this study compared the accuracy of TOA and TOC reflectance products of the currently available optical satellites, including KOMPSAT-3, WorldView-2, and Pléiades-1A image sets calculated using the absolute atmospheric correction function of the Orfeo Toolbox (OTB) tool. The comparison experiment used data in 2018 and 2019, and the Landsat-8 image sets from the same period were applied together. The experiment results showed that the product of TOA and TOC reflectance obtained from the three sets of images were highly consistent with RadCalNet data. It implies that any imagery may be applied when high-resolution reflectance products are required for a certain application. Meanwhile, the processed results of the OTB tool and those by the Apparent Reflection method of another tool for WorldView-2 images were nearly identical. However, in some cases, the reflectance products of Landsat-8 images provided by USGS sometimes showed relatively low consistency than those computed by the OTB tool, with the reference of RadCalNet BTCN and BSCN data. Continuous experiments on active vegetation areas in addition to the RadCalNet sites are necessary to obtain generalized results.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.504-513
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• 2022

Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.93-100
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• 2022

In the era of information overload on the Internet, the recommendation system, which is an indispensable function, is a service that recommends products that a user may prefer, and has been successfully provided in various commercial sites. Recently, studies to reflect the rating time of items to improve the performance of collaborative filtering, a representative recommendation technique, are active. The core idea of these studies is to generate the recommendation list by giving an exponentially lower weight to the items rated in the past. However, this has a disadvantage in that a time function is uniformly applied to all items without considering changes in users' preferences according to the characteristics of the items. In this study, we propose a time-aware collaborative filtering technique from a completely different point of view by developing a new similarity measure that integrates the change in similarity values between items over time into a weighted sum. As a result of the experiment, the prediction performance and recommendation performance of the proposed method were significantly superior to the existing representative time aware methods and traditional methods.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.57-67
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• 2022

Tower cranes have an unstable superstructure, which means that there is a very high risk of accidents. It is necessary to establish preventive measures to ensure the safety of tower cranes at a time when active efforts are being made to reduce safety accidents involving tower cranes. As such, the purpose of this study is to analyze disaster cases to ensure the safety of tower cranes. For this study, 260 cases of tower crane disasters filed with the Korea Occupational Safety and Health Agency from July 2012 to July 2020 were analyzed. Through this analysis, it was found that lifting work was the most common of the work types, at 45.3%; while of the types of disasters, accidents caused by falls were the most common type, at 35.8%. In addition, with regard to the cause of accidents, work method defects was found to be the highest, at 38.8%. In the future, the findings of this study will be used as basic data to guide the establishment of policy to prevent tower crane accidents.

• Journal of Advanced Technology Convergence
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• v.1 no.2
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• pp.01-09
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• 2022

Recently, safety issues in companies and public institutions are no longer a task that can be postponed, and when a major safety accident occurs, not only direct financial loss, but also indirect loss of social trust in the company and public institution is greatly increased. In particular, in the case of a fatal accident, the damage is even more serious. Accordingly, as companies and public institutions expand their investments in industrial safety education and prevention, open AI learning model creation technology that enables safety management services without being affected by user behavior in industrial sites where high-risk situations exist, edge terminals System development using inter-AI collaboration technology, cloud-edge terminal linkage technology, multi-modal risk situation determination technology, and AI model learning support technology is underway. In particular, with the development and spread of artificial intelligence technology, research to apply the technology to safety issues is becoming active. Therefore, in this paper, an open cloud platform design method that can support AI model learning for high-risk site safety management is presented.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.42-52
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• 2022

The goal of this study is to analyze the value of Kanga as an ethos of the Swahili culture. The theoretical background of the research method was the analysis of the domestic and foreign literature, journals, and research data from various internet sites related to the subject, and the conclusion was drawn based on these studies. With the spread Pan-Africanism, the interest in African ethos has become a source of inspiration for contemporary fashion. Moreover, as a symbol of Swahili culture in East Africa, Kanga has been developed by embracing its own diverse cultures, The unique feature of Kanga is that it can easily be transformed created ceaselessly and creatively. Consequently, the following results were obtained based on the theoretical content. Firstly, as a representative of Women's Voice, Kanga serves as an outlet for the voices of women coming from a poor social status under the political background in East Africa. Secondly, as a Reliable Advocate, Kanga performs the positive functions as a medium of communication through its traditional usage and distinctive arrangement of clothes. Thirdly, as a Versatile Messenger, the uniqueness of Kanga with the external elements in most interestingly and active mannerly, and it has become the value of communication channel which clearly inspired the fashion designers. I believe that it will be interesting and meaningful to study the strategies on the social role of Kanga in the future which has started receiving more attention in the 21st century. And it can be said that Kanga's unique identity lies in the attraction and value which influences contemporary fashion.

• Fashion & Textile Research Journal
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• v.24 no.1
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• pp.81-94
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• 2022

The purpose of this study is to analyze the trends of MZ generation's lifestyle-related research from 2010 to 2020. As a result of searching keywords such as MZ generation's and lifestyle using academic database search sites, a total of 218 cases were used as analysis data to conduct frequency and content analysis. First, research type was 74 dissertations(34.6%), 144 journals(65.4%). The study of MZ generation was relatively active in journals. Second, the current status of academic field was 85(39.7%) in the social field, followed by 66(30.8%) in the arts/physical education, 21(9.8%) in the complex studies, 16(7.5%) in education, 15(7.0%) in nature, 6(2.8%) in engineering, 4(1.9%) in humanities, 1(0.5%) in agriculture/marine. Third, the current status of MZ generation research topics is 54 social participations(25.3%), 35 fashion/beauty(16.3%), 31 social/organizational adaptations(14.5%), 25 cultural/leisure activities(11.7%), 24 design/development projects(11.2%), 21 economic/employment/job projects(9.8%), 11 educational/career/experiences(5.1%), 9 self-concepts(4.2%), 4 welfare services(1.9%). Fourth, the current status of MZ generation research methods was quantitative research(survey/experiment) 125(58.4%), qualitative research(depth interview/participant observation) 42(19.6%), theory/literature research 35(16.4%) and mixed research 12(5.6%). Fifth, the study on the lifestyle of the MZ generation was conducted in four cases, one in 2016, one in 2019, two in 2020. This study is meaningful in that it grasped the overall flow of data of information exchange that can share the research trends of the MZ generation and suggested the basic data on the direction of future research, the individual tendency, behavior, and lifestyle characteristics of the MZ generation.