• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.1
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• pp.49-62
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• 2018

Net community production (NCP), defined as the difference between net primary production and respiration of heterotrophs, has been used as a measure of oceanic biological carbon pump. This paper summarizes the theoretical background and experimental methods for the estimation of NCP based on $O_2/Ar$ measurements ($O_2/Ar-NCP$). The high frequency measurements of $O_2/Ar-NCP$ (<1 min) is a significant enhancement over the conventional measures of biological pump, such as new production and export production. This paper also introduces some of important works as to the comparison between $O_2/Ar-NCP$ and other measures of biological pump, the distributions of $O_2/Ar-NCP$ in the oceans, and the correlation of $O_2/Ar-NCP$ with various oceanic parameters, including community structures.

• Journal of the Korean Magnetics Society
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• v.9 no.3
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• pp.159-165
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• 1999

Structural, magnetic and magnetoresistance behavior of NiFe/Ag multilayers prepared by a magnetron sputter under an Ar and $Ar/H_2$ atmosphere was studied. It was difficult to make a uniform multilayer by using an Ar atmosphere. However, the uniform multilayers could be fabricated by using an $Ar/H_2$ atmosphere. This was thought to be due to decrease in the energy of the sputtered atom and Ar content of the film. Typical magnetoresistance behavior of the discontinuous NiFe/Ag multilayers appeared when the uniform multilayer was formed and annealed. Substrate temperature did not improve the uniformity of the multilayers. Above 20$0^{\circ}C$ of the substrate temperature, the films were almost formed into granular alloys rather than multilayers.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.236-249
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• 2021

Due to the spread of AR/VR headset, AR/VR contents market gains huge interests. However, various obstacles such as discomfort that restricts usability and absence of standard to evaluate usability block the growth of AR/VR contents industry. To overcome these problems, this study tries to develop an evaluation scheme for the usability of R/VR contents and a prototype system. The proposed evaluation system divides usability related items into safety and convenience items and performs evaluation by item through automatic and experience evaluation by system and experts/experience teams according to characteristics, and comprehensively evaluates the usability of AR/VR content. In this study, a detailed process fo usability evaluation and the prototype system are developed to verify the evaluation scheme. Developed scheme is expected to help the AR/VR content industry overcome the usability issues, and develop high-quality AR/VR content.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.474-488
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• 2021

The application of Augmented Reality(AR) technology is visible in medical procedures, education, marketing, and journalism. By experimenting, this study examines how the evaluation of the three elements of augmented reality news contents(visual image, storytelling, interactivity) affects immersion and information acquisition. Specifically, a 2 (video technology: AR vs. general) × 2 (news type: disaster vs. sports) between-subject design was examined. Results showed that the evaluation of all three elements was higher when viewing AR news than when viewing general news. The level of immersion was higher when viewing AR news, and the evaluation of storytelling and interactivity had positive effect on the level of immersion regardless of the news types. However, the evaluation of visual images did not affect the level of immersion. Information acquisition was higher after viewing AR news, yet the effect of the evaluation of the three elements on information acquisition had not been found. Implication and discussion of the study were added in the end.

• Atmosphere
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• v.33 no.4
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• pp.399-411
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• 2023

This study compares the three detection algorithms of East Asian summer atmospheric rivers (ARs). The algorithms developed by Guan and Waliser (GW15), Park et al. (P21), and Tian et al. (T23) are particularly compared in terms of the AR frequency, the number of AR events, and the AR duration for the period of 2016-2020. All three algorithms show similar spatio-temporal distributions of AR frequency, centered along the edge of the North Pacific high. The maximum AR frequency gradually shifts northward in early summer as the edge of the North Pacific High expands, and retreats in late summer. However, the detailed pattern and the maximum value differ among the algorithms. When the AR frequency is decomposed into the number of AR events and the AR duration, the AR frequencies detected by GW15 and P21 are equally explained by both factors. However, the number of AR events primarily determine the AR frequency in T23. This difference occurs as T23 utilizes the machine learning algorithm applied to moisture field while GW15 and P21 apply the threshold value to moisture transport field. When evaluating AR-related precipitation, the ARs detected by P21 show the closest relationship with total precipitation in East Asia by up to 60%. These results indicate that AR detection in the East Asian summer is sensitive to the choice of the detection algorithm and can be optimized for the target region.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.565-574
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• 1993

The Ar/Ar- $H_{2}$ plasma method Lvas applied to reduce and refine high purity Nb metal. Inaddition, the reaction between molten Nb metal and hydrogen were also analyzed in the Ar-(20%)$H_{2}$plasma. The metallic Nb of 99.5wt% was obtained at the ratio of $C/Nb_{2}O_{5}$=5.00 in the Ar plasma reductionand the $O_2$ loss from the thermal decomposition of niobium oxides did not take place. In the Ar-(20%)Hi plasma the metallic Nb of 99.8wt% was produced at the ratio of $C/Nb_{2}O_{5}$=4.80. It was observedthat a major reaction of the deoxidation was the reaction with H, Hi, and a deoxidation by the evaporationof $NbO_x$ did not occur but a mass loss of Nb did by a "splash" effect. The deoxidation reaction rateobeyed the 1st order reaction kinetics and the reaction rate constant(k') of deoxidation was $7.8 \times 10_{-7}$(m/sec).The solubility of hydrogen in Nb metal was 60ppm and it was larger than the solubility of molecularstate hydrogen by 40ppm in the Ar-(20%)$H_{2}$ plasma method. A saturation was within 60sec anda hydrogen content was reduced below lOppm by a Ar plasma re-treatment.by a Ar plasma re-treatment.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.755-759
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• 2013

The etch rate and etch profile of Si was investigated when Ar was added to an $SF_6$ plasma in the etch step of the Bosch process. A Si substrate was etched with the Bosch process using $SF_6$ and $SF_6$/Ar plasmas, respectively, in the etch step to analyze the effects of Ar addition on the etch characteristics of Si. When the Ar flow rate in the $SF_6$ plasma was increased, the etch rate of the Si substrate increased, had a maximum at 20% of the Ar flow rate, and then decreased. This was because the addition of Ar to the $SF_6$ plasma in the etch step of the Bosch process resulted in the bombardment of Ar ions on the Si substrate. This enhanced the chemical reactions (thus etch rates) between F radicals and Si as well as led to sputtering of Si particles. Consequently, the etch rate was higher more than 10% and the etch profile was more anisotropic when the Si substrate was etched with the Bosch process using a $SF_6$/Ar (20% of Ar flow rate) plasma during the etch step. This work revealed a feasibility to improve the etch rate and anisotropic etch profile of Si performed with the Bosch process.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.143-152
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• 2024

Due to COVID-19, domestic Duty-free shops have been severely impacted, and with the expansion of the untact market, the proportion of mobile shopping has increased. So far, mobile duty-free shop AR shopping is not active, and related research is scarce. Therefore, we aims to enhance Duty-free Shopping APPs with AR technology by researching the needs of foreign users. First, in the mobile duty-free shop app, the AR shopping interface must be in a prominent position to be open and easy to use. Second, there should be an explanation or help for location and function so that all users can easily recognize the AR shopping interface. Third, when wearing duty-free items in the AR shopping interface or adding them to the storage and shopping cart of interest, the interface must be simple and flexible, making it convenient to use and operate. Fourth, technical improvements must be made to prevent errors. We expect that the research will help develop AR shopping technology and domestic duty-free shop AR shopping technology and revitalize online and offline duty-free shops.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.400-405
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• 2015

Traditional anti-reflective (AR) coating films prepared using tetraethylorthosilicate (TEOS) as a precursor absorbs water easily in addition to having a weak abrasion resistance. To improve the transmittance, hydrophobicity and abrasion resistance of AR coating film, various AR coating films were prepared using methyltrimethoxysilane (MTMS) as a precursor in addition to introducing a fluoroalkylsilane, acid catalyst, base catalyst and acid-base two step catalyst. The prepared AR coating films were then characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), pencil scratch hardness test and cross-cut test. As a result, the transmittance of bare glass was 90.5%, while that of AR coating glass increased to 94.8% at curing temperature of $300^{\circ}C$. When the fluoroalkylsilane was added, the water contact angle of AR coating film increased from $96.3^{\circ}$ to $108^{\circ}$, indicating that the hydrophobicity of the film was greatly improved. The abrasion resistance of AR coating film was also improved by the acid catalyst, whereas the transmittance increased by the base catalyst. In the case of AR coating film prepared using an acid-base two step catalyzed reaction, both the transmittance and abrasion resistance of the film was synergistically enhanced as compared with those of AR coating films prepared without introduction of a catalyst.

• Spatial Information Research
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• v.22 no.2
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• pp.1-9
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• 2014

UN-REDD (United Nations programme on Reducing Emissions from Deforestation and forest Degradation in Developing Countries) and AR-CDM (Afforestation/Reforestation-Clean Development Mechanism) is currently being emerged as one of important mechanism to reduce carbon dioxide in relation to the deforestation. Discussion on North Korea as UN-REDD/AR-CDM project target continues with a view to preventing deforestation and to securing CER(certified emission reduction) for South Korea. The forests in Mt. Baekdu are degraded, deforestation is occurred, nevertheless, portion of forested area is still high, where both REDD and AR-CDM investment potential are quite high. Accordingly, this study is intended to explore a simultaneous registration potential to UNREDD/AR-CDM for Mt. Baekdu although separate registration to UN-REDD or AR-CDM has already gained worldwide recognition as a typical method in the process of GHG (Greenhouse Gas) reduction project. The results indicate that selecting UN-REDD or AR-CDM in accordance with sub-watershed forest condition could capture 53.2% more carbon dioxide than REDD alone and 21.9% more than AR-CDM alone. It is anticipated that this research output could be used as a realistic evidence to introduce carbon sequestering project in accordance with sub-watershed forest condition.