• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.65-68
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• 2008

Generally CCM (cold crucible melting) is not suitable for melting glass. However, in this study we described the quantitative relationship between the basic property of glass and power balance, the power absorption in the melt, the losses in the coil and the cold crucible, for melting glass in CCM. The dependence of power balance on the applied frequency and the electric conductivity has been found. Above 300 kHz, the glass (B) contained alkali ion which has the low resistance $3.0{\Omega}{\cdot}cm$ at $900^{\circ}C$ and $1.36{\Omega}{\cdot}cm$ at $1,100^{\circ}C$ was melted easily and 60% of the overall power was absorbed in the melt and 30% and 10% of the overall power was lost in the cold crucible and coil respectively. Under the same condition, the glass (A) contained non-alkali ion was not melted easily and 50% of the overall power was absorbed in the melt and 40% and 10% of the overall power was lost in the cold crucible and coil respectively. In conclusion, the small absorbed power of the overall power in melt prevented a successful melting as for glass A, and the successful melting depends on the relative size of the absorbed power in melt irrespective of the melting volume. Hence, as typical for direct induction heating method(CCM), the successful melting strongly depended on the chosen working frequency based on electric conductivity of glass, power balance and the control of the critical power which was absorbed in melt.

• Journal of Internet of Things and Convergence
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• v.7 no.2
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• pp.21-29
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• 2021

In this study, it is necessary to supplement the Korean language curriculum in order for international students to adapt and settle in Korea in an era where education is being transformed into future education due to the 4th industry. In the KFL (Korean as a Foreign Language) situation encountered by international students, they suffer from difficulties in university mathematics due to communication problems due to lack of language ability, which is one of the stress factors for cultural adaptation in the Korean language education program. To solve this problem, we analyzed ESL programs in English-speaking countries and KSL programs in Korea to set educational goals, curriculum, and educational methods to achieve goals for international students, and to establish curriculum and learning processes. Therefore, the Korean language education program (KSL program) for foreign students in the Korean language curriculum should also be supplemented by accepting the advantages of setting accurate goals for the ESL program and linking it with university graduation in the curriculum of English-speaking countries. In addition, for international students to learn Korean, an integrated Korean language education course and management system using IT suitable for the 4th industrial age is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.754-762
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• 2021

Seamless wireless communication network access technology enables users to guarantee service continuity. Hence, it is necessary for disaster situations in which network service may be interrupted. The Multi-path router is a technology to improve network stability and strengthen field operability, particularly in a disaster environment where network failure can occur by providing high-performance data transmission using multi-communication networks and network security by VPN-based wireless IP. In this paper, a prototype system for an MPR-based wireless communication network was proposed to improve the operation performance for disaster field investigation applications. A comparative experiment was performed on various data transmission performances with the existing single wireless communication network. In addition, another experiment was conducted by measuring the data packet transmission and receiving performance in the existing/new wireless communication system first and then assessing the UDP transmission performance in a single router environment to understand the transmission capability of the new MPR. The experimental results showed that the sending and receiving performance was improved by approximately double that of the existing single wireless communication system. The proposed prototype system is expected to allow users to share and disseminate collected on-site data more quickly and efficiently during a disaster site investigation.

• Journal of Music and Human Behavior
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• v.19 no.1
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• pp.93-112
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• 2022

The purpose of this study was to compare participants' perceived emotion following harmonic changes in music. In this study, 144 participants, aged 19 to 29 years, listened to music online that included low to high harmonic progression in tonal music (major-minor). After listening to each piece of music, participants were asked to rate 4 items using a 7-point Likert scale: emotional potency, arousal, degree to which the harmony impacted the listener's emotions, and listener's preference for the music. There were significant differences between each of the four items upon the level of harmonic progression. When the participants were divided into two groups (i.e., those with a background in music and those with no background in music), there was a significant difference between the groups in terms of emotional potency, but there was no significant interaction effect. This study confirmed that various emotional responses in listeners can be induced by controlling the exogenous variables in musical excerpts. Based on this, it is expected that the harmonic progression level can be provided to the client to be used as an effective therapeutic tool in music therapy intervention.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.593-615
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• 2022

This study aimed to analyze the relationship between the observation ability and scientific creativity of elementary students through observation learning of outdoor plants and to identify the factors that influence the two constructs. The study recruited 21 fifth-graders in Seoul. After evaluating observation ability and scientific creativity through observation tasks, qualitative data were obtained through interviews with students about their observation of the plants. Additionally, the study collected various materials, such as the observation records and worksheets of the students to verify the validity of research. The main results of this study are as follows. First, the students were first classified into four groups according to levels of observation ability and scientific creativity. The result demonstrated that the higher the level of observation ability, the higher the level of scientific creativity. Second, observation ability and scientific creativity pointed to a positive correlation. Furthermore, originality, which is one of the components of scientific creativity, indicated a weak positive correlation with observation ability. Third, the factors that influenced observation ability were frequency of plant observation and interest and cooperation in observation learning, and those of scientific creativity were observation ability and the level of plant-related knowledge. Lastly, the study discussed educational methods for improving observation ability and scientific creativity.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.387-394
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• 2022

120 kVp FBP reconstruction image standard by using raw data after scanning by changing tube voltage among the NECK CT protocols that are broad applied in clinical practice using a human phantom including thyroid gland The usefulness of the DLIR reconstruction technique was investigated. As a result, CTDIvol decreased when the DLIR reconstruction technique was applied, and in particular, the image quality obtained under the same standard scanning conditions at a lower dose for ASIR-V and DLIR reconstruction was reached than when FBP was applied at the same kVp In addition, as a result of SNR and CNR analysis, the DLIR reconstructed image was analyzed with high SNR and CNR values, and SSIM analysis, the SSIM index of the 100 kVp, DLIR reconstructed image was measured to be close to 1, and it was analyzed that the similarity of the reconstructed image to the original image was high (p>0.05). If the results of this study are used to supplement clinical image evaluation and further develop an algorithm applicable to various anatomical structures, it is thought that it will be useful for clinical application as it is possible to maintain the image quality while lowering the examination dose.

• Journal of Music and Human Behavior
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• v.20 no.1
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• pp.1-19
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• 2023

This study explored the role and characteristics of music that contributed to experiences of catharsis in music. An empirical phenomenological study was conducted to explore catharsis with 12 adults. Phenomenological reduction, change of attitude, literature interpretation, and hermeneutic circle were used for data collection and analysis. As a result, three categories, five themes, and 11 sub-themes were identified. The first category, here and now in music consisted of two themes: aesthetic experiences and expansion of musical novelty. The second category, inner connection through music consisted of one theme, re-experience of internal emotions. The third category, immersion and engagement in music consisted of two themes: ventilating or deepening of emotions and internal dynamics. Based on these results, the cathartic characteristics of music are discussed. First, the aesthetics and novelty of music kept participants fully stay in music. Second, music induced a re-experiencing of emotions by triggering memories or stimulating unresolved emotions. Third, the elements of music promoted emotional ventilation, deepening, and internal dynamics. This study is meaningful because it qualitatively examined the roles and characteristics of music that contribute to cathartic experience in the general adult population.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.3-11
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• 2023

Building information modeling (BIM) can help to visualize and manage the building-related information at the object-based level, and it is possible to help link the tasks in the network of Hanok construction. While many studies have significant interest in using BIM for modern construction, there is only few studies to observe the use of BIM for traditional construction, commonly called Hanok construction in South Korea. Hence, the main goal of this study is to develop a system dynamic model for investigating how the BIM can be widely used for Hanok construction. To this end, this study identified the factors influencing the BIM uses for the Hanok construction, developed a causal loop diagram (CLD) to investigate the interrelationships among the factors, and provided a final model based on the mathematical definitions. Based on the scenario analysis, it is demonstrated that the support to building Hanok and education cost for BIM positively influence activating and using the BIM for the Hanok construction. Based on the dynamics of the factors identified in this study, it is important to consider expanding support for Hanok construction and education cost for BIM to successfully integrate and utilize BIM in the construction industry.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.361-372
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• 2023

In this study, three luxury fashion start-up platforms, Balaan, Trenbe, and Must-it, were selected as research subjects. The purpose of this study is to compare and analyze the marketing mix strategies of each of the three online sites. The results of our study are as follows. First of all, the product strategies of the three luxury platform companies are characterized by the composition of products from high-end brands to SPA brands, and product composition such as kids, home living, Used goods and art in addition to women's and men's wear. In addition, the pricing strategies of luxury platforms show price differences depending on the luxury platform even for the same product. It is shown as a structure that directly determines margin. Therefore, in order to secure an edge in price competitiveness, each platform provided discount coupons and savings that are not available in offline stores such as department stores, providing opportunities to purchase luxury goods at a lower price than offline stores.Lastly, the sales promotion strategies of the three luxury platform companies was used include price discount promotions such as price discounts, discount coupons, and regular sales, and value-added sales such as membership registration/review points, events, product information, delivery services, social contribution activities, and SNS utilization.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.158-163
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• 2023

This study aimed to determine mercury (Hg), methylmercury (MeHg), and selenium (Se) levels in deep-sea fishes distributed in Gyeonggi-do, South Korea. Concentrations of Hg, MeHg, and Se were measured by using a mercury analyzer and Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The average content (mg/kg) in the seafood samples was as follows: Hg, 0.7647 (0.0182-5.3620), MeHg, 0.0764 (0.0096-0.8750), and Se, 0.4728 (0.1075-3.5100). All the levels of MeHg were below the recommended standards of the Ministry of Food and Drug Safety i.e., <1.0 mg/kg. Recent studies have shown that Se prevents Hg toxicity. The average daily intake in humans was 3.3 ㎍/kg, which was lower than the recommended amount (50-200 ㎍/person/day). The weekly intake of Hg and MeHg was calculated to be 6.07% and 1.90%, respectively, of the provisional tolerable weekly intake (PTWI). This study showed that the weekly intake of Hg and MeHg from abyssal fish was less than the PTWI recommended by the Joint FAO/WHO expert committee on food additives. Therefore, the levels reported in this study are presumed to be adequately safe.