• 아태비즈니스연구
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• 제13권2호
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• pp.23-37
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• 2022

Purpose - The purpose of this paper is to analyze the dynamic factors of the daily FX implied volatility based on the fractional integration methods focusing on long memory feature and structural changes. Design/methodology/approach - This paper uses the daily FX implied volatility data of the EUR-USD and the JPY-USD exchange rates. For the fractional integration analysis, this paper first applies the basic ARFIMA-FIGARCH model and the Local Whittle method to explore the long memory feature in the implied volatility series. Then, this paper employs the Adaptive-ARFIMA-Adaptive-FIGARCH model with a flexible Fourier form to allow for the structural changes with the long memory feature in the implied volatility series. Findings - This paper finds statistical evidence of the long memory feature in the first two moments of the implied volatility series. And, this paper shows that the structural changes appear to be an important factor and that neglecting the structural changes may lead to an upward bias in the long memory feature of the implied volatility series. Research implications or Originality - The implied volatility has widely been believed to be the market's best forecast regarding the future volatility in FX markets, and modeling the evolution of the implied volatility is quite important as it has clear implications for the behavior of the exchange rates in FX markets. The Adaptive-ARFIMA-Adaptive-FIGARCH model could be an excellent description for the FX implied volatility series

• 복식문화연구
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• 제30권4호
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• pp.529-547
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• 2022

The purpose of this study was to understand the concept, form, and structure of the bata de cola through an investigation of the history of the costume and a study of the suitability of its functional elements during performance of 'Caña Flamenco'. Traditionally, Flamenco dance dresses were made by Spanish women from the lower classes, and the 'upward flow' of the dresses represented the women's individuality and unique style. The bata de cola, which appeared later, was an evolution of the Flamenco dress that was influenced by costume styles and silhouettes of the 19th and early 20th centuries, and it was made famous by Flamenco dancers. For practical costume production, a Flamenco artist who had performed in Spain and Korea was proposed as a study participant. The study was conducted using a stepwise wearing evaluation method whereby the Flamenco artist wore prototype dresses and evaluated whether they were practical for the required dance movements or not. A final bata de cola pattern was derived after the experiment was repeated five times based on the feedback of the Flamenco artist, focusing on the factors that were considered most important. Using stepwise clothing evaluation of the prototype, a costume that enabled the Flamenco artist to implement optimal movements was successfully produced.

• Animal Systematics, Evolution and Diversity
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• 제22권1호
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• pp.29-35
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• 2006

Two ciliates of suborder Euplotina collected from the two habitats (estuarine littoral and sewage treatment plant) in Ulsan, Korea were Euplotes charon ($M\ddot{u}ller$, 1773) and Diophrys oligothrix Borror, 1965. These two species are reported for the first time from Korea. The description was based on the observation of living and silver impregnated specimens. Diagnostic characteristics of these species are as follows. E. charon: size in vivo about $90-130\times65-80{\mu}m$, adoral zone of membranelles over 79.5% of cell length with 54-80 adoral membranelles; right margin of the peristome shaped sinusoidal form and passed through adoral zone of membranelles; buccal cavity wide anteriorly; 10 frontoventral, 5 transverse, 4 caudal cirri, 12 dorsal kineties, mid-dorsal kinety with 21 -25 dorsal bristles; silver-line system double-eurystomus type. D. oligothrix: size in vivo about $80-90\times30-70{\mu}m$; body shape ovoid with prominent right concave posterio-lateral end, two irregular elongated macronuclei with one micronucleus, respectively; 7 fronto-ventral, 5 transverse, 2 left marginal and 2 caudal cirri, 4 dorsal kineties with prominent bristles about $9-14{\mu}m$ long in vivo.

• International Journal of Advanced Culture Technology
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• 제11권1호
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• pp.253-262
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• 2023

Chinese traditional patterns, which are part of our national precious heritage, have a long history. Tiger culture plays a very important role in folk art. In modern society, it is a symbol of human spirit and morality. The tiger pattern is also a unique traditional pattern in Chinese folklore. From the Spring and Autumn period to modern society, the tiger pattern has evolved in form through thousands of years of development. It is also a representative intangible cultural heritage in contemporary times. It plays a special role in the cultural exchange of different regions, resulting in the generation of the creation of folk art with great local characteristics. Therefore, traditional tiger patterns are an important part of traditional Chinese folk culture and art. In this study, by analyzing the development and evolution history of Chinese traditional tiger patterns, the application methods of Chinese traditional tiger patterns were summarized, the rich cultural connotation, artistic characteristics and application of traditional tiger pattern in modern fashion design were discussed. In contemporary design, the new and improved tiger pattern styles were explored, intangible cultural heritage was interpreted and inherited, and the cultural and artistic values contained therein were extracted. The author combined with modern fashion design, according to people's aesthetic taste and design principles, it is recreated,so that the traditional pattern has certain characteristics of The Times.But at the same time it retains its original character,and the traditional tiger pattern was inherited and the cultural connotation of clothing design was enriched.

• 한국정밀공학회지
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• 제14권12호
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• pp.24-29
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• 1997

Recently, Genetic Algorithm(GA), which is a stochastic direct search strategy that mimics the process of genetic evolution, is widely adapted into a search procedure for structural optimization. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GA is very simple in their algorithms and there is no need of continuity of functions(or functionals) any more in GA. So, they can be easily applicable to wide area of design optimization problems. Also, owing to multi-point search procedure, they have higher porbability of convergence to global optimum compared to traditional techniques which take one-point search method. The methods consist of three genetics opera- tions named selection, crossover and mutation. In this study, a method of finding the omtimum size and topology of drilling machine is proposed by using the GA, For rapid converge to optimum, elitist survival model,roulette wheel selection with limited candidates, and multi-point shuffle cross-over method are adapted. And pseudo object function, which is the combined form of object function and penalty function, is used to include constraints into fitness function. GA shows good results of weight reducing effect and convergency in optimal design of drilling machine.

• 천문학회보
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• 제44권2호
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• pp.39.1-39.1
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• 2019

We trace the cosmological origin of satellites around isolated dwarf galaxies using a very high resolution (12 pc/h) cosmological hydrodynamic zoom simulation. To realistically describe the formation and evolution of small-mass stellar satellites, our model includes a full baryonic physics treatment. We find that the mini-halos form objects resembling dwarf galaxies. The majority of their star forming gas is accreted after reionization, thus the survival of a mini-halo's gas to reionization is not an important factor. Instead, the key factor seems to be the ability for a mini-halo to cool its recently accreted gas, which is more efficient in more massive halos. Although the host galaxy is only a dwarf galaxy itself, we find that ram pressure is an efficient means by which accreted mini-halos lose their gas content, both by interacting with hot halo gas but also in direct collisions with the gas disk of the host. The satellites are also disrupted by the tidal forces near the center of the host galaxy. Compared to the disrupted satellites, surviving satellites are relatively more massive, but tend to infall later into the host galaxy, thus reducing the time they are subjected to destructive environmental mechanisms and dynamical friction.

• Educational Technology International
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• 제13권1호
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• pp.49-77
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• 2012

The development of mobile devices and network technology is changing the ways in which people communicate with one another. Mobile text message has emerged as one of the most frequently used form of communication, which also gave rise to various non-verbal texts such as emoticons. Nonetheless, the use of text messages has largely been denied in education because text messages often involve colloquial and non-verbal texts considered inappropriate or grammatically incorrect by the teacher. In efforts to provide a theoretical framework to better understand mobile e-text communication, this research compared the practical usages of non-verbal texts in the mobile e-learning environment. The study developed three types of text messages according to the degree of using non-verbal texts and their phraseology as instructors' messages, which were then distributed to 259 students via mobile text messaging. The perceptions of students were analyzed using a semantic differential scale and a questionnaire. The results showed clear differences in students' perceptions of non-verbal text and traditional text, and that optimally designed non-verbal texts turned out to encourage the students' interaction the most out of the three types of text messages. Following the discussion of the results, an expanded theoretical framework beyond Ong's concepts of orality and literacy is also suggested to understand the evolution of mobile e-text communication in education.

• 한국과학교육학회지
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• 제27권6호
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• pp.465-476
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• 2007

Whether and when naturalistic or supernaturalistic explanations of the origins of sun and earth, humans, life and species change with development was explored in a questionnaire and interviews with 32 first graders and 32 second graders, and in a questionnaire with 34 third graders, 32 sixth graders and 38 eighth graders. Participants were also asked about factors affecting their explanations in the questionnaires. Even the first and second graders could consistently provide supernaturalistic or naturalistic explanations on both the origins of sun and earth, and of humans. There was an age-related developmental shift from supernaturalistic to naturalistic explanation. As for origins of species, most of the first and second graders held the spontaneous generationist explanation, and after the third grade their views divided into evolutionist and creationist explanations. Students' explanations of species origins were established by the sixth grade through a transitional stage in the third grade. At the first and second grade levels, books and the children's own reasoning mainly influenced the views of origins, whereas parents and school were not perceived as being important. For the third graders and higher-grade levels, several factors, including parents and religion, were perceived as being important. These results show that explanations of origins start to develop earlier than or during the first grade, and are established by the sixth grade; moreover, the formation of these views is affected by several factors in addition to development.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1480-1489
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• 2024

Displacement cascade behaviors of Ti-6Al-4V alloys are investigated using molecular dynamics (MD) simulation. The embedded atom method (EAM) potential including Ti, Al and V elements is modified by adding Ziegler-Biersack-Littmark (ZBL) potential to describe the short-range interaction among different atoms. The time evolution of displacement cascades at the atomic scale is quantitatively evaluated with the energy of primary knock-on atom (PKA) ranging from 0.5 keV to 15 keV, and that for pure Ti is also computed as a comparison. The effects of temperature and incident direction of PKA are studied in detail. The results show that the temperature reduces the number of surviving Frenkel pairs (FPs), and the incident direction of PKA shows little correlation with them. Furthermore, the increasing temperature promotes the point defects to form clusters but reduces the number of defects due to the accelerated recombination of vacancies and interstitial atoms at relatively high temperature. The cluster fractions of interstitials and vacancies both increase with the PKA energy, whereas the increase of interstitial cluster is slightly larger due to their higher mobility. Compared to pure Ti, the presence of Al and V is beneficial to the formation of interstitial clusters and indirectly hinders the production of vacancy clusters.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1490-1500
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• 2024

Helium-induced defect nucleation and accumulation in polycrystalline W and W0.5 wt%ZrC (W0.5ZrC) were studied in-situ using the transmission electron microscopy (TEM) combined with 40 keV He⁺ irradiation at 800 and 1000℃ at the maximum damage level of 1 dpa. Radiation-induced dislocation loops were not observed in the current study. W0.5ZrC was found to be less susceptible to irradiation damage in terms of helium bubble formation and growth, especially at lower temperature (800 ℃) when vacancies were less mobile. The ZrC particles present in the W matrix pin the forming helium bubbles via interaction between C atom and neighbouring W atom at vacancies. This reduces the capability of helium to trap a vacancy which is required to form the bubble core and, as a consequence, delays, the bubble nucleation. At 1000 ℃, significant bubble growth occurred in both materials and all the present bubbles transitioned from spherical to faceted shape, whereas at 800 ℃, the faceted helium bubble population was dominated in W.