• Current Optics and Photonics
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• 제8권1호
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• pp.16-29
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• 2024

This paper presents a comprehensive review of metasurface technology, focusing on its significant role in extraordinary flat optic functionalities. Traditional optical components, though optimized, are bulky and less congruent with modern integrated electromagnetic and photonic systems. Metasurfaces, recognized as the 2D counterparts of bulk metamaterials, offer solutions with their planar, ultra-thin, and lightweight structures. Their meta-atoms are adept at introducing abrupt shifts in optical properties, paving the way for high-precision light manipulation. By introducing the key design principles of these meta-atoms, such as the magnetic dipole and Pancharatnam-Berry phase, various applications in wavefront shaping and beam forming with simple amplitude/phase manipulation and advanced applications including retroreflectors, Janus metasurfaces, multiplexing of optical wavefronts, data encryption, and metasurfaces for quantum applications are reviewed.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.286-298
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• 2024

The rapid advancement of drone technology has significantly altered the landscape of modern warfare, presenting both opportunities and challenges for military forces worldwide. As drones become increasingly sophisticated, capable of performing complex missions such as reconnaissance, surveillance, and precision strikes, the development of effective air defense systems has become a critical priority. This study examines the current state of drone and air defense technologies, analyzing their impact on military strategies, tactics, and the future battlefield environment. By exploring the patterns of technological evolution, the limitations of existing air defense systems, and the potential consequences of drone proliferation, this research highlights the need for adaptive, innovative approaches to counter emerging threats. The findings underscore the importance of investing in advanced detection and interception capabilities, developing comprehensive counter-drone doctrines, and fostering international cooperation to address the ethical and legal challenges posed by the military use of drones. As the competition between drone and air defense technologies continues to intensify, policymakers and military leaders must proactively engage in shaping the future of warfare to ensure national security and stability in an increasingly complex world.

• Journal of Species Research
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• 제10권3호
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• pp.246-254
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• 2021

Subalpine and alpine ecosystems are especially vulnerable to temperature increases. Betula ermanii Cham. (Betulaceae) is a dominant broad-leaved tree species in the subalpine zone and is designated as a 'Climate-sensitive Biological Indicator Species' in South Korea. This study aimed to predict the potential distribution of B. ermanii under current and future climate conditions in South Korea using the MaxEnt model. The species distribution models showed an excellent fit (AUC=0.99). Among the climatic variables, the most critical factors shaping B. ermanii distribution were identified as the maximum temperature of warmest month (Bio5; 64.8%) and annual mean temperature (Bio1; 20.3%). Current potential habitats were predicted in the Baekdudaegan mountain range and Mt. Hallasan, and the area of suitable habitat was 1531.52 km², covering 1.57% of the Korean Peninsula. With global warming, future climate scenarios have predicted a decrease in the suitable habitats for B. ermanii. Under RCP8.5-2070s, in particular, habitat with high potential was predicted only in several small areas in Gangwon-do, and the total area suitable for the species decreased by up to 97.3% compared to the current range. We conclude that the dominant factor affecting the distribution of B. ermanii is temperature and that future temperature rises will increase the vulnerability of this species.

• 한국시스템다이내믹스연구
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• 제8권2호
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• pp.83-114
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• 2007

The Korean defense industry was brought up in the government policy since 1970's. The important parts of defense industrial technologies have not been developed, and usually introduced from overseas. Moreover, the development of advanced technologies was not actively stimulated or pursued, consequently shaping the current structure of the defense industry which lacks global competitiveness due to the dearth of high technologies necessary for high-technology weapons. This research analyzes the systems of the Korean defense industry through a systems thinking approach in order to understand the whole mechanism and to find ways to improve the defense industry. Finding some leverages is the main purpose of systems thinking, that yields desirable results with a little effort. The three policy leverages are: (1) the policy for timely fielding; (2) the R&D investment for development and production of domestic high-technology weapons; and (3) the policy measures for exports. The research findings will contribute to the invigorating and developing the Korean defense industry by providing policy-makers and acquisition practitioners with systematic understanding and insight into the dynamics of the defense industry for them to make and execute efficient policies taking into account the Korean overall defense industry.

• 영어어문교육
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• 제18권1호
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• pp.217-235
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• 2012

The purpose of this study was to identify the perceptual learning style preferences of 97 Korean EFL students in middle school. Furthermore, it examined if students' learning styles varied in terms of gender and grade level. Data was collected by using Reid's (1987) PLSPQ and a personal background questionnaire and was analyzed by using descriptive statistics, MANOVA, ANOVA, and t-test. The results revealed that subjects had all six major learning styles but among them, auditory, group, and visual styles were the most preferred by them. The results found in this study, presented that Korean EFL middle school students favored learning English through listening, reading and working in groups and that younger students preferred learning through physical involvement and practicum. The findings of this study provide a number of useful insights for EFL and ESL educators and instructors in Korea. The current study suggests that a great number of variables such as culture, learning situation of the target country, age, and grade level can all play important roles in shaping the learning preferences and the learning styles of students. Considering these variables and promoting a curriculum that is interesting, appealing and successful may help maximize student L2 learning.

• 한국세라믹학회지
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• 제55권6호
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• pp.527-555
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• 2018

High-temperature thermal insulation materials challenge extensive oxide candidates such as porus $SiO_2$, $Al_2O_3$, yttria-stabilized zirconia, and mullite, due to the needs of good mechanical, thermal, and chemical reliabilities at high temperatures simultaneously. Recently, porous rare earth (RE) silicates have been revealed to be excellent thermal insulators in harsh environments. These materials display attractive properties, including high porosity, moderately high compressive strength, low processing shrinkage (near-net-shaping), and very low thermal conductivity. The current critical challenge is to balance the excellent thermal insulation property (extremely high porosity) with their good mechanical properties, especially at high temperatures. Herein, we review the recent developments in processing techniques to achieve extremely high porosity and multiscale strengthening strategy, including solid solution strengthening and fiber reinforcement methods, for enhancing the mechanical properties of porous RE silicate ceramics. Highly porous RE silicates are highlighted as emerging high-temperature thermal insulators for extreme environments.

• 복식
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• 제50권
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• pp.51-68
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• 2000

This study is intended to examine the common features of costume images in science-fiction (SF) movies that deal with current socio-cultural situations by examining their themes and tones about the future it can be generally concluded that costume images of SF movies are divided into two patterns : one inheriting traditional styles constructed on linear progress and the other based on dismantiling the tradition. this analysis is made through the research of actual cinematic contexts on the common features of multiple styles shaping the two patterns of costume images. The results can be summarized as the following: The former is related with the future built up on the basis of belief in reasonal progress rooted in the Enlightenment reasonable plan for ideal social order and strong faith in uniformity. So It shows functional uniformity disregarding wasteful competitiveness in consumption and luxuriousness and clothing that has the aesthetic value of purity without emphasizing human body or sensuality are presented. On the other hand SF movies which show the uncertain costume image as the meaning of dismantling of tradition take up a rather critical view of assumption that society can move toward utopian future as it searches future images in the notion of hetero-topia by emphasizing pluralism consequently as for clothing diversity and uncertainty in post-modern style are presented destroying modernistic dichotomy and the assumption of Utopian clothing made in the notion of modern progressivism.

• 한국과학교육학회지
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• 제31권3호
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• pp.455-474
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• 2011

The purpose of this study is to explore the ways in which scientists reflect on the scientific practices, based on the premise that reflection is one of key elements for shaping scientific identities. This paper specifically considers scientists' reflections as the processes in which their senses of ethical issues and the value of science are articulated. To do so, the study developed a narrative inquiry for exploring the value of scientists' stories. Fourteen professional scientists' stories were collected in the context of the stem cell research, in ways that foreground their reflections on current scientific practices and the surrounding socio-cultural conditions. As for ethical issues, scientists' stories were analysed in terms of four claims regarding the themes of bioethics, integrity, scientific issues and communication. Furthermore, scientists' reflections on the value of science were analysed in relation to the elements of nature of science. Based on the results, discussion focused on the value of science stories as an instrument with which to guide students into the enculturation in the practices of scientific culture.

• 한국군사과학기술학회지
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• 제23권2호
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• pp.106-114
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• 2020

NCW which is shaping favorable conditions with obtaining initiative through superiority in C2 and information sharing is critical to the result of the war in a modern warfare. An important requirement to attain superiority through an effective networking in a war-environment is to apply QoS to ensure priority in supporting critical mission and services. In order to obtain an effective NCOE through JCS-led QoS support, standard doucments have been reviewed and analyzed to understand the current level of technology and development. In addition, QoS-related policy documents which is currently being applied by the ROK armed forces have been analyzed to substantiated the JCS-led QoS model and propose the directions of development and enhancement required in the realm of technology, policy and system.

• East Asian Economic Review
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• 제24권1호
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• pp.3-30
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• 2020

This paper analyzes how the current Global Value Chain (GVC) of East Asia has been established, and attempts to project the future trajectory of GVC under New Normal in the global trading system. For this purpose, the framework of Ideology-Technology-Institution nexus is presented with focus on the dynamics of interplay between ideology and technology, duly recognizing the dual-aspect of technology- a platform for business and also for national defense. The paper analyzes how the Information and Communication Technology (ICT) of the 1990s played a role of "facilitator" in shaping the GVC of East Asia, where China plays 'factory for final assembly' and the US plays 'the largest consumer'. Under New Normal, digital technology is likely to play the opposite role of "disrupting" the GVC of East Asia, unlike ICT. The paper explores the mechanism behind this great disruption. What is driving New Normal is the US-China power competition, seeking for dominance in East Asia and beyond. This paper argues that New Normal is not temporary shock, but will last for some time. Under this presumption, the paper presents three scenarios for the future trajectory of GVC in East Asia.