• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.15-22
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• 2013

Low-Temperature-cofired ceramics (LTCC) antenna packages have been extensively researched and utilized in recent years due to its excellent electrical properties and ease of implementing dense package integration topologies. This paper introduces some of the key research and development activities using LTCC packaging solutions for 60 GHz antennas at Samsung Electronics [1]. The LTCC 60 GHz antenna element topology is presented and its measured results are illustrated. However, despite its excellent performance, the high cost issues incurred with LTCC at millimeter wave (mmWave) frequencies for antenna packages remains one of the key impediments to mass market commercialization of mmWave antennas. To address this matter, for the first time to the author's best knowledge this paper alleviates the high cost of mmWave antenna packaging by devising a novel, broadband antenna package that is wholly based on low-cost, high volume FR4 Printed Circuit Board (PCB). The electrical properties of the FR4 substrate are first characterized to examine its feasibility at 60 GHz. Afterwards a compact multi-layer antenna package which exhibits more than 9 GHz measured bandwidth ($S_{11}{\leq}-10$ dB) from 57~66 GHz is devised. The measured normalized far-field radiation patterns and radiation efficiency are also presented and discussed.

• Communications for Statistical Applications and Methods
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• v.28 no.4
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• pp.393-410
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• 2021

The Korean Long-Term Care Insurance (K-LTCI) provides financial support for long-term care service to people who need various types of assistance with daily activities. As the number of elderly people in Korea is expected to increase in the future, the demand for long-term care insurance would also increase over time. Projection of future expenditure on K-LTCI depends on the number of beneficiaries within the grading system of K-LTCI based on the test scores of applicants. This study investigated the suitability of mixture distributions to the model K-LTCI score distribution using recent empirical data on K-LTCI, provided by the National Health Insurance Service (NHIS). Based on the developed mixture models, the number of beneficiaries in each grade and its variability under the current grading system were estimated by simulation. It was observed that a mixture model is suitable for K-LTCI score distribution and may prove useful in devising a funding plan for K-LTCI benefit payment and investigating the effects of any possible revision in the K-LTCI grading system.

• Geomechanics and Engineering
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• v.33 no.2
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• pp.155-165
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• 2023

Hurricane Katrina swept New Orleans, Louisiana, USA, in 2005, causing more than 1,000 fatalities and severe damage to the flood protection system. Recovery activities are complete, however, clarifying failure mechanisms and devising resilient and cost-effective retrofitting techniques for the flood protection system are still of utmost importance to enhance the general structural integrity of water retaining structures. This study presents extensive centrifuge test results to find various failure mechanisms and effective retrofitting techniques for a levee system. The result confirmed the rotational failure and translational failure mechanisms for the London Ave. Canal levee and 17^th St. Canal levee, respectively. In addition, it found that the floodwalls with fresh waterstop in their joints perform better than those with old/weathered waterstop by decreasing pore water pressure build-up in the levee. Structural caps placed on the top of the joints between I-walls could also prevent local failure by spreading the load to surrounding walls. At the same time, the self-sealing bentonite-sand mixture installed along the riverside of floodwalls could mitigate the failure of floodwalls by blocking the infiltration of seepage water into the gap formed between levee soils and floodwalls.

• Journal of Fashion Business
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• v.27 no.2
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• pp.108-123
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• 2023

Recent increase of eco-conscious trends and pleasure from Do It Yourself (DIY) activities have led to a surge in sales of package products bundling together clothing patterns and raw materials. However, a well-structured market system is yet to be established. We surveyed 460 women with sewing as a hobby who had purchased these DIY clothing pattern packages. The survey revealed that majority of respondents had their hobby for over five years. Choosing the right fabric to match clothing patterns presented a common challenge. Most participants owned a sewing machine and an overlocker, with price being the primary concern when purchasing a package. For guidance during the sewing process, participants preferred print materials featuring real-life images. Those with less sewing experience leaned towards video tutorials. Items of interest or those commonly created included blouses, shirts, and dresses. Desire for further learning in sewing and pattern-making was prominent, with a clear preference for online classes. Several strategies are recommended to enhance the appeal of DIY clothing package products, including broadening range of packages that incorporate fabric, offering supplementary educational resources to improve users' skills, implementing affordable pricing structures, supplying comprehensive creation guidelines, and making available design modification guides. These considerations could significantly boost customer satisfaction. This research intends to lay groundwork for understanding DIY clothing creation market, ultimately fostering production of highly desirable products. Insights of this study will prove instrumental in refining product development and devising effective marketing tactics, leading to a more rewarding consumer experience.

• Advances in nano research
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• v.15 no.6
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• pp.541-550
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• 2023

The escalating growth of industrial sectors has led to a pervasive global problem—oil pollution, particularly in industrial areas. The release of substantial volumes of oil and its by-products into the environment has resulted in extensive contamination. Multiple factors contribute to the entry of these substances into water bodies and soils, thereby inflicting irreparable consequences on ecosystems, natural resources, and human health. Consequently, it becomes imperative to comprehend the characteristics and behavior of oil pollution, anticipate its impacts, and develop effective mitigation strategies. Understanding this intricate issue requires considering the physicochemical properties of the environment, the interactions between oil and sediments, and biological factors such as evaporation and dissolution. Although the oil industry has brought about remarkable advancements, its activities have raised significant concerns regarding pollution from extraction and production processes. Oil-rich nations face a particularly challenging predicament of soil pollution caused by petroleum compounds. The areas surrounding oil exploration mines and refineries often endure contamination due to oil leakages from storage tanks and transmission lines resulting from deterioration and damage. Investigating the dispersion of such pollutants and devising methods to remediate petroleum-contaminated soil represent crucial and intricate issues within the realm of environmental geotechnics.

• International Journal of Advanced Culture Technology
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• v.11 no.4
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• pp.9-15
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• 2023

The outbreak of COVID-19 has significantly impacted various facets of individuals' lives, including perceptions, leisure activities, work-family balance, and overall life satisfaction. This study aims to explore the intricate relationships among changes in perceptions due to COVID-19, leisure activity satisfaction, work-family conflict, and life satisfaction of married working women. Employing path analysis, we examined a dataset of 1,973 married working women drawn from the 8th Korean Women and Families Panel Survey. The findings indicate that while changes in perception associated with COVID-19 did not directly affect leisure activity satisfaction and life satisfaction, they did significantly decrease work-family conflict, indirectly leading to heightened life satisfaction. Additionally, leisure activity satisfaction emerged as a mitigating factor for work-family conflict, contributing to enhanced life satisfaction. These results emphasize the importance of understanding the interplay between external factors, individual perceptions, and well-being, offering insights for devising tailored strategies. The study holds significance in guiding policies and interventions to enhance the quality of life for married working women in the context of evolving pandemic challenges.

• Journal of Science Education
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• v.41 no.3
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• pp.318-333
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• 2017

In this study, we analyzed activities in life science chapters of middle school 'science' textbooks for the 2009 revised Korea national curriculum and examined the difference between the analysis based on scientific practices and the analysis based on inquiry skills. As a results, there was a lot of inquiry skills in the order of 'reasoning', 'observing', 'classification' in the all of grade. In scientific practices, 'data analysis and interpretation' and 'constructing explanations and devising problem solving' were biased. This shows that life science inquiry activities in middle school 'science' textbooks are lacking in diversity in scientific practice elements as well as inquiry skills, and that the goals of the activities are limited. In addition, through the interrelationships between scientific inquiry skills and scientific practice elements, we examined contents relevance in the transition from inquiry function center to scientific practice, and compared with the results of inquiry activities in textbook, The results of this study were matched monotonously due to the tendency to basic inquiry-data interpretation / basic inquiry-explanation. This comes from results of the lack of diversity in activities presented in middle school 'science' textbooks. In this study, it is suggested that efforts should be made to include diverse scientific practice elements in the process of realizing 2015 revised Korea national curriculum from the simple and diversity-less inquiry activity through analyzing the textbooks of the 2009 revised Korea national curriculum.

• Journal of The Korean Association For Science Education
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• v.34 no.2
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• pp.187-195
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• 2014

In this study, we investigated the characteristics of lesson planning of pre-service secondary science teachers and the factors which influenced in their lesson planning. Thirteen pre-service secondary science teachers at a college of education in Seoul participated in this study. Teaching-learning materials such as lesson plans and handouts, and lesson planning journals written by the pre-service teachers were collected. Semi-structured interviews were also conducted to obtain information about their lesson planning activities. The analyses of the results revealed that most of the pre-service teachers did not systematically consider the national science curriculum and focused on planning one lesson only. Instructional objectives were not only considered as minor element in lesson planning, but also limited to cognitive domain. Devising teaching-learning strategies was found to be the starting point of the lesson planning. They accommodated constructivistic teaching-learning theory presented in their method courses through reflective evaluation of the experiences of learning in their secondary schools. The experiment activities that were presented in the textbooks were used themselves when they planned experiments as student activities, but other activities were planned depending on their personal experiences. Most pre-service teachers did not plan assessment because they could not recognize it as an element of lesson planning. These results may offer some implications in educating pre-service secondary science teachers on lesson planning.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.99-113
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• 2008

In order to protect Rescue 119 workers exposed on the spot from potential infection, this study identified their awareness and practices of infection control so that it could help preventing them from infection and also provide basic materials necessary for pre-hospital infection control. This study applied questionnaire survey to total 215 Rescue 119 workers at fire stations in Jeonbuk province, Jeonnam province and Gwangju city from July 14 to Sept. 14, 2006 for the benefit of data collection. The questionnaire about possible associations between awareness and practices of infection control consisted of total 46 times across 6 categories such as washing hands during emergency activities ; fluid therapy and injection ; respirator maintenance; individual hygienics ; disinfectant supplies and equipments maintenance ; and control of infectious wastes. And collected data were processed using SPSS statistic program to analyze frequency and percentage, mean and standard deviation, Pearson's correlation coefficient, t-test and one-way ANOVA. As a result, this study came to the following conclusions : In terms of awareness about infection control, our respondents showed highest awareness about infectious waste control, and also showed highest level of practices in washing hands during emergency activities. Throughout all domains, awareness means were higher than practice means. In particular, infectious waste control was the domain of significant differences between awareness and practices. In terms of associations between awareness and individual characteristics, it was found that female rescue worker group and hospital/general hospital career group (before joining the Rescue 119) showed significantly higher awareness on statistic level. In regard to associations between individual characteristics and practices, it was found that female rescue worker group showed higher level of practices than male group on statistic level. This study also analyzed correlations between rescue workers' awareness and practice of infection control. As a result, it was found that the higher awareness was in correlations with the higher practices across all 6 domains including washing hands. In addition, the higher awareness of a questionnaire item was in significantly positive correlations with the higher practice of other items. However, our respondents showed high awareness about anti-infection, but low practices in reality. This indicates necessity of devising possible solutions to improve the practices as much as awareness. Especially, it was noted that major reasons for insufficient practices of infection control guideline come from unhabituated practices and lack of supports for infection-preventing supplies and protective device (mask, etc). Hence, it is necessary to provide more infection-preventing supplies for local rescue workers sufficiently, in parallel with steady habituation of infection control. Furthermore, it is required to manage and study infection control policies even at pre-hospital step in efforts for effective infection control, education and activities.

• Ocean and Polar Research
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• v.28 no.2
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• pp.163-173
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• 2006

The so called Antarctic Treaty System, started from the Antarctic Treaty in 1959, has gradually been enlarged into the concept of an international environmental regime, which has been included in not a few international institutions, treaties, conventions, and international non-governmental organizations (INGO). This kind of movement, as in the role of an international environmental regime, has recently been highlighted in the Protocol on Environmental Protection to the Antarctic Treaty. This Protocol is taking appropriate measures as an international environmental regime in regulating its member nations by enforcing principles in protecting Antarctic resources and environment, regulating member nations' Antarctic activities, establishing norms in the adoption of international and domestic laws, and devising regulations for deciding administrative actions through the member nations' collective decision-making procedures. h this context, this paper is to test a few questions; firstly, how the Antarctic Treaty System can be related with the role of international environmental regime; secondly, how the theories of international environmental regime, such as the hegemony theory, rational choice theory, and international morality theory, can be tested in the role of Antarctic Treaty System as an international environmental regime. Finally, this paper provides a solution for the future problems of the Antarctic Treaty System as an international environmental regime regarding the regime's principle (conflict between the environmental principle and the right of nation-state), norms and regulations (the conflict between the developed and underdeveloped nations in terms of the concept of 'common but differentiated environmental responsibility'), cooperation directions (the leadership problems between hegemonic nation and multilateral leading groups), and management methods (cooperation and arrangement problems among expert institutions, observer groups, and INGO).