• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.195.2-195.2
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.57.1-57.1
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• 2018

Reionisation in the early Universe is likely driven by dwarf galaxies. Using cosmological RHD simulations, we study star formation and the escape of Lyman continuum (LyC) photons from mini-haloes with Mhalo<108Msun. We find that feedback reduces star formation very efficiently in mini-haloes, resulting in the stellar mass consistent with the empirical stellar mass-to-halo mass relation derived in the local Universe. Because star formation is stochastic and dominated by a few gas clumps, the escape fraction in mini-haloes is generally determined by photo-ionization, rather than supernova explosions. We find that the photon number-weighted mean escape fraction in mini-haloes is higher (20-40%) than that in atomic-cooling haloes. Despite their high escape fractions, LyC photons from mini-haloes are of minor importance for reionization due to inefficient star formation. We confirm previous claims that stars in atomic-cooling haloes with masses $10^8M_{sun}$$10^{11}M_{sun}$ are likely to be the most important source of reionization.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.36.1-36.1
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• 2018

Understanding the origin of strong galactic outflows and the suppression of star formation in dwarf galaxies is a key problem in galaxy formation. Using a set of radiation-hydrodynamic simulations of an isolated dwarf galaxy, we show that the momentum transferred from resonantly scattered Lyman-alpha(LyA) photons can suppress star formation by a factor of two in metal-poor galaxies by regulating the dynamics of star-forming clouds before the onset of supernova explosions (SNe). This is possible because each LyA photon resonantly scatters and imparts ~10-300 times greater momentum than in the single scattering limit. Consequently, the number of star clusters predicted in the simulations is reduced by a factor of ~5, compared to the model without the early feedback. More importantly, we find that galactic outflows become weaker in the presence of strong LyA radiation feedback, as star formation and associated SNe become less bursty. We also examine a model in which radiation field is arbitrarily enhanced by a factor of up to 10, and reach the same conclusion. The typical mass-loading factors in our metal-poor dwarf system are estimated to be ~5-10 near the mid-plane, while it is reduced to ~1 at larger radii.

• Safety and Health at Work
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• v.10 no.1
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• pp.21-29
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• 2019

Background: Promoting healthy lifestyles at work should complement workplace safety programs. This study systematically investigates current states of occupational health and safety (OHS) policy as well as practice in the European Union (EU). Methods: OHS policies of EU member states were categorized as either prevention or health promotion provisions using a manifest content analysis. Policy rankings were then created for each prevention and promotion. Rankings compared eight indicators from the European Survey of Enterprises on New and Emerging Risks-2 data on prevention and promotion practices for each member state using Chi-square and probit regression analyses. Results: Overall, 73.1% of EU establishments take preventive measures against direct physical harm, and about 35.4% take measures to prevent psychosocial risks. Merely 29.5% have measures to promote health. Weak and inconsistent links between OHS policy and practice indicators were identified. Conclusion: National OHS policies evidently concentrate on prevention while compliance with health and safety practices is relatively low. Psychosocial risks are often addressed in national policy but not implemented by institutions. Current risk assessment methods are outdated and often lack psychosocial indicators. Health promotion at work is rare in policy and practice, and its interpretation remains preventive. Member states need to adopt policies that actively improve health and well-being at the workplace.

• Journal of the Korean Society of Costume
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• v.61 no.9
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• pp.84-96
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• 2011

This paper investigates the formative features and the historical meaning of the Korean dress collection held in the Museum of Archaeology and Anthropology in Cambridge. The Museum holds a total of eleven items of koran dresses that were donated by two anthropologists in the first half of the twentieth century. Male dresses consist of a white cotton jacket (Jeogori), a under-vest (Deungbaeja) made of light wisteria rings, a headband (Manggeon) made of horsehair, a broad brimmed top hat (Gat) made of black horsehair gauze, an oilskin cover (Galmo) drawn over the hat in wet weather, and a hemispherical hat box (Gatjib). Female dresses comprise a pink silk jacket (Jeogori), a blue silk skirt (Chima) with pleats, a pair of woman's white cotton trousers (Sokgot), a black silk cap (Jobawi) decorated with pink tassels and imitation pearls, and a pair of green and magenta silk shoes (Danghye) with leather soles and metal rivets. Theses Korean dresses show what the western anthropologists had interests in. When collectors collect the folk objects, they thought much of the specificity of shape and material, the esthetic appreciation, and the representation of daily life. In terms of the value as the historical materials in the history of Korean dress, the under-vest of wisteria, the hat box, and the female dresses are worth paying attention to. The under-vest is one that was produced in earlier time among the remaining under-vests. The hat box represents that the hat belonged to the merchant classes. The female dress items show daily dresses worn by women of higher classes of the society in the 1920s.

• Advances in Computational Design
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• v.3 no.4
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• pp.385-404
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• 2018

The study investigated an area of sustainable structural design that is often overlooked in practical engineering applications. Specifically, a novel method to simultaneously optimise the cost and embodied carbon performance of steel building structures was explored in this paper. To achieve this, a parametric design model was developed to analyse code compliant structural configurations based on project specific constraints and rigorous testing of various steel beam sections, floor construction typologies (precast or composite) and column layouts that could not be performed manually by engineering practitioners. Detailed objective functions were embedded in the model to compute the cost and life cycle carbon emissions of the different material types used in the structure. Results from a comparative numerical analysis of a real case study illustrated that the proposed optimisation approach could guide structural engineers towards areas of the solution space with realistic design configurations, enabling them to effectively evaluate trade-offs between cost and carbon performance. This significant contribution implied that the optimisation model could reduce the time required for the design and analysis of multiple structural configurations especially during the early stages of a project. Overall, the paper suggested that the deployment of automated design procedures can enhance the quality as well as the efficiency of the optimisation analysis.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.70.3-70
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• 1998

• 순환기질환의공학회:학술대회논문집
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• 2006.10a
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• pp.34-35
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• 2006

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.444-447
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• 2003

A flat panel field sequential 3D display can be made by illuminating a ferroelectric liquid crystal display with scanning illumination passed through a transparent slab embossed with a grating. The concept is expected to enable wide fields of view, sharp discrimination between views, little blurring at depth, and no repetition of views.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.2
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• pp.219-236
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• 2022

The Oxford area is one of the major innovative regions of the world. The innovative characteristics of the area, however, have not been well exposed to the academic communities of the world and Korea. In fact, the area was a base of breading the Cambridge area and has also been playing important roles in creating the major British high-technology region, called "Golden Triangle," composed of Oxford, Cambridge and London. This paper investigates the process of growing innovativeness of the Oxford area and sheds more lights on the birth, growth and key actors of the area's Regional Innovation Systems(RISs). For this research, the author reviewed the literature related to the RISs, and gathered data based on the Internet, statistical data sources, interviews with local scholars and practitioners.