• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.400.1-400.1
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• 2016

Interfacial engineering approaches as an efficient strategy for improving the power conversion efficiencies (PCEs) of inverted polymer solar cells (iPSCs) has attracted considerable attention. Recently, polymer surface modifiers, such as poly(ethyleneimine) (PEI) and polyethylenimine ethoxylated (PEIE), were introduced to produce low WF electrodes and were reported to have good electron selectivity for inverted polymer solar cells (iPSCs) without an n-type metal oxide layer. To obtain more efficient solar cells, quantum dots (QDs) are used as effective sensitizers across a broad spectral range from visible to near IR. Additionally, they have the ability to efficiently generate multiple excitons from a single photon via a process called carrier multiplication (CM) or multiple exciton generation (MEG). However, in general, it is very difficult to prepare a bilayer structure with an organic layer and a QD interlayer through a solution process, because most solvents can dissolve and destroy the organic layer and QD interlayer. To present a more effective strategy for surpassing the limitations of traditional methods, we studied and fabricated the highly efficient iPSCs with mono-layered QDs as an effective multi-functional layer, to enhance the quantum yield caused by various effects of QDs monolayer. The mono-layered QDs play the multi-functional role as surface modifier, sub-photosensitizer and electron transport layer. Using this effective approach, we achieve the highest conversion efficiency of ~10.3% resulting from improved interfacial properties and efficient charge transfer, which is verified by various analysis tools.

• Journal of the Korean Society of Costume
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• v.65 no.2
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• pp.33-47
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• 2015

The purpose of this study is to understand the ideas of characteristic of convergence design related to slow fashion design. Convergence design in digital stage can be defined as a social phenomenon which different function of product move toward one direction for greater efficiency. Slow fashion is based on the Slow Movement. (This is a movement with similar principles to the Slow Food Movement, as it promotes an alternative mass production, such as fast fashion.) The aims of this research are to study slow fashion that has appeared in the fashion industry through various approaches for convergence designs, and to find the possibility of use for slow fashion. The research method consisted of carrying out case studies and analyzing literatures and proceeding cases. The characteristics of convergence designs are classified into technical convergence, emotion-oriented convergence and complex convergence. Technical convergence has an effect on slow fashion as a multi-functional design. Second, emotion-oriented convergence affects social-cultural design. Slow fashion related to a complex convergence design reveals emotion-oriented deign. Slow fashion is related to convergence design is to expect contribute to provide a good source for the future fashion industry and fashion market.

• Korean Journal of Biological Psychiatry
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• v.9 no.1
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• pp.15-24
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• 2002

Even though alcoholism is a multi-factorial psychiatric disorder, it is reasonable to suppose that genetic factors play a substantial role in the manifestation of this disorder. Because alcohol is the reinforcing substance which manifests its effects through activation of the mesolimbic dopaminergic reward pathway of the brain, the gene encoding dopamine receptor subtypes can be a major natural candidate gene. Since 1990, many association studies have identified strong evidence implicating the dopamine D2 receptor(DRD2) gene in alcoholism, specifically TaqI A minor(A1) allele. Association studies have also been conducted on other dopamine receptor(DRD3 & DRD4) polymorphisms but the results have yet to be confirmed. Through a number of other approaches, each dopamine receptor gene has been investigated in association with different phenotypes in alcoholism, but further researches will be needed. In conclusion, studies in the past decade have shown that the TaqI A1 allele of the DRD2 gene is associated with alcoholism in various subject groups. Other dopamine receptor genes have since been added to the list but yet to be identified. Thus, the knowledge of these genes and their functional significance will enhance the understanding of the underlying biological mechanisms of alcoholism. Furthermore, it could lead to more helpful prevention and treatment approaches to alcoholism.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.2
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• pp.126-130
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• 2010

This paper presents the conceptual design of a multi-rotor unmanned aerial vehicle (UAV) based on an axiomatic design. In most aerial vehicle design approaches, design configurations are affected by past and current design tendencies as well as an engineer's preferences. In order to design a systematic design framework and provide fruitful design configurations for a new type of rotorcraft, the axiomatic design theory is applied to the conceptual design process. Axiomatic design is a design methodology of a system that uses two design axioms by applying matrix methods to systematically analyze the transformation of customer needs into functional requirements (FRs), design parameters (DPs), and process variables. This paper deals with two conceptual rotary wing UAV designs, and the evaluations of tri-rotor and quad-rotor UAVs with proposed axiomatic approach. In this design methodology, design configurations are mainly affected by the selection of FRs, constraints, and DPs.

• Advanced Composite Materials
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• v.18 no.2
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• pp.153-166
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• 2009

A matrix method for evaluating effective electro-magneto-thermo-elastic properties of a generally anisotropic multilayered composite is presented. Physical variables are categorized into two groups: one that satisfies the continuity across the interface between layers and another that satisfies an average inter-layer compatibility (which is also exact). The coupled electro-magneto-thermo-elastic constitutive equation is accordingly reassembled into submatrices, which leads to the derivation of concise and exact matrix expressions for effective properties of a multilayered composite having the coupled physical effects. Comparing the results for a purely elastic multiplayer with those from other theoretical approaches validates the developed method. Examples are given for a PZT-graphite/epoxy composite and a $BaTiO_3-CoFe_2O_4$ multiplayer which exhibit piezo-thermoelastic and magnetoelectric properties, respectively. The result shows how a strong magnetoelectric effect can be achieved by combining piezoelectric and piezomagnetic materials in a multilayered structure. The magnetoelectric coefficient of the $BaTiO_3-CoFe_2O_4$ multiplayer is compared with those for fibrous and particulate composites fabricated with the same constituents.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.117-120
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• 2005

A Digital Broadcasting Satellite (DBS) receiver converts digital A/V streams received from a satellite to analog NTSC A,/V signals in real-time. Multi-tasking is an efficient way to improve the utilization of the processor core in real-time applications. In this paper, we propose a hybrid approach with a balanced trade-off between hardware kernel and multi-tasking programming to increase a system throughput. First, the schedulability of the critical hard real-time tass in the DBS receiver is verified by using a simple feasibility test. Then. several soft real-time tasks are thoughtfully programmed to satisfy functional requirements of the system.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.280-280
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• 2013

In green plants, energy generation is accomplished through light-harvesting photosystem, which utilize abundant visible light and multi-stepwise redox reaction to oxidize water and reduce NADP+, transferring electrons efficiently with active cofactors1. Inspired by natural photosynthesis, artificial solar water-splitting devices are being designed variously. However, the several approaches involving immobilization2, conjugation3, and surface modification4 still have limitations. We have made artificial photosynthesis templates by self-assembling tyrosine-based peptide to mimick photosystem II. Porphyrin sensitizer absorbing blue light strongly was conjugated with the templates and they were hybridized with cobalt oxide through the reduction of cobalt ions in an aqueous solution. The formation of hybrid templates was characterized using TEM, and their water oxidation performance was measured by fluorescence oxygen probe. Our results suggest that the bio-templated assembly of functional compounds has a great potential for artificial photosynthesis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.245-258
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• 2008

We describe here how we can use microfluidic technologies for fabricating functional materials that could be potentially utilized in cosmetics; these include void structures, functional particulate materials, shell materials, and multi-layered colloids. We can obtain these functional materials as microfluidic approaches provide precise control over both outer dimensions and inner morphology of emulsion drops in picoliter-volume scales with high throughput. We have confirmed that this technique has a great potential to fabricate novel particles and capsules with a variety of chemical compositions as well as higher orders of layers. This microfluidic approach will allow us to develop a lot of new techniques that are useful for a variety of applications, including delivery systems, chemical separations, bio-sensing, actuators, and so on. We do believe that these new techniques will help cosmetic industry not only give rise advanced functional materials and systems but also widen its product categories.

• Journal of Broadcast Engineering
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• v.12 no.1 s.34
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• pp.53-60
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• 2007

A Digital Broadcasting Satellite (DBS) receiver converts digital A/V streams received from a satellite to analog NTSC A/V signals in real-time. Multi-tasking is an efficient way to improve the utilization of the processor core in real-time applications. In this paper, we propose a hybrid approach with a balanced trade-off between hardware kernel and multi-tasking programming to increase a system throughput. First, the schedulability of the critical hard real-time tasks in the DBS receiver is verified by using a simple feasibility test. Then, several soft real-time tasks are thoughtfully programmed to satisfy functional requirements of the system.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.5
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• pp.13-25
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• 2008

Although competitions for large parks are increasing rapidly across the world, theoretical research and critiques of these competitions are as yet insufficient. The 'International Design Competition for Central Open Space in Multi-functional Administrative City, Korea', a representative competition for large park design, can be a significant resource for examining the contemporary design strategies that go into the design of a large park. In this study, the authors make a framework for analysis by looking at the competition's design guidelines and literatures on 'large parks', and by then analyzing the ten finalists. Four questions that were derived from the framework were: 'what are the approaches to large parks?', 'what is the process of design?', 'what is the sustainability of the park?', and 'what are the relations between city and park?' The results of the study are as follows. First, the design concepts for large parks are primarily site-specific. It is particularly important in ensuring the identity of the large park. Second, it is difficult to find design proposals which satisfy the four main questions sufficiently, and works submitted tend to be visual-oriented, form-oriented, and results-centered. Third, the notion of 'sustainability' in large parks is a comprehensive one which includes various aspects such as ecology, finance, programming, and community. However, the notion remains ambiguous, and plans for operation and management are not concretely proposed. Finally, design proposals for large parks accompany positive relations with the city. Especially, 'productive parks' and 'city self-sufficiency' are very important demands in regards to large parks.