• International Journal of Highway Engineering
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• v.15 no.5
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• pp.65-73
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• 2013

PURPOSES : This study is to suggest future development direction and application of environmental noise barriers as multi-functional soundproof wall. METHODS : Based on the literature review, case study and patent search, research and patent trend were investigated. Patent search was conducted by Patent searching tools, 'Focust'. RESULTS : As environmental noise barriers, Vegetative soundproof wall, photovoltaic soundproof wall, and air-pollution reduction soundproof wall were investigated. First of all, In Korea, Vegetative soundproof wall is being developed mostly as soundproof wall that has vegetation foundation inside, to meet the domestic condition with 23 patent applications. Second, Photovoltaic soundproof wall is being developed mainly with efficiency of photovoltaic system rather than soundproofing. And it is limited to one generation solar cell technology, although Solar cell technology is developing at a rapid pace. On the other hand, for reducing air-pollutant by soundproof wall, a variety of methods are being suggested (filtration, adsorption, and photocatalytic oxidation), and one of them, adsorption are applied for developing air pollution reduction soundproof wall in Korea. CONCLUSIONS: The above soundproof wall is not simple structure, but road facility applied fusion technique. Therefore, as one system, it is difficult to harmonize due to various considerations for design factor. However, if it's possible that a benefits of one system apply to another system, Synergy effect may be created. In the foreseeable future, soundproof wall may be considered as a road system using fusion technique rather than just functional facility. Therefore, substantial studies for applying multi-functional soundproof wall on the road are needed for the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.824-828
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• 2000

As production cycle has become more and more shorter, the demand of rapid prototyping technology has increased largely. There are many methods for rapid prototyping technology, such as SLA. SLS, FDM. INK JET, LOM and so on. Of all methods, SLA has been most widely used for fabricating precision parts. But products manufactured by this method have limitation of single color and single material. So the principal purpose of this study is to overcome the limit of single color product. If the internal structure of manufactured product is visible with multi-color characteristic, it is possible to check easily the designed model with reality. In order to give multi-color characteristic to the product, photocurable resin mixed with pigment is used in this study. First, transparency of photocurable resin without pigment is evaluated, and then color characteristic and curing characteristic of the mixture is evaluated changing mixing ratio. Through the basic experiments, it becomes possible to fabricate multi-color 3D prototype without assembly.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.194-202
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• 2005

The objective of this paper is to develop a multi-functional hotwire cutting system (MHC) using EPS-foam block or plate as the working material. Because the MHC apparatus employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and a turntable, it allows the easy fabrication of various 3D shapes, such as (1) an axisymmetric shape or a sweeping cross-sectioned pillar shape using the hot-strip in the form of sweeping surface and EPS foam block on the turntable, (2) a polyhedral complex shape using the hotwire and EPS foam block on the turntable, and (3) a ruled surface approximated freeform shape using the hotwire and EPS foam plate. In order to examine the applicability of the developed MHC apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were fabricated on the apparatus.

• Journal of Integrative Natural Science
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• v.2 no.4
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• pp.252-264
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• 2009

Lithographic data obtained from PHS(polyhydroxy styrene) having various functionalities were investigated by using a photoacid generator based on diazo and onium type. Chemically amplified photoresist based on the KrF type photoresist was developed by using a photoacid generator and multi-functional resin. Thermal stability for the photoacid generator showed that the increase of loading amount of photoacid generator resulted in the decrease of glass transintion temperature (Tg). The photoacid generators having methyl, ethyl, or propyl group in their cationic structure produced T-top structure in pattern profile due to the effect of acid diffusion during the generation of acid in the resist. The increase of carbon chain length in the anionic structure of photoacid generators resulted in lower pattern resolution due to the interruption of acid diffusion.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.50-56
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• 2010

Polyethyleneterephthalate (PET) film is widely used in various industrial fields such as mobile phone, display pannel, notebook etc. Recently PET film attached on indium tin oxide (ITO) surface has a role of high pencil hardness, high refractive index etc. So we synthesized two types of multi-functional monomer which are epoxy modifed acrylate and unmodified acrylate type using recyclable resource like phloroglucinol, derived from trinitrotoluene. We studied the effect of multi-functional monomer's chemical structure on the various properties such as refractive index, optical transmittance, and pencil hardness. We characterized synthesized multi-functional monomer by qualitative analysis through H NMR. We observed that pencil hardness of 1,3,5-triepoxide benzene and 1,3,5-triacrylate benzene they have the range of 2~3 H at high UV dosage of 300 mW. Refractive index appeared the value of 1.54~1.57. Transmittance of all multi-functional monomers has more than 93%.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.357-362
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• 2020

The TMFT, a sub-system of TINC, provides voice calls, data transmission and reception, and multimedia services to individual users. At the time of development in 2011, the power circuit of the TMFT was designed to electrical power supply to each device via a charger IC. However, the newly improved power supply circuit allows power to be supplied to each device through the PMIC without configuring the charger IC separately. In this paper, the power circuit design structure of TMFT applied in the development stage and the improved power circuit design structure were compared. And we verified through experiments whether the improved power circuit can be applied to TMFT. The experimental method was verified by directly comparing the current consumption test, charge time comparison test, and rising temperature test during charging each of before and after improvement terminals.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.562-584
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• 2004

This paper intends to identify the structure of homogeneous regions and functional regions in Seoul based on B.J.L. Berry's ‘general field theory of spatial behavior’. The structure of homogeneous regions by using socio-economic variables can explain how the structural elements of the city are arranged. It can be ssid that Seoul has shifted towards more complicated and differentiated features in terms of homogeneous regions. The different patterns are found between the northern part to Han River where old torn areas are located and the southern part to Han River where newly urbanized areas are located. Usually, the concentric pattern and the sectoral pattern coexist, which is enhanced moving from CBD to the outskirt area. The distribution of different social classes shows irregular pattern similar to the variation of living environment. The social gap is expected to be more widening between new towns and old towns. The analysis of spatial movement pattern shows no clear hierarchical order because of current shifts towards both multi-nuclear pattern and spatial dispersion. The functional regions show duplicated structure overlapping their boundaries each other. The ‘general field theory of spatial behavior’ strongly suggests that spatial interactions among sub-areas in the city are differentiated from the basic characteristics and function of each sub-area. The attributes of homogeneous regions and functional regions are interrelated in the characteristics of isomorphic nature.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1523-1526
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• 2012

In this work, we prepared activated multi-walled carbon nanotubes/polyacrylonitrile (A-MWCNTs/C) composites by film casting and activation method. Electrochemical properties of the composites were investigated in terms of serving as MWCNTs-based electrode materials for electric double layer capacitors (EDLCs). As a result, the A-MWCNTs/C composites had much higher BET specific surface area, and pore volume, and lower volume ratio of micropores than those of pristine MWCNTs/PAN ones. Furthermore, some functional groups were added on the surface of the A-MWCNTs/C composites. The specific capacitance of the A-MWCNTs/C composites was more than 4.5 times that of the pristine ones at 0.1 V discharging voltage owing to the changes of the structure and surface characteristics of the MWCNTs by activation process.

• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.47-52
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• 2007

This paper presents the design of a submerged breakwater, which functions as an eco-structure in a marine environment. Newly patented blocks were used in the submerged breakwater to both make it stable and provide an inhabitable space for fish. To investigate the wave transmission of the proposed submerged breakwater, parametric studies were conducted through two-dimensional hydraulic tests, which were carried out at the National Fisheries Research and Development Institute (NFRDI) in South Korea. Those parameters are relative crest width (B/L), wave steepness (H/L), relative crest depth (hB/H), and submerged breakwater configuration. The hydraulic experimental results can be used to predict the performance of the proposed submerged breakwater covered with the multi-function blocks.

• Journal of Power System Engineering
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• v.13 no.1
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• pp.65-71
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• 2009

To address the need for new intelligent sensing, this paper introduces nano sensors made of carbon nanotube (CNT) composites and presents their preliminary experiments. Having smart material properties such as piezoresistivity, chemical and bio selectivity, the nano composite can be used as smart electrodes of the nano sensors. The nano composite sensor can detect structural deterioration, chemical contamination and bio signal by means of its impedance measurement (resistance and capacitance). For a structural application, the change of impedance shows specific patterns depending on the structural deterioration and this characteristic is available for an in-situ multi-functional sensor, which can simultaneously detect multi symptoms of the structure. This study is anticipated to develop a new nano sensor detecting multiple symptoms in structural, chemical and bio applications with simple electric circuits.