• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.4
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• pp.726-736
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• 2018

This study determined how the upper body shape of elderly women changes with age in order to improve the fit of clothing worn by elderly women. Thirty-nine healthy elderly Japanese women had their body measurements taken by measuring tape and a 3D body line scanner (Hamamatsu Model #C9036-02) from December 2011 to March 2012 at a university in Tokyo. It was found that the shoulder line shortens in women between the ages of 70 and 74, but that the upper arm lengthens in women between the ages of 75 and 79. It was also found that the upper part of the scapular area rolls forward in women between the ages of 70 and 74, and that the point of the back which protrudes the most-the lower scapular area-rolls forward in women between the ages of 75 and 79. The results will be helpful for designing clothes for elderly women as their body shape changes with age.

• Advances in nano research
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• v.15 no.1
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• pp.49-57
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• 2023

As composite materials are used in many applications, the modern world looks forward to significant progress. An overview of the application of composite fiber materials in sports equipment is provided in this article, focusing primarily on the advantages of these materials when applied to sports equipment, as well as an Analysis of the influence of sports equipment of fiber-reinforced composite material on social sports development. The present study investigated surface morphology and physical and mechanical properties of S-glass fiber epoxy composites containing Al₂O₃ nanofillers (for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%). A mechanical stirrer and ultrasonication combined the Al₂O₃ nanofiller with the matrix in varying amounts. A compression molding method was used to produce sheet composites. A first physical observation is well done, which confirms that nanoparticles are deposited on the fiber, and adhesive bonds are formed. Al₂O₃ nanofiller crystalline structure was investigated by X-ray diffraction, and its surface morphology was examined by scanning electron microscope (SEM). In the experimental test, nanofiller content was added at a rate of 1, 2, and 3% by weight, which caused a gradual decrease in void fraction by 2.851, 2.533, and 1.724%, respectively, an increase from 2.7%. The atomic bonding mechanism shows molecular bonding between nanoparticles and fibers. At temperatures between 60 ℃ and 380 ℃, Thermogravimetric Analysis (TGA) analysis shows that NPs deposition improves the thermal properties of the fibers and causes negligible weight reduction (percentage). Thermal stability of the composites was therefore presented up to 380 ℃. The Fourier Transform Infrared Spectrometer (FTIR) spectrum confirms that nanoparticles have been deposited successfully on the fiber.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.402-403
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• 2003

Garment manufacture represents the final stage of processing a finished fabric. The main task of the garment manufacturer is to produce shell structures out of flat fabrics to match the shape of the human body, and the most acceptable means of joining textile materials for apparel use is by sewing. On the sewing process, the bottom layer is pushed forward by the feed-dog, but the presser foot tends to retard the passage of the top layer. Since the friction between the layers is low, is possible that the components will move out of phase and pucker. (omitted)

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.187-199
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• 2009

We present real.time, rapid detection of Mycoplasma pneumonia in phosphate buffered saline (PBS) inside a Y.channel polydimethylsiloxane (PDMS) microfluidic device by means of optical fiber monitoring of latex immunoagglutination. The latex immunoagglutination assay was performed with serially diluted Mycoplasma pneumonia solutions using highly carboxylated polystyrene particles of 390nm and 500nm diameter conjugated with monoclonal anti. Mycoplasma pneumonia . Proximity optical fibers were located around the viewing cell of the device, which were used to measure the increase in 45${\b{o}}$ forward light scattering of the immunoagglutinated particles. The detection limit was less than 50 $pgml^{-1}$ both for 390nm and 500nm microspheres with the detection time less than 90 seconds.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.85-92
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• 2007

This paper presents a design optimization of a new Advanced Active Blade Twist (AATR-II) blade incorporating single crystal Macro Fiber Composites (MFC) and conducts vibratory loads reduction analysis using an obtained optimal blade configuration. Due to the high actuation performance of the single crystal MFC, the AATR blade may reduce the helicopter vibration more efficiently even with a lower input-voltage as compared with the previous ATR blades. The design optimization provides the optimal cross-sectional configuration to maximize the tip twist actuation when a certain input-voltage is given. In order to maintain the properties of the original ATR blade, various constraints and bounds are considered for the design variables selected. After the design optimization is completed successfully, vibratory load reduction analysis of the optimized AATR-II blade in forward flight condition is conducted. The numerical result shows that the hub vibratory loads are reduced significantly although 20% input-voltage of the original ATR blade is used.

• Korean Journal of Optics and Photonics
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• v.20 no.3
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• pp.189-194
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• 2009

We demonstrate a ring type wavelength swept laser incorporating a fiber Fabry-Perot tunable filter in a laser cavity using 1300 nm semiconductor optical amplifier as a gain medium. The output characteristics of the wavelength swept laser according to the applied scanning frequencies are analyzed in the temporal and spectral domain. The output of the wavelength swept laser decreases dramatically as the scanning frequency increases. And there is a significant peak power imbalance between the forward scan and the backward scan as the scanning frequency increases. Its use in practical applications might be limited.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.7
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• pp.1249-1255
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• 2008

1530nm band has been studied as pump wavelength for long-wavelength-band erbium-doped fiber amplifier (L-band EDFA). The pump source is built using a tunable light source and cascaded conventional-band (C-band) EDFA. The L-band EDFA uses a forward pumping scheme. Within the 1530nm band, 1545nm pump demonstrates 0.45dB/mW gain coefficient, which is twice better than that of conventional 1480nm pumped EDFA. The noise figure of 1530nm pump is at worst 6.36dB, which is 0.75dB higher than that of 1480nm pumped EDFA. Such high gain coefficient indicates that the L-band EDFA consumes low power.

• Steel and Composite Structures
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• v.31 no.5
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• pp.517-527
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• 2019

To move forward in large steps rather than in small increments, the community would benefit from a systematic and comprehensive database of multi-scale composites and measured properties, driven by comprehensive studies with a full range of types of fiber-reinforced polymers. The multi-scale hierarchy is a promising chemical approach that provides superior performance in synergistically integrated microstructured fibers and nanostructured materials in composite applications. Achieving high-efficiency thermal conductivity and mechanical properties with a simple surface treatment on single-walled carbon nanotubes (SWCNTs) is important for multi-scale composites. The main purpose of the project is to introduce ozone-treated SWCNTs between an epoxy matrix and basalt fibers to improve mechanical properties and thermal conductivity by enhancing dispersion and interfacial adhesion. The obvious advantage of this approach is that it is much more effective than the conventional approach at improving the thermal conductivity and mechanical properties of materials under an equivalent load, and shows particularly significant improvement for high loads. Such an effort could accelerate the conversion of multi-scale composites into high performance materials and provide more rational guidance and fundamental understanding towards realizing the theoretical limits of thermal and mechanical properties.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.339-342
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• 2005

In long-period fiber grating (LPFG) to be made up optical fiber sensors, resonance coupling occurs between the forward-propagating core mode and cladding modes at the wavelength that satisfy the Phase matching condition. The resonance wavelength and the coupling strength depends strongly on the external environment like temperature, strain, and ambient index. These characteristics can be utilized for various applications as optical fiber sensors. fabrication of optical fiber gratings is typically based on the photosensitivity effect, i.e. the permanent change of the refractive index upon irradiation of the UV beam, and therefore, fabrication of the optical fiber with high phososensitivity is an important part of the research on optical fiber gratings. In this work, we measured the effort of to-doping of boron on the index difference between the core and cladding of the optical fiber and the sensitivity of the LPFC to the temperature and bending changes. We observed that the index difference between the core and the cladding decreased by $(1.69{\times}10^{-4}/SCCM)$ and the temperature sensitivity of the resonance wavelength shirt decreased by $(0.01145nm/^{\circ}C/SCCM)$. The dependence or the bending-induced changes or the transmission characteristics of LPFG on the tore-cladding index difference was investigated experimentally. The measurement results indicate that the bending sensitivity increases as the index difference decreases.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.227-233
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• 2009

We investigated the polarization-mode dispersion (PMD) tolerance for 40Gb/s non-return to zero (NRZ), duobinary NRZ, return to zero (RZ), carrier-suppressed RZ (CS-RZ), and duobinary-carrier-suppressed RZ (DCS-RZ) modulation formats with a forward error correction (FEC) coding. The power penalty has been calculated as a measure of the system performance due to PMD. After comparison of the PMD tolerance of various modulation formats, our results suggest that RZ signals have the best tolerance against the effect of first-order PMD only. The duobinary NRZ modulation format is most resilient to PMD when both first- and second-order PMD are considered. However, the duobinary NRZ modulation format is the most sensitive to the incident angle of the input signal to a fiber axis in the presence of first- and second-order PMD, leading to incident angle-dependent power penalty. The coding gain by FEC can cope with the power penalties induced by first- and second-order PMD up to a DGD value of 16ps.