• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.130-137
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• 2003

The pipe of CFRP for bicycle frame is designed and made for light weight of bicycle and then its suitability to bicycle frame is verified by comparing the other material i.e. steel, Cr-Mo steel, Al alloy pipe for bicycle frame. The pipe of CFRP is laminated to [0/$\pm$45]$_T$ and made by tape winding method and then its degree of light weight is evaluated by comparing the other pipes which is made by steel etc.

• Journal of the Korea Furniture Society
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• v.29 no.1
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• pp.40-48
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• 2018

This study analyzes the contribution of hanok that construction in reducing greenhouse gas (GHG) emissions in Korea by calculating the carbon storage of hanoks and comparing it to different housing types in Korea. The hanok is a traditional Korean house. And it were first designed and built in the $14^{th}$ century during thd Joseon Dynasty. According to our results, the number of hanoks in 2016 was approximately 547,085 which was accounting for 7.8% of the total construction market, This study found Gyeongbuk with 95,083, Jeonnam with 88,981, Gyeongnam with 76,388 and Seoul with 43,519 hanoks. According to the GHG Inventory Report for 2016, Korea's total annual GHG emissions amounted to 650 million $tCO_2$, with the carbon stocks in hanoks amounting to 19.2 million $tCO_2$. This accounts for 2.8% of Korea's total GHG emissions and 46.1% of the carbon absorbed by forests. Our results show that hanoks store four times more carbon than light-frame-wood-houses, and 15 times more carbon than concrete-reinforced and steel-frame houses. The main factors causing the hanok industry slowdown are the high construction costs, lack of government support, and insufficient knowledge of hanok architecture. Therefore, to further increase the carbon stock of hanok, more research is needed to improve the technical use of wood and reduce construction of the hanok and prepare legal and institutional arrangements related to hanok industry.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.36.1-37
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• 2021

Six images of IRC+10216 taken by the Hubble Space Telescope at three epochs in 2001, 2011, and 2016 are compared in the rest frame of the central carbon star. An accurate astrometry has been achieved with the help of Gaia Data Release 2. The positions of the carbon star in the individual epochs are determined using its known proper motion, defining the rest frame of the star. In 2016, a local brightness peak with compact and red nature is detected at the stellar position. A comparison of the color maps between 2016 and 2011 epochs reveals that the reddest spot moved along with the star, suggesting a possibility of its being the dusty material surrounding the carbon star. Relatively red, ambient region is distributed in an Ω shape and well corresponds to the dusty disk previously suggested based on near-infrared polarization observations. In a larger scale, differential proper motion of multiple ring-like pattern in the rest frame of the star is used to derive the average expansion velocity of transverse wind components, resulting in ~12.5 km s-1 (d/123 pc), where d is the distance to IRC+10216. Three dimensional geometry is implied from its comparison with the line-of-sight wind velocity determined from half-widths of submillimeter emission line profiles of abundant molecules. Uneven temporal variations in brightness for different searchlight beams and anisotropic distribution of extended halo are revisited in the context of the stellar light illumination through a porous envelope with postulated longer-term variations for a period of 10 years.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.1
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• pp.63-69
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• 2008

A fatigue test on the steel welded L-shaped frame was conducted. The frame was consisted with carbon steel tube and reinforced bracket. The four type reinforced brackets were fabricated. They were two rectangular plate reinforced bracket, two sided pentagon plate reinforced bracket, triangular plate reinforced bracket and fully reinforced bracket. The fatigue test of frame was conducted with axial tension loading. The fatigue simulation of the steel welded L-shaped frame was also performed by the finite element method with code FEMFAT. The frame of fully reinforced bracket had the highest fatigue life and reinforced quality factor.

• Structural Engineering and Mechanics
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• v.73 no.4
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• pp.381-395
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• 2020

Study on the inelastic response of bare and masonry infilled Reinforced Concrete (RC) frames repaired using Carbon Fibre Reinforced Polymers (CFRP) and Glass Fiber Reinforced Polymers (GFRP) subjected to quasi- static loading is presented in the work. The hysteresis behaviour, stiffness retention, energy dissipation and damage index are the parameters employed to analyze the efficacy of FRP strengthening of bare and brick in-filled RC frames. It is observed that there is a significant improvement in load carrying capacity of brick infilled frame over bare RC frame. Also FRP strengthened brick infilled frame performs much better than FRP repaired bare frame under quasi static loading. Repair and retrofitting of brick infilled RC frame shows an improved load carrying and damage tolerance capacity than control frame.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.250-263
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• 2001

The up and down speed of heddle frames that produce woven cloth by insertion of weft yarns between warp yarns has been increased recently much for productivity improvement, which induces higher inertial stresses and vibrations in the heddle frame. the heddle frame is required to reduce its mass because the heddle frame contributes the major portion of the stresses in the heddle frames during accelerating and decelerating. Conventional aluminum heddle frames have fatigue life of around 5 months at 550rpm due to their low fatigue flexural strength as well as low bending stiffness. In this work, since carbon/epoxy composite materials have high specific fatigue strength(S/p), high specific modulus(E/p), high damping capacity and sandwich construction results in lower deflections and higher buckling resistance, the sandwich structure composed of carbon/epoxy composite skins and polyurethane foam were employed for the high-speed heddle frame. The design map for the sandwich beams was accomplished to determine the optimum thickness and the stacking sequences for the heddle frames. Also the effects of the number of ribs on the stress of the heddle frame were investigated by FEM analyses. Finally, the high-speed heddle frames were manufactured with sandwich structures and the static and dynamic properties of the aluminum and the composite heddle frames were tested and compared with each other.

• Composites Research
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• v.19 no.6
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• pp.1-7
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• 2006

This is the preliminary study to develop composite window frame of commercial aircraft using VaRTM process. For two candidate carbon fabrics(triaxial overbraid, sleeving braider), specimens were fabricated using VaRTM process, and the physical & mechanical property tests were performed to obtain the material properties according to ASTM. FEM analysis for each candidate carbon fabric was performed to find the minimum number of plies and weight for composite window frame to satisfy the design requirements. In this study, Tsai-Wu strength failure criterion was used to evaluate the safety of structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.69-74
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• 2000

In this dissertation, experimental research was carried out to study the hysteretic behavior of reinforced concrete frame designed by high performance techniques, using carbon fiber plate, diagonal bracing system with or without steel frame. Experimental programs were carried to evaluate the structural performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Specimens(RFCP, RFXB, RFXB-F), designed by the improvement of earthquake-resistant performance, were attained more load-carrying load-carrying capacity stable hysteretic behavior.

• Journal of Korean Neurosurgical Society
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• v.37 no.6
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• pp.422-426
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• 2005

Objective: Different types of interbody fusion cages are available for use in the surgical treatment of degenerative cervical diseases. The purpose of this study is to assess the technical feasibility, clinical efficacy and radiological results of intervertebral fusion with a carbon composite Osta-Pek frame cage (Co-Ligne AG, Switzerland) following anterior cervical discectomy. Methods: 41 patients (25males and 16females) with minimum 6months follow-up were included in the study. Disc height, cervical lordotic angle, segmental angle, and fusion rate were assessed by lateral radiographs. In this retrospective analysis, clinical outcome was assessed as evaluated according to Odom's criteria. Results: Fifty-four cages were implanted in 30 single-level, 9 two-level, and 2 three-level procedures. The mean disc height, cervical lordosis angle, segmental angle were $4.2{\pm}1.8mm,\;23.5{\pm}7.2^{\circ},\;2.3{\pm}3.3^{\circ}$ pre-operatively and $5.3{\pm}2.1mm,\;24.2{\pm}8.3^{\circ},\;3.8{\pm}3.5^{\circ}$ at 6months after the surgery. Six months after surgery, there was radiographic evidence of fusion in 92.7% (38/41) of the patients. According to Odom's criteria, 37 of 41 (90.2%) patients experienced good to excellent functional recovery. Conclusion: These clinical and radiological results suggest that the carbon composite Osta-Pek frame cages are safe and effective alternative to autologous bone graft after anterior cervical discectomy for treatment of degenerative cervical disease.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.93-98
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• 2016

Cold plasma and heat treatment were selected as technologies to reduce unburned carbon in fly ash to less than 1.0%. Both cold plasma and heat treatment made it possible to eliminate unburned carbon to less than 1.0%. In the case of fly ash, which almost entirely eliminated unburned carbon with an ignition loss of 0.5%, heat treatment caused adhesion among particles and the BET specific surface area rapidly decreased as the mean particle size increased. On the other hand, with cold plasma, unburned carbon elimination caused the BET specific surface area to decrease and, as no adhesion occurred among particles, the mean particle size became small. Also, cold plasma treatment allowed small spherical particles confined within the unburned carbon particles to be released with the elimination of the unburned carbon frame, so that the quantity of fine particles had a tendency to slightly increase.