• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.22-29
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• 2008

This paper describes the developed results of vision system for the recognition of material management characters, which was included in the billet image. The material management characters, which was marked at the surface of billet, should be recognized before billet moves to the next process. Our vision system for the character recognition includes that CCD camera system which acquire billet image, optical transmission system which transmit captured image to the long distance, input and output system for the interface with existing system and software for the character recognition. We have installed our vision system at the wire rod line of steel & iron plant and tested. Also, we have performed inspection of durability, reliability and recognition rate. Through the testing, we have confirmed that our system have high recognition rate, 98.6%.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.4
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• pp.367-372
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• 2002

Experimental study was conducted for lapping process after WEDMed specimen. In order to decide the lapping depth of the specimen, the number of the grain size was increased from 400, 600 to 800 to obtain the better surface. Observation of scanning electron microscope, hardness test, surface roughness test and energy dispersive spectrum(EDS) analysis were used for this experimental study. From the comparison and analyses of the results of between the wire-cut electrical discharge machining and the lapping, the following results were obtained. The surface roughness after lapping was found to be improved as increasing the number of lapping process like 1st, 2nd, 3rd lapping and the number of grain size such as 400, 600, 800. The surface hardness after increasing the lapping depth of the specimen was slowly increased. It was found that after 3rd lapping process the hardness was reached the hardness of original base material. It was found that the small amount of coating components within 3% was remained after the 1st lapping process, compared to that approximately 16% after WEDM process.

• Steel and Composite Structures
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• v.32 no.5
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• pp.559-569
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• 2019

The bond strength between composite laminates and concrete is a key factor that controls the behavior of concrete members strengthened with fiber reinforced polymer (FRP) sheets, which can be affected by several parameters such as thermal stresses and surface preparation. This article presents the result of an experimental study on the bond strength between FRP sheets and concrete at ambient temperature after specimens had been exposed to elevated temperatures of up to $200^{\circ}C$. For this purpose, 30 specimens of plain concrete with dimensions of $150{\times}150{\times}350mm$ were prepared. Three different conventional surface preparation methods (sandblasting, wire brushing and hole drilling) were considered and compared with a new efficient method (fiber implantation). Deformation field during each experiment was monitored using particle image velocimetry. The results showed that, the specimens which were prepared by conventional surface preparation methods, preserved their bond integrity when exposed to temperature below glass transition temperature of epoxy resin (about $60^{\circ}C$). Beyond this temperature, the bond strength and stiffness decreased significantly (about 50%) in comparison with control specimens. However, the specimens prepared by the proposed method displayed higher bond strengths of up to 32% and 90% at $25^{\circ}C$ and $200^{\circ}C$, respectively.

• Journal of Powder Materials
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• v.26 no.3
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• pp.214-219
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• 2019

In this study, the microstructure and characterization of an overlay welding layer using Fe-based composite powders are reported. The effects of the number of passes and composition of powders on the microstructure and mechanical properties are investigated in detail. The welding wire and powders are deposited twice on a stainless-steel rod using a laser overlay welding process. The microstructure and structural characterization are performed by scanning electron microscopy and X-ray diffraction. The mechanical properties of the first and second overlay layers are analyzed through the micro-Vickers-hardness tester and abrasion wear tester. In the second overlay layer, the hardness and specific wear are approximately 840 Hv and $2.0{\times}10^{-5}mm^3/Nm$, respectively. It is suggested that the increase of the volume fractions of $(Cr,Fe)_7C_3$ and NbC phases in the second welding layer enhances the hardness and wear resistance.

• Korean Journal of Materials Research
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• v.29 no.11
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• pp.709-714
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• 2019

In order to observe the microstructure and morphology of porous titanium -oxide thin film, deposition is performed under a higher Ar gas pressure than is used in the general titanium thin film production method. Black titanium thin film is deposited on stainless steel wire and Cu thin plate at a pressure of about 12 Pa, but lustrous thin film is deposited at lower pressure. The black titanium thin film has a larger apparent thickness than that of the glossy thin film. As a result of scanning electron microscope observation, it is seen that the black thin film has an extremely porous structure and consists of a separated column with periodic step differences on the sides. In this configuration, due to the shadowing effect, the nuclei formed on the substrate periodically grow to form a step. The surface area of the black thin film on the Cu thin plate changes with the bias potential. It has been found that the bias of the small negative is effective in increasing the surface area of the black titanium thin film. These results suggest that porous titanium-oxide thin film can be fabricated by applying the appropriate oxidation process to black titanium thin film composed of separated columns.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.18-24
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• 2021

Polymers, polymer compounds, are very moldable at low temperatures and have good strength against weight, and hence, are often used in the interior and exterior materials of cars. Owing to the increasing environmental problems, emission regulations have become stricter, which has increased the use of lightweight polymers as substitutes for metal materials. Therefore, as the use of polymer increases, extensive research is being conducted on the bonding technology of polymers, such as polyurethane and epoxy. However, the increased cost and environmental pollution by adhesives caused by the polymer manufacturing plant depend on the chemical composition or the manufacturer's mix ratio. To compensate for this issue, a laser beam is irradiated through a highly permeable polymer (PC) placed on top of an absorbent polymer (ABS) to transfer the laser output to the ABS polymer and fuse them at the interface. Moreover, enabling laser penetrating bonding by placing a stainless steel wire mesh between the two polymers can achieve improved bonding strength compared to conventional heterogeneous polymer bonding.

• Journal of Veterinary Clinics
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• v.39 no.2
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• pp.65-69
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• 2022

A 5 day-old Warmblood foal was presented with a quarter crack due to the dam accidentally stepping on his left hind foot. Physical examination revealed the vertical crack included the coronary band of the medial side of the left hind hoof (quarter crack) with the lower pastern avulsion wound. Different from adult horses, the foot of the 5 day-old foal lacked adequate hoof wall thickness for stainless steel wire insertion and hoof size for a reinforcing fabric to be applied. Therefore, the authors decided to stabilize the edges of the cracked wall only by the polymethyl methacrylate (PMMA) composites without wiring and a reinforcing fabric application; and gluing a plastic shoe that was reshaped to protect the lower pastern and to spread pressure to other parts of the hoof when bearing weight. Disinfection and a supportive bandage were applied daily for 2 weeks. A month after the hoof crack accident, lameness had diminished. The quarter crack in this foal was treated successfully by the application of the composites three times with a reshaped gluing shoe, with approximately a month interval over the 4 months. After 4 months, it presented a successful functional recovery and needed no further treatment. When followed up 8 months after the accident, it revealed successful outcomes without hoof shape distortion and unbalanced hoof/limb growth.

• Composites Research
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• v.35 no.6
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• pp.439-446
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• 2022

In this study, fiber-reinforced composite coil springs for automobiles were manufactured using the braiding method, and mechanical tests and damage evaluation were performed to confirm their safety. Through the analysis of the load-displacement behavior, the stiffness of the springs was evaluated to meet the specifications. In addition, the distribution of voids and the impregnation rate on the spring wire section were analyzed to clearly understand the criteria for the mechanical properties of the composite material. Moreover, the tested springs were visually inspected to confirm the damaged parts, and the failure mode was analyzed by observing crack initiation and propagation behavior of cross-sectional samples taken from the crack and failure adjacent areas of springs using SEM.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.144-145
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• 2021

This study analyzed the cases of cracks in piles due to the use of followers under construction conditions where water exists inside the piles, and confirmed whether the piles were cracked through a field test simulating the construction conditions in which water pressure inside the piles was generated by a hammer. According to the construction case, under the construction condition where the pile length is 20% to 30% shorter than the drilled length, about 80% cracks occur, so there is a high possibility of cracking due to water inside the pile. A field test was conducted to confirm the type of pile failure due to hammer under the construction condition in which water exists inside the pile. The pile head was not destroyed by the compressive load, and one or more longitudinal cracks occurred along the PC steel wire. The closed end pile generates water pressure by hammer. the follower and cushion(compression plywood) must be drilled at least 0.4D. It is expected that improved quality control will be possible as the water pressure inside the pile is reduced.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.1
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• pp.94-107
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• 2024

This study developed compression pants with excellent wearability and signal quality by approaching the design of wireless sEMG monitoring pants from the perspective of technical design, including the evaluation of wearability and the stable wireless transmission of signals through electrode and circuit design, and using e-textiles. An electrode, sewn with silver thread and a circuit stitched in a zigzag pattern using stainless steel wire, were applied. Additionally, polyurethane sealing tape was used to enhance adherence to the skin and reduce electrical resistance. Conductive snaps completed the design, allowing attachment and detachment to the bio-signal acquisition mainboard. Through the subjects' evaluation, it was determined that the final pants were applied with a pattern reduction rate of 25% to provide superior comfort according to different body parts while also minimizing skin irritation around the thigh circuit. The final pants for wireless sEMG monitoring, which demonstrated stable transmission of wireless measurements, was positively evaluated in terms of cognitive acceptability. This study is significant in that it achieved an optimal design by considering both technical aspects and the electrical characteristics of bio-signal monitoring garments, as well as the wearer's perception when designing smart wear.