• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.89-94
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• 2011

The swivel joint is an important part in hydraulic machine. The analysis on the material was made using the EDAX method to localize the swivel joint. Also, the modeling and design drawing were finalized with application of 3 dimensional measurement and structure analysis. The prototype product based on design drawing was made with cutting and grinding process. No abnormalities were found in the prototype product through the durability test and measurement. The localized swivel joint with light weight, price reduction and diversification was developed in this study.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.941-946
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• 2018

Currently, due to the development of technology, the industry is proceeding with the development of advanced materials with high performance such as light weight, heat resistance and electric conductivity. Carbon Fiber Reinforced Plastics (CFRP) is an excellent material with high heat resistance, high strength and thermal shock resistance. In order to obtain excellent hole shape in CFRP drilling, we compared the modified drill shape and the conventional carbide drill. On the other hand, we determine the proper helix angle by observing the CFRP surface according to the helix angle at the trimming of the end mill proceeding after the hole machining.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.164-165
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• 2019

Light-weight foamed concrete using cement as a raw material consumes a lot of energy and generates $CO_2$ because of the high temperature firing process in the manufacturing process of cement. This study was carried out to evaluate the use of blast furnace slag through the properties analysis by substituting a certain amount of blast furnace slag as an industrial by-product as a substitute for cement. The experimental results showed similar characteristics to those of using only cement when the blast furnace slag fine powder was used in an appropriate amount. Therefore, if a certain amount of cement is replaced with blast furnace slag powder, it can maintain similar quality, reduce natural resources and energy consumption, and reduce carbon dioxide emissions.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1803-1806
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• 2008

Various efforts of reducing the green house gas in the whole industrial fields including railway industry have been implemented. Tilting train is the key example because it can run more faster on the existing rail than others due to its composite body. The system has an advantage of light weight but also a task to solve, recycling of composite material. To recycle the CFRP(Carbon Fiber Reinforced Plastic), there are two typical methods; chemical and thermal method. In this study, more environmentally friendly recycling method was recommended through the environmental function through comparing both recycling methods.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.76-81
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• 2021

A plastic noise barrier is a structure installed to minimize noise, and it is composed of the main plate, sound-absorbing plate, and sound-absorbing material. Plastic noise barrier structures have several advantages compared to other products, such as light weight, anticorrosion, durability, easy assembly, rapid construction, and low costs. In this study, the main and sound-absorbing plates were manufactured through extrusion molding, and the sound-absorbing plate was finished with a press to improve the conventional injection molding. Extrusion molding dies and punch dies were designed, and a profile extrusion-molding system was developed. Thus, inexpensive and efficient sound-absorbing and main plates can be produced, and the noise barrier structure can be assembled rapidly. Additionally, a noise barrier structure with extended service life and excellent quality can be constructed by creating uniform free space to accommodate increased temperatures after assembly and installation.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.760-765
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• 2011

This paper presents a study of the tensile behavior of carbon and glass fiber reinforced epoxy hybrid laminates manufactured by vacuum assisted resin transfer molding (VARTM). The objective of this study was to develop and characterize carbon fiber reinforced plastic hybrid composite material that is low cost and light-weight and that possesses adequate strength and stiffness. The effect of position and content of the glass fabric layer on the tensile properties of the hybrid laminates was examined. The strength and stiffness of the hybrid laminates showed a steady decrease with an increase of the glass fabric content this decrease was almost linear. Fracture strain of these laminates showed a slight increasing trend when glass fabric content was increased up to 3 layers, but at a glass fabric content > 3 layers the strain was almost constant. When glass fabric layers were at both outer surfaces, the hybrid laminate exhibited a slightly higher tensile strength and elastic modulus due to the small amount of glass yarn pull-out.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.53-61
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• 2015

This paper reports the test results of the floating floor system used to reduce the floor noise of apartment buildings. Recently, many soft resilient materials placing between the reinforced concrete slab and finishing mortar are used. The resilient material should not only reduce the floor impact sound vibration from the floor but also support the load on the floor. Thus, even if soft resilient materials satisfy the maximum limitation of light-weight impact sound and heavy-weight impact sound, these materials may not support the load on the floor. The experimental program involved conducting sixteen sound insulation floating floor specimens. Three main parameters were considered in the experimental investigation: resilient materials, loading location, and layers of floor. Experimental results indicated that the stiffness of resilient material significantly influenced on the structural behavior of floating floor system. In addition, the deflection of the floating concrete floor loaded at the side or coner of the specimen was greater than that of the floor loaded at the center of the specimen. However, the aerated concrete did not effect on the cracking strength of floating floor system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1675-1682
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• 2012

Weight reduction is increasingly being considered very important in light of air pollution and the exhaustion of resources. As a result, many automotive components are being replaced by Al and Mg alloys, and studies are increasingly focusing on the same. However, the use of Mg alloys is limited because they have higher material cost and lower productivity owing to the difficult forming conditions compared with Al alloys. In this study, the tube extrusion process conditions of an automotive bumper back beam were analyzed using FEA. Material tests were performed to determine the properties, and experiments and analyses for a simple shape were performed to define the data for heat generation during plastic deformation. Then, the analyses of the product were carried out by considering various temperatures and ram speeds. The conditions were then established, and a product without surface defects was extruded successfully.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.161-167
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• 2023

Recently, floor impact sound has become a serious social problem in Korea. There is an increasing need to improve floor impact sound performance using floor covering installed on the floor of apartment houses. KS F ISO 717-2 and KS F 2863 require measurement under conditions in which the resilient material is not installed. But most apartment houses in Korea install resilient materials to reduce floor imapct sound. The performance evaluation method of floor covering should provide reduced performance for use by residents of apartment houses with resilient materials. Therefore, this paper proposes a reduction performance evaluation under the conditions in which a resilient material is installed to verify the performance of floor covering.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.193-193
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• 2022

Cowpea(Vigna unguiculata L. Walp) has a low fat and protein content and a relatively high starch content, so it is mainly used in various ways for song-pyeon sediment, rice-cake paste, and porridge. In Yeonggwang-gun, Jeollanam-do, cowpea for seed production is being cultivated for the localization of raw material for Rice cake with ramie leave. A cowpea variety 'Jang-Alchan' was improved from the cross between IT145373 and IT145391 at the JARES in 2019. 'Jang-alchan' has an erect plant with an intermediate plant habit, light purple-colored corolla, and heart-shaped leaflets. 'Jang-alchan' has an orange-yellow seed seed-surface of faint luster, and brown and straight pods when matured. The stem length of 'Jang-alchan' was 48cm, 9cm longer than that of the control cultivar 'Okdang' and the 100-seed weight was 14.1g. The weight ratio of the seed coat for the entire seed was 11.2%, which was 0.2%p lower than that of the control cultivar. Field resistance of 'Jang-alchan' to leaf and systemic diseases was similar to that of the control cultivar. Is field resistance of 'Jang-alchan' to lodging was slightly lower than that of the control cultivar. The average yield of 'Jang-alchan' was 1.85ton per hectare, which was 14% higher than that of the control cultivar 'Okdang', 'Jang-Alchan' does not require the installation of an espalier-net and is taller than the existing supplied 'Okdang', so it can be harvested by combine harvesting. In addition, it is expected to contribute to the localization of raw material grains for regional specialties as it can be cultivated over a large area.