• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.12-19
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• 2021

Recently, with frequent earthquakes around the world, research on seismic design and seismic reinforcement of reinforced concrete facilities has been actively conducted from earthquakes. In particular, columns, which are compressed members of reinforced concrete structures, are vulnerable to lateral forces caused by earthquakes, so an appropriate seismic reinforcement method is required. Therefore, this study intended to develop Velcro seismic reinforcement method that is quick and easy to construct. For the development of Velcro seismic reinforcement, the adhesion and tensile strength of the existing industrial velcro was improved. A direct tensile test was also conducted to compare the tensile performance of the newly-developed velcro seismic reinforcement to industrial one. In addition, numerical analysis was performed to predict the seismic performance of RC columns reinforced by industrial and newly-developed velcro. Based on the analysis results, the strength and ductility of the non-seismic and velcro-reinforced RC column were reviewed. The analysis confirmed that both the strength and ductility of non-seismic RC columns reinforced by industrial and newly-developed velcro increased, but the seismic performance of the newly-developed Velcro reinforcement is better than that of industrial velcro.

• Journal of the Korean GEO-environmental Society
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• v.11 no.3
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• pp.23-32
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• 2010

In this study, Generally sandbag was used to reinforce slope or restore levee by using the in-situ material. To increase shear strength of sandbag, the Velcro system was effective for geosynthetic interface and make up for the weakness of shear strength between sandbag to sandbag. In this study, shear properties of geosynthetic-geosynthetic and geosynthetic-soil were evaluated from large scale direct shear tests. The cohesion and the angle of internal friction of each interface was evaluated. And laboratory model tests were performed to compare strength of reinforcement with strength of none reinforcement. As a result of this study, the cohesion and the angle of internal friction of each interface was increased, especially the cohesion was increased more than the angle of internal friction. Also according to the result of model test, the bearing capacity was increased by 20%.

• KOGO NEWS
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• v.4 no.2
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• pp.6-6
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• 2004

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.347-355
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• 2021

During the earthquake, for multi-story structure, if the first floor is soft, the deformation will concentrate on that floor causing a serious damage to the column members which might leads to the collapse of the whole structure like Piloti structure during the Pohang earthquake in Korea. According to the 2016 National Disaster Management Research Institute's "Investigation of Seismic Reinforcement and Cost Analysis of Domestic Non-seismic Buildings", the rate of seismic resistance of private reinforced concrete buildings was 38.3 %. Among them, it was reported that the seismic-resistance ratio of the two to five-story structures was less than 50 %. Accordingly, the government is trying to improve the seismic rate through support projects, but the conventional seismic reinforcement methods are still expensive, and emergency construction is difficult. Therefore, in this study, the field applicability was evaluated by improving the reinforcement method using Velcro, which was developed through the research project of the Ministry of Land, Transport and Maritime Affairs in 2014. In order to improve the performance of the Velcro reinforcement method, introducing the initial tension of Velcro using high foaming rigid urethane filling between the Velcro and concrete of the columns was applied. Additionally, an experiment was conducted to evaluate the ductility of Velcro specimen from the concrete confinement effect. As a result, the ductility of the Velcro specimen was improved compare to Normal specimen. However, the energy dissipation capacity of VELCRO2 is better than VELCRO1, yet the maximum ductility of those two specimens did not show a significant difference. Therefore, the improvement of the internal filler material is still needed to have a better maximum ductility.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.225-232
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• 2008

The object of this paper is to study the flexural strengthening effectiveness on the construction method of bonding of the FRP. The existing FRP flexural strengthening methods were divided into FRP sheet strengthening and FRP plate strengthening according to the FRP condition. For improving the existing construction method, this paper proposed the velcro type anchorage system for temporary bonding material, and flexural strengthening effects were tested. Test variables were bonding methods of the FRP strengthening materials, and total 4 specimens were tested. Following to the test results, it is shown that FRP-plate strengthening method using the velcro can get better workability than existing construction methods, and have excellent strengthening performance including flexural strength, stiffness, ductility and failure aspect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.275-283
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• 2016

In this study, three knee-orthoses (dial lock type, medium size, right side) were used for a quality level test (static bending test and solidity test of the locking system) of the knee-orthosis locking system. In the static bending test, a smaller maximum load was observed in samples A and C compared to the reference standard value (KS P 8408 standard value: 1000 N, sample A: 865 N, sample C: 833 N). In addition, in the solidity test of the locking system, a smaller maximum load was observed in the all samples compared to the referenced standard value (KS P 8411 standard value: 200 N, sample A: 41 N, sample B: 97 N, sample C: 54 N). Korean industrial standards for knee-orthoses and systematic test methods are lacking. Therefore, a systematic management plan for knee-orthoses is required. The result of the current study showed that a systematic management plan for the knee-orthosis locking system is required. In particular, the development of a quantitative and objective test method is needed. The findings of the current study may be useful for monitoring the quality of the knee-orthosis locking system and may provide foundational information for the development of a quantitative and objective test method.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.585-590
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• 2021

Wrist braces are being used for patients with wrist trauma. Recently, many studies have been conducted to manufacture custom wrist braces using 3D printing technology. Such 3D printing customized orthosis has the advantage of reflecting various factors such as reflecting different shapes for each individual and securing breathability. In this paper, the stress on the orthosis by the number and position of Velcro bands that should be considered when manufacturing a 3D printing custom wrist brace was analyzed. For customized orthosis, 3D modeling of the bone and skin regions was performed using an automatic design software (Reconeasy 3D, Seeann Solution) based on CT images. Based on the 3D skin area, a wrist orthosis design was applied to suit each treatment purpose. And, for the elasticity of the brace, a wrist brace was manufactured with an FDM-type 3D printer using TPU material. To evaluate the effectiveness according to the number and position of the Velcro band of the custom 3D printed wrist brace, the stress distribution of the brace was analyzed by the finite element method (FEM). Through the finite element analysis of the wrist orthosis performed in this study, the stress distribution of the orthosis was confirmed, and the number and position of the orthosis production and Velcro bands could be confirmed. These experimental results will help provide quality treatment to patients.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.121-124
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• 2006

This study focuses on the flexural behavior of RC beam with externally bonding FRP reinforcement. FRP-plate strengthening system is mainly installed with an anchor-bolt. But the installation with it has several disadvantage as a complicated work, a high labor costs. To complement these disadvantage, the test is performed about improved FRP-plate strengthening system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.3
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• pp.33-42
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• 2006

From middle of 90's, SCM had emphasized the importance of connection of all companies which participate to a market, and outsourcing has emphasizes the slim structure of companies for pursing cost reduction and service improvement. But outsourcing as '2-1=1' and integration as '1+1=2' not adapt to the advanced market but return to the former state. Besides, it is impossible of subcontractors and logistics companies to execute these strategies which are win-win strategy and outsourcing. So many logistics companies have sharp competition in price recently. Therefore logistics companies have increased the need for a profitable business model and strategy. This paper researches the limitations of logistics market and redefines the role of logistics through the evolution of logistics. Also this paper proposes new role(Logister) and structure(Velcro structure) for not maker-oriented logistics but market-oriented logistics. The introductory case study will help to understand 2 terms(logister and velcro structure).

• Journal of radiological science and technology
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• v.43 no.4
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• pp.243-249
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• 2020

Examination with medical radiography is the most significant advances in medicine in the 21st century. Diagnostic imaging occupies an important position in all medical subjects, surgical and internal medicine, including radiology, orthopedics, and neurosurgery. However, the invention associated with conventional radiography devices has focused only on emphasizing the efficient aspects of the examination or obtaining clearer images without considering the age and disease-induced constraints of the patient's posture. The newly developed X-ray aids to solve this problem can effectively perform X-ray imaging of children's who have difficulty communicating and controlling. It is also thought to be a good way to provide accurate imaging information and minimize radiation exposure for children.