• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.92-93
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• 2020

The test method to be developed is to determine whether the waterproof layer applied to the leak-prone part such as cracks and joints has defects such as tearing or lifting of the waterproof layer due to the influence generated from the behavior of the structure under complex deterioration conditions. This is to evaluate the performance of the waterproofing method afterwards. Therefore, by notifying only the pass or fail, the unique mechanical properties of the material or method used are notified to the test client to limit the physical properties of the test body, thereby determining and supplementing the weaknesses of the user material in advance to improve the high quality. We want to prevent damage from water leakage through production and distribution of materials.

• Transactions of Materials Processing
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• v.32 no.4
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• pp.199-207
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• 2023

The stainless steel basket-bowl, a critical component of washing machines, is characterized by its unique two-tiered circular shape. This study explores the potential of a draw-bead free die design to address tearing concerns in the prospective plastic layer during the drawing operation. In order to prevent wrinkles that may arise from the absence of a draw-bead, a two-stage punch configuration is proposed. The influence of the blank holder force on wrinkle reduction is also examined. Finite element analysis is employed to evaluate the proposed die design by analyzing the wrinkle shape and strain mode. The results confirm that the stainless steel basket-bowl can be successfully drawn without wrinkles utilizing the proposed two-stage punch without a draw-bead on the blank holder. These findings contribute to the development of more efficient and reliable manufacturing processes for the stainless steel basket-bowl production.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.4
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• pp.565-582
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• 2022

In recent years, Jumchi-Hanji made of mulberry paper is used as a material for fashion items. This study examined the effect of the type of Choji method (Oebal-teugi or Ssangbal-teugi), layer number (one or two layers) and Jumchichigi time (20, 40, or 60 minutes) on the tensile, wet tensile, tearing and bursting strengths of Jumchi-Hanji. Jumchi-Hanjis used as test samples in this study were made from mulbery paper which was manufactured with either bleached or unbleached paper mulberry from Thailand. The results showed that Jumchi-Hanji made with two layers of mulberry papers had higher strength properties than Jumchi-Hanji made with only one layer. The strength properties of Jumchi-Hanji also increased with longer Jumchichigi time. Furthermore, this study confirmed that the effects of Jumchichigi time on Jumchi-Hanji strengths differed based on the type of Choji method, the layer number of mulberry papers used, and the specific strength property measured. Therefore, to guarantee the strength properties required by the application of Jumchi-Hanji paper as a fashion material, it is necessary to carefully consider the adequate Choji method and layer number to apply in the manufacture of Thai mulberry paper and the adequate duration time needed to perform Jumchichigi to Thai mulbery paper.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.191-192
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• 2022

It was intended to evaluate whether the primer affects the physical performance of the waterproofing membrane coating. For this end, the physical performance change of the urethane waterproofing membrane coating was evaluated for urethane-based and polymer-based primers. As a result of the evaluation, it was confirmed that the type of primer may affect the physical performance of the waterproofing membrane coating. In particular, a difference in performance of more than 100% was confirmed in tensile strength and percentage elongation. Through these results, it was confirmed that the selection of the primer was important. In the future, follow-up studies on various waterproofing membrane coatings are needed.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3677-3691
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• 2023

Since containment building is the major shielding structure to ensure safety of nuclear power plant, the structural behavior and ultimate pressure capacity of containments must be studied in depth. This paper addresses ambiguous issue of determining free-field position for liner failure by suggesting an expanded free-field region and comparing internal pressure capacities obtained by test data, conservative assumption and suggested free-field region. For this purpose, a practical approach to determine the free-field position for the evaluation of liner tearing is carried out. The maximum principal strain histories versus internal pressure capacities among different free-field positions at various azimuths and elevations are compared with those at the equipment hatch as a conservative assumption. The comparison shows that there are considerable differences in the internal pressure capacity at liner failure within the expanded free-field region compared to the vicinity of the equipment hatch. Additionally, this study proposes an approximate correlation with conservative factors by considering the expanded free-field ranges and material characteristics to determine realistic failure criteria for liner. The applicability of the proposed correlation is demonstrated by comparing the internal pressure capacities of full-scale containment buildings following liner failure criteria according to RG 1.216 and an approximate correlation.

• Journal of Fashion Business
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• v.27 no.5
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• pp.108-120
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• 2023

Recently, interest in eco-friendliness and sustainability has been increasing due to the rapid progress of fast fashion and the crisis of sudden environmental changes after COVID-19. This study aims to develop upcycling textiles and express product design using digital 3D to realize a sustainable fashion industry and present environmental aspects, diversity, creativity, and new directions in fashion industry design. The research method is to develop and pattern upcycling textile designs by applying weaving techniques with waste materials. It uses the developed upcycling textile design in digital 3D to incorporate it into clothing fashion and shows the utility and practicality of upcycling textile design. As a result of the study, the appearance is realistic when outputting DTP of upcycling textile design. It endures without loosening or tearing, making it a durable and creatively expressive fashion item. Texpro 3D mapping reduces the time and cost of making actual sample fabric. Upcycling textile design and 3D CLO virtual clothing are combined to produce actual clothing samples, resulting in zero waste reduction due to cutting and sewing. This study anticipates actively and continuously advancing the development of upcycling textile design and digital 3D in terms of ethics and the environment.

• Structural Engineering and Mechanics
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• v.88 no.1
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• pp.95-107
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• 2023

In this study, circular thin-walled reinforced high strength concrete-filled steel tube (RHSCFST) stub columns with various tube thicknesses (i.e., 1.8, 2.5 and 3.0mm) and reinforcement ratios (i.e., 0, 1.6%, 2.4% and 3.2%) were fabricated to explore the influence of these factors on the axial compressive behavior of RHSCFST. The obtained test results show that the failure mode of RHSCFST transforms from outward buckling and tearing failure to drum failure with the increasing tube thickness. With the tube thickness and reinforcement ratio increased, the ultimate load-carrying capacity, compressive stiffness and ductility of columns increased, while the lateral strain in the stirrup decreased. Comparisons were also made between test results and the existing codes such as AIJ (2008), BS5400 (2005), ACI (2019) and EC4 (2010). It has been found that the existing codes provide conservative predictions for the ultimate load-carrying capacity of RHSCFST. Therefore, an accurate model for the prediction of the ultimate load-carrying capacity of circular thin-walled RHSCFST considering the steel reinforcement is developed, based on the obtained experimental results. It has been found that the model proposed in this study provides more accurate predictions of the ultimate load-carrying capacity than that from existing design codes.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4647-4658
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• 2023

In this paper, elastic-plastic fracture mechanics analysis is performed to determine the critical crack sizes of the multipurpose canister (MPC) manufactured using austenitic stainless steel under dynamic loading conditions that simulate drop accidents. Firstly, dynamic finite element (FE) analysis is performed using Abaqus v.2018 with the KORAD (Korea Radioactive Waste Agency)-21 model under two drop accident conditions. Through the FE analysis, critical locations and through-thickness stress distributions in the MPC are identified, where the maximum plastic strain occurs during impact loadings. Then, the evaluation using the failure assessment diagram (FAD) is performed by postulating an external surface crack at the critical location to determine the critical crack depth. It is found that, for the drop cases considered in this paper, the principal failure mechanism for the circumferential surface crack is found to be the plastic collapse due to dominant high bending axial stress in the thickness. For axial cracks, the plastic collapse is also the dominant failure mechanism due to high membrane hoop stress, followed by the ductile tearing analysis. When incorporating the strain rate effect on yield strength and fracture toughness, the critical crack depth increases from 10 to 20%.

• Korean Journal of Bronchoesophagology
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• v.10 no.2
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• pp.17-21
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• 2004

Background Insertion of tracheal stent in the treatment of benign tracheal & bronchial disease has increased since the introduction of expandable metallic stent. Material & Methods : Between Jan, 1995 and Feb. 2004, eight patients who had benign tracheo-bronchial disease underwent insertion of expandable metallic tracheal stent. We retrospectively analyzed stent insertion indications, complications, and following the result. Results : Surgical indications were post-intubation tracheal stenosis (1 case), tracheal stenosis following tracheal surgery (2 cases), tracheo-esophageal fistula (2 cases), broncho-pleural fistula(1 case), left main bronchus stenosis following bronchoplasty (1 case), and left main bronchus stenosis due to mediastinal repositioning (1 case). Expandable metallic tracheal stent was inserted in five patients to resolve dyspnea caused by airway obstruction, and to prevent recurrent pneumonia in three patients. The complication developed in 6 patients $75\%$; 3 cases of distal stenosis due to growth of granulation tissue, and one case each of tearing of posterior membrane, aggravation of tracheo-esophageal fistula, and airway partial obstruction due to stent migration. The stent was removed in 5 patients and tracheal surgery (tracheal resection and end to end anastomosis with primary repair of esophagus, pericardial patch tracheo-bronchoplasty, tracheal repair and omental wrapping) was performed in 3 patients. Conclusion Insertion of self expandable metallic stent in benign tracheo-bronchial disease is an effective means of relieving dyspnea for only a short period, and it did not increase the long term survival. Better means of treatment of benign tracheo-bronchial stenosis in necessary.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.469-476
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• 2012

In this paper, a finite element domain decomposition method using local and mixed Lagrange multipliers for a large scal structural analysis is presented. The proposed algorithms use local and mixed Lagrange multipliers to improve computational efficiency. In the original FETI method, classical Lagrange multiplier technique was used. In the dual-primal FETI method, the interface nodes are used at the corner nodes of each sub-domain. On the other hand, the proposed FETI-local analysis adopts localized Lagrange multipliers and the proposed FETI-mixed analysis uses both global and local Lagrange multipliers. The numerical analysis results by the proposed algorithms are compared with those obtained by dual-primal FETI method.