• Earthquakes and Structures
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• 제10권3호
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• pp.629-643
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• 2016

Among all the natural disasters, earthquakes are the most destructive calamities since they cause a plenty of injuries and economic losses leaving behind a series of signs of panic. The present study highlights the moment-curvature relationships for the structural elements such as beam and column elements and Non-Linear Static Pushover Analysis of RC frame structures since it is a very simplified procedure of non-linear static analysis. The highly popular model namely Mander's model and Kent and Park model are considered and then, seismic risk evaluation of RC building has been conducted using SAP 2000 version 17 treating uncertainty in strength as a parameter. From the obtained capacity and demand curves, the performance level of the structure has been defined. The seismic fragility curves were developed for the variations in the material strength and damage state threshold are calculated. Also the comparison of experimental and analytical results has been conducted.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2001년도 Australian-Korean Rheology Conference 2001
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• pp.160.2-160
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• 2001

• Advances in nano research
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• 제16권2호
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• pp.165-173
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• 2024

The production of multipurpose cotton fabrics aimed at elevating the quality of aerobic and dance sportswear is explored in this study. Powder metallurgy, known for its high efficiency in manufacturing technological components with minimal waste, is employed as a method for fabricating brush ferrules for painting. The utilization of iron-copper material, prepared through powder metallurgy, enhances the strength and quality of the brush ferrules. A microscopic analysis reveals a robust interconnection between the particles of each layer achieved through isostatic pressure, resulting in a favorable microstructure. The relative density and strength of parts produced from copper-iron powder exhibit an increase with higher pressure levels. The application of this material in brush ferrules ensures their durability and longevity, thereby supporting the creation of artwork. The evolution of art over time reflects changing ideas and possibilities, and technological advancements have significantly improved artistic tools. The role of tools in artistic expression is paramount, and the integration of powder metallurgy materials in brush ferrules fortifies their artistic importance. In summary, this study underscores the advantages of powder metallurgy in augmenting the quality of art tools and facilitating artistic creation.

• Advances in concrete construction
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• 제14권5호
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• pp.355-368
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• 2022

This paper investigates the impact of length and volume fractions (VFs) of banana fibres (BFs) on the mechanical and physical properties of concrete. The mechanical properties were compressive strength, splitting tensile, flexural strength, and bond stress, while the physical properties were unit weight and absorption. The slump test was used to determine workability. The concrete's behaviour with BFs was studied using scanning electron microscopy. Experimental work of concrete mixtures with BFs of various lengths (12 mm, 25 mm, and 35 mm) and VFs (0%, 0.5%, 1.0%, and 1.5%) were carried out. The samples did not indicate any agglomeration of fibres or heterogeneity during mixing. The addition of BFs to concrete with VFs of up to 1.50% for all fibre lengths have a significant impact on mechanical properties, also the longer fibres performed better than shorter ones at all volume fractions of BFs. The mix10, which contain BFs with VFs 1.5% and length 35 mm, demonstrated the highest mechanical properties. The compressive strength, splitting tensile, flexural strength, and bond stress of the mix10 were 37.71 MPa, 4.27 Mpa, 6.12 MPa, and 6.75 MPa, an increase of 7.37%, 20.96%, 24.13%, and 11.2% over the reference concrete, which was 35.12 MPa, 3.53 MPa, 4.93 MPa, and 6.07 MP, respectively. The absorption is increased for all lengths by increasing the VFs up to 1.5%. Longer fibres have lower absorption, while shorter fibres have higher absorption. The mix8 had the highest absorption of 4.52%, compared to 3.12% for the control mix. Furthermore, the microstructure of concrete was improved through improved bonding between the fibres and the matrix, which resulted in improved mechanical properties of the composite.

• Structural Engineering and Mechanics
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• 제32권2호
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• pp.301-320
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• 2009

Damage assessment for buried structures against an internal blast is conducted by considering the soil-structure interaction. The structural element under analysis is assumed to be rigid-plastic and simply-supported at both ends. Shear failure, bending failure and combined failure modes are included based on five possible transverse velocity profiles. The maximum deflections with respect to shear and bending failure are derived respectively by employing proper failure criteria of the structural element. Pressure-Impulse diagrams to assess damage of the buried structures are subsequently developed. Comparisons have been done to evaluate the influences of the soil-structure interaction and the shear-to-bending strength ratio of the structural element. A case study for a buried reinforced concrete structure has been conducted to show the applicability of the proposed damage assessment method.

• 한국의류산업학회지
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• 제16권1호
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• pp.160-166
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• 2014

Patent and utility indicate international competitiveness in the knowledge-based society of the $21^{st}$century where both the quantity and quality of the nation's scientific intelligence and innovative technology represent key criteria to evaluate its strength. Thus, discerning the trends of patents is inevitable for further development. This research is centered on apprehending the technological current of the functional clothing of Korea, through an analysis of patents and utility models. The number of patent applications in Korea was low until the mid-1990s. However, it began to grow rapidly in the 2000s and the number of patents surpassed the number of utility starting in 2006. The technological level of invention in this field has been turned into a higher level. The IPC code with the strongest application was the field related to temperature controllable clothing (A41D 13/005), followed by surgeon or patient apparel related fields (A41D 13/12), and reflective or luminous safety devices (A41D 13/01).The main technological idea was to give functionality that could protect the human body from various hazards and represents the goal of various applied techniques. About 66% of domestic patent applications belong to individuals; however, the proportion of corporate or institutional applications(including universities) remains poor. Consequently, more systematic and long-term support for research on patents is required.

• International Journal of Concrete Structures and Materials
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• 제11권1호
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• pp.45-58
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• 2017

Recent investigations have pointed out that current code provisions specifying that the stiffness of reinforced concrete elements is strength independent, and therefore can be estimated prior to any strength assignment, is incorrect. A strength allocation strategy, suitable for preliminary structural design of medium height wall-frame dual systems, is presented for allocating strength in such buildings and estimating the dependable rigidities. The design process may be implemented by either the approximate continuous approach or the stiffness matrix method. It is based on the concept of the inelastic equivalent single-degree-of-freedom system which, the last few years, has been used to implement the performance based seismic design. The aforesaid strategy may also be used to determine structural configurations of minimum rotation distortion. It is shown that when the location of the modal centre of rigidity, as described in author's recent papers, is within a close distance from the mass axis the torsional response is mitigated. The methodology is illustrated in ten story building configurations, whose torsional response is examined under the ground motion of Kobe 1995, component KJM000.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.457-460
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• 2006

Recently ultra high strength concrete is actively being developed and studied, and this trend is explained with the following effects. Technological effects expected from the application of ultra high strength concrete include the reduction of section, the decrease of structure mass and the improvement of workability. Belite cement has properities like low heat of hydration, excellent long term strength, and durablity without admixture. so, Belite cement is suitable for mass structure which is needed high strenghth, high fluidity and heat property. The objective of this study is to examine the suitability of mixture ratio through experiment of basic physical properties and provide materials for the field application of ultra high strength concrete.

• Structural Engineering and Mechanics
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• 제26권3호
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• pp.231-250
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• 2007

The influence of masonry infills with eccentric openings on the seismic performance of reinforced concrete (r/c) frames that were designed in accordance with current code provisions are investigated. Eight 1/3-scale, single-story, single-bay frame specimens were tested under cyclic horizontal loading up to a drift level of 4%. In all examined cases the shear strength of columns was higher than the cracking shear strength of solid infill. The parameters investigated include the shape and the location of the opening. Assessment of the behavior of the frames is also attempted, based on the observed failure modes, strength, stiffness, ductility, energy dissipation capacity and degradation from cycling loading. Based on these results there can be deduced that masonry infills with eccentrically located openings has been proven to be beneficial to the seismic capacity of the bare r/c frames in terms of strength, stiffness, ductility and energy dissipation. The location of the opening must be as near to the edge of the infill as possible in order to provide an improvement in the performance of the infilled frame.

• Structural Engineering and Mechanics
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• 제83권2호
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• pp.245-257
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• 2022

As the main lateral load resisting system in high-rise reinforced concrete structures, the mechanical performance of shear wall has a significant impact on the structure, especially for high-rise buildings. Steel corrosion has been recognized as an important factor affecting the mechanical performance and durability of the reinforced concrete structures. To investigate the effect on the seismic behaviour of corroded reinforced concrete shear wall induced by corrosion, analytical investigations and simulations were done to observe the effect of corrosion on the ultimate seismic capacity and drift capacity of shear walls. To ensure the accuracy of the simulation software, several validations were made using both non-corroded and corroded reinforced concrete shear walls based on some test results in previous literature. Thereafter, a parametric study, including 200 FE models, was done to study the influence of some critical parameters on corroded structural shear walls with boundary element. These parameters include corrosion levels, axial force ratio, aspect ratio, and concrete compressive strength. The results obtained would then be used to propose equations to predict the seismic resistance and drift capacity of shear walls with various corrosion levels.