• Journal of the Korean GEO-environmental Society
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• v.5 no.3
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• pp.51-60
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• 2004

In Korea there are recently many attempts to expand a temporary soil nailing system into a permanent soil nailing system since the first construction in 1993. In the soil nailing system, the rigid facing walls act on restraining the deformation of the ground. These are purposed to minimize the damage of adjacent buildings or underground structures. In Korea, to minimize the relaxation of the ground, the soil nailing system in the downtown area is often used experientially together with braced cuts, sheet pile walls, soil cement walls (SCW), or jet grouting walls. However, for the conservative design, the confining effects by the stiff facing have been ignored because the proper design approach of considering the facing stiffness has not been proposed. In this study, various laboratory model tests are carried out to examining the influence the rigidity of facings on the global safety of soil nailing system. Also, the parametric studies using the numerical technique as shear-strength reduction technique are carried out. In the parametric study, the thickness of concrete facing walls is changed to identify the effects of the facing wall stiffness.

• Journal of Fashion Business
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• v.20 no.3
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• pp.119-132
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• 2016

Weighting of silk fabrics have long been practiced in silk fabric trading based on the primary consideration of price-weight, and secondary one of quality improvement in handle, luster, and drape properties. Recent trend of practicing weighting of silk fabrics is, however, focused on the improvement of the handle, luster, drape, and other properties. During the finishing processes of synthetic fiber, nylon, comprising amide structure, include the use of tannic acid, especially in the dyeing. A multitude of studies are being implemented in terms of improving fastness to washing, fastness to light of dyed nylon product, or the light fastness of nylon 6 itself. In this study, the effects of various tannic acid treatments on the physical properties related to the handle of nylon 6 and silk fabrics are examined and reviewed. The effects of treatment condition of the tannic acid, e.g., the concentration of the aqueous tannic acid solution, treatment time, and temperature were investigated. As the concentration of the aqueous solution of tannic acid increased, the bending rigidity values of the silk and nylon 6 fabrics increased. The treated fabrics felt stiff to the touch. Within the mild conditions of bending employed in the bending measurement of KES, nylon 6 treated fabric specimen exhibited a trend of improvement of bending resiliency within the range of small bending deformation. The weight of treated fabrics have all increased. The air-permeability values decreased as the treatment concentration increased. However, the decrease tendency of air permeability values may be alleviated by adjusting the fabric count during the tentering or expanding processes, either by tension adjustment or heat treatment. Optimum conditions of the treatment for nylon 6 are 1.25% tannic acid concentration, bath temperature of $85^{\circ}C$, pH 3.1, and those for silk fabric treatment are 1.25% tannic acid concentration, bath temperature of $85^{\circ}C$, pH 3.1. The treatment conditions will lead to the improvement in the properties of fabrics for summer.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1143-1179
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• 2016

Offshore wind turbines are considered as a fundamental part to develop substantial, alternative energy sources. In this highly flexible structures, monopiles are usually used as support foundations. Since the monopiles are large diameter (3.5 to 7 m) deep foundations, they result in extremely stiff short monopiles where the slenderness (length to diameter) may range between 5 and 10. Consequently, their elastic deformation patterns under lateral loading differ from those of small diameter monopiles usually employed for supporting structures in offshore oil and gas industry. For this reason, design recommendations (API and DNV) are not appropriate for designing foundations for offshore wind turbine structures as they have been established on the basis of full-scale load tests on long, slender and flexible piles. Furthermore, as these facilities are very sensitive to rotations and dynamic changes in the soil-pile system, the accurate prediction of monopile head displacement and rotation constitutes a design criterion of paramount importance. In this paper, the Fourier Series Aided Finite Element Method (FSAFEM) is employed for the determination of static impedance functions of monopiles for OWT subjected to horizontal force and/or to an overturning moment, where a non-homogeneous soil profile has been considered. On the basis of an extensive parametric study, and in order to address the problem of head stiffness of short monopiles, approximate analytical formulae are obtained for lateral stiffness $K_L$, rotational stiffness $K_R$ and cross coupling stiffness $K_{LR}$ for both rough and smooth interfaces. Theses expressions which depend only on the values of the monopile slenderness $L/D_p$ rather than the relative soil/monopile rigidity $E_p/E_s$ usually found in the offshore platforms designing codes (DNV code for example) have been incorporated in the expressions of the OWT natural frequency of four wind farm sites. Excellent agreement has been found between the computed and the measured natural frequencies.

• Steel and Composite Structures
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• v.36 no.2
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• pp.163-177
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• 2020

Concentrically Braced Frames (CBFs) are commonly used in the construction of steel structures because of their ease of implementation, rigidity, low lateral displacement, and cost-effectiveness. However, the principal disadvantage of this kind of braced frame is the inability to provide deformation capacity (ductility) and buckling of bracing elements before yielding. This paper aims to present a novel Composite Buckling Restrained Fuse (CBRF) to be utilized as a bracing segment in concentrically braced frames that allows higher ductility and removes premature buckling. The proposed CBRF with relatively small dimensions is an enhancement on the Reduced Length Buckling Restrained Braces (RL-BRBs), consists of steel core and additional tensile elements embedded in a concrete encasement. Employing tensile elements in this composite fuse with a new configuration enhances the energy dissipation efficiency and removes the tensile strength limitations that exist in bracing elements that contain RL-BRBs. Here, the optimal length of the CBRF is computed by considering the anticipated strain demand and the low-cyclic fatigue life of the core under standard loading protocol. An experimental program is conducted to explore the seismic behavior of the suggested CBRF compare with an RL-BRB specimen under gradually increased cyclic loading. Moreover, Hysteretic responses of the specimens are evaluated to calculate the design parameters such as energy dissipation potential, strength adjustment factors, and equivalent viscous damping. The findings show that the suggested fuse possess a ductile behavior with high energy absorption and sufficient resistance and a reasonably stable hysteresis response under compression and tension.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.295-299
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• 2006

The inner-structure bonded(ISB) sheet metal is defined as a composite sheet metal which has middle layer of truss-structure between two skin sheets. The characteristics such as ultra-light weight, high rigidity, high strength, etc are required especially for automobile parts. The characteristic of ISB sheet metal depends on inner-structure pattern or method of bonding. Pyramid type of crimped expanded metal is used for inner-structure and both of resistance welding and adhesive bonding are applied to make a specimen. As a result of compression test, it is appeared that forming limit is 10% reduction in thickness under a load of 8kgf per unit element(one inner-structure). In case of uniaxial tensile test the non-uniform surface integrity rather than the buckling of inner-structure happened at a load of 450kgf, which indicates elongation of 7.2% and thickness reduction of 13%. The eye-inspection method was applied to examine the defects occurring on the specimen during stretch forming. In case of biaxial stretch forming only the non-uniform deformation on the surface of a skin sheet could be observed. The forming limit in stretching of ISB sheet metal with the hemi-spherical punch of 150mm in diameter was 3mm in forming depth and 5% reduction in thickness.

• Steel and Composite Structures
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• v.22 no.1
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• pp.113-139
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• 2016

The nonlinear seismic responses of steel buildings with perimeter moment resisting frames (PMRF) and interior gravity frames (IGF) are estimated, modeling the interior connections first as perfectly pinned (PPC), and then as partially restrained (PRC). Two 3D steel building models, twenty strong motions and three levels of the PRC rigidity, which are represented by the Richard Model and the Beam Line Theory, are considered. The RUAUMOKO Computer Program is used for the required time history nonlinear dynamic analysis. The responses can be significantly reduced when interior connections are considered as PRC, confirming what observed in experimental investigations. The reduction significantly varies with the strong motion, story, model, structural deformation, response parameter, and location of the structural element. The reduction is larger for global than for local response parameters; average reductions larger than 30% are observed for shears and displacements while they are about 20% for bending moments. The reduction is much larger for medium- than for low-rise buildings indicating a considerable influence of the structural complexity. It can be concluded that, the effect of the dissipated energy at PRC should not be neglected. Even for connections with relative small stiffness, which are usually idealized as PPC, the reduction can be significant. Thus, PRC can be used at IGF of steel buildings with PMRF to get more economical construction, to reduce the seismic response and to make steel building more seismic load tolerant. Much more research is needed to consider other aspects of the problem to reach more general conclusions.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.306-310
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• 2007

Restrictive dermopathy is a rare autosomal recessive disorder in which rigidity or tautness of the skin from the second trimester causes a fetal akinesia deformation sequence (FADS) and early death. Characteristic features include taut skin with prominent subcutaneous vessels, widely open fontanelles and cranial sutures, distinctive facies, flexion contractures, pulmonary hypoplasia, sparse eyelashes and and eyebrows, thin dysplastic clavicles. The histologic abnormalities of the skin are located in a thin dermis, consisting of compactly arranged collagen fibers, scanty elastic fiber. The dermoepidermal junction is flat, and epidermal appendages are absent, miniaturized or immature. The presence of adipose tissue may be increased. We report on the first Korean case of restrictive dermopathy with typical clinical features and histological findings.

• Journal of Fashion Business
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• v.7 no.4
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• pp.121-128
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• 2003

A new textile material, poly(trimethylene terephthalate) polymer, has been introduced to the textile industry. The structure of PTT is similar to the PET, while the tensile deformation and subsequent recovery property is better than that of PET. In this study, the physical and mechanical properties of textile woven fabrics made of PTT, PET, and nylon 6 yarns as the filling yarn were determined using the Kawabata Evaluation System (KES), including tensile, bending, shearing, compression, and surface related parameters. On top of these measurements, the subjective ratings by evaluators were performed on the fabric samples. From the examination of the stress-strain behavior of the yarn specimens focused on the recovery mode, it was evident that the PTT specimen developed lower stress at 3% elongation. The subsequent recovery curve showed that the PTT has less stress-decay rate than the other specimens, implying that the recovery behavior of the PTT is recommendable for the end-uses including stretchable textile materials, sports wears, etc. The KES bending rigidity(B) value of the PTT sample fabric was lower than that of the PET sample fabric. Subjective evaluation of the fabric samples by the evaluators on the descriptive word pair "soft - not soft" showed similar tendency with the KES B determination of the fabric samples.

• Journal of Fashion Business
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• v.20 no.2
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• pp.124-133
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• 2016

Currently the fashion industry is developing to create a novel culture due to the very sensitive and knowledge-oriented advancement of the IT industry. With fast turnover of information, consumers have come to have a more diverse desire for purchasing. Cubical expression techniques, which empathizes formativeness, can be a creative expression method adjusting into the trend of this era. Along with functional aspects of consumers, even in a textile manufacturing sector, new materials are required to meet sensitive and emotional aspects. Consumers' desire for new and creative designs and the development and adoption of new materials are essential to meet their emotions. The IT industry and fashion industry are forced to combine and a 3D apparel CAD system has been developed, enabling virtual clothing to be represented within a computer virtual space. All processes such as design, pattern creation, sewing and simulation are possible in 3D level. Digital clothing can shorten the production process time and is very effective in that it can reduce clothing waste generated during the sample production. This paper reviewed the works of Dutch designer, Iris van Herpen, who has developed formative designs. She tries to build, construct, and sculpt employing diversified materials other than soft textile materials, as shown in her series of fashion shows. The materials include films, 3D printed polymers, stiff and sheer organza, and artificial leather textiles. A few characteristics of her works have been selected in order to prepare patterns exhibiting the traits. The paper further focused on the physical features of the textile materials used to express similar techniques and its various forms were reviewed.

• Journal of the Korean Geosynthetics Society
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• v.10 no.1
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• pp.1-8
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• 2011

The problems like a deterioration of loading bearing capacity, an exaggeration of settlement and lateral deformation are able to be generated, meanwhile structures are built in soft ground. Top-Base method is belonged to a rigidity mat foundation method which is used to surface treatment of soft ground. This method makes an effect to increase the bearing capacity of foundation using friction force, and prevent the differential settlement. Further more, the In-Situ Top-Base method has advantages in the phase of economic effect by reduction of the construction cost and offers an expediency on construction comparing with precast products. This paper presents the way of the estimation of bearing capacity for In-Situ Top-Base method through field plate load test in soft ground. It utilizes the results to a future design by analyzing the properties in the existing study and designs through these analysis and calculating the top-base method's reasonable range.