• Structural Engineering and Mechanics
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• v.48 no.6
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• pp.791-807
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• 2013

Ultra High Performance Cementitious Composites with compressive strength 200MPa (UHPCC-200) is proposed for the structural design of super high hybrid wind turbine tower to gain durability, ductility and high strength design objectives. The minimal wall thickness is analyzed using basic bending and compression theory and is modified by a toque influence coefficient. Two cases of wall thickness combination of middle and bottom segment including varied ratio and constant ratio are considered within typical wall thickness dimension. Using nonlinear finite element analysis, the effects of wall thickness combinations with varied and constant ratio and prestress on the structural stress and lateral displacement are calculated and analyzed. The design limitation of the segmental wall thickness combinations is recommended.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.25-33
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• 1991

The slope stability analysis of Carsington dam is performed, considering the effects of pore water pressure, slip surface configuration, lateral stress and various shear strengths. Without yellow clay layer, the Bowles' and STABR programs were used to find the circular slip surface which has the maximum safety factor. At last using the Morgenstern-Price method, the effects of rainfall and strength of yellow clay were mainly considered in the back analyses after failure. It was found that (1) the potential slip was not predicted in the analysis based on the modified Bishop method without considering the yellow clay layer, and (2) the crllapse of dam had been occurred according to the critical shear strength of the yellow clay and pore water pressure increase.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.113-120
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• 1994

Large Concrete Panel Structures behave quite differently from frame or monolithic shear wall structures because of the weakness of Joint in stiffness and strength. The joint experiences large deformation such as shear-slip in vertical and horizontal joint and rocking and crushing in horizontal joint because of localized stress concentration, but the wall panels behave elastically under cyclic loads. In order to describe the nonlinear behavior of the joint in the analysis of PC structures, different analysis technique from that of RC structures is needed. In this paper, for analysis of large concrete panel subassemblage subjected to cyclic loads, the wall panels are idealized by elastic finite elements, and the joints by nonlinear spring elements with various load-deflection relationship. The analytical results are compared with the experimental results on the strength, stiffness, energy dissipation and lateral drift, and the effectiveness of this computer analysis modelling technique is checked.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.614-617
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• 2008

This paper presents the numerical investigation of the characteristics of biaxial flexure specimens for the Biaxial Flexure Test(BFT) which was recently developed to measure the biaxial tensile strength of concrete. Using FEM, the effect of size and eccentricity on the specimens was evaluated. The parameters such as radious of the support and the loadings, thickness and free length were studied. The results of the FE analysis were entirely consistent with the predictive solution, when b/agt;0.4, h/alt;0.6 and the thickness of the specimens were increased. On the other hands, when b/agt;0.4, those with lesser free length showed good results. To limit the difference between the stresses at the end points of 2b as the specimen was sustained and the stress at the center point of the specimen are not over 10%, lateral eccentricity was analyzed to be in the limits of 3%.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.1-11
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• 2017

Evolutionary studies conducted on NAC (NAM, ATAF1&2, and CUC2) genes for all major groups of land plants, indicate the presence of the NAC subfamilies, even in the early land plants. The varied roles played by NAC proteins in plant growth and development range from the formation of shoot apical meristem, floral organ development, reproduction, lateral shoot development, and defense responses to biotic and abiotic stresses. Considering the value and importance of solanaceous crops, the study of NAC proteins in these plants needs to be intensified. This will help to identify and functionally characterize their promoters, which will subsequently aid in engineering plants with improved performance under stressful conditions. In this review, the functionally characterized NAC transcription factors specific to tomato, potato, tobacco, chili pepper and eggplant (aubergine) are summarized, clearly indicating their biological functions in the defense mechanism of the plants, against biotic and abiotic stresses.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.589-596
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• 1998

Experimental studies are investigated for RC column retrofitting under cyclic load. Design considerations are jacketing of steel plate of carbon fiber with epoxy bonding, use of unbonded plate, additional concrete grouting, ratio of additional longitudinal steel reinforcement and longitudinal configuration of additional ties. Investigated results are 1) jacketing and additional reinforcements are effective for strengthening, 2) use of additional grouting is less effective with respect to increased section. Future studies are needed to evaluate the requirements about additional reinforcements for member stress level, 3) bond between original and additional grout concrete.

• Speech Sciences
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• v.11 no.1
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• pp.73-83
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• 2004

Electromyographic studies of the cricopharyngeus muscle using hooked wire electrodes were performed in thyroidectomized patients. The shape of the cricoid cartilage and soft tissue thickness in the postcricoid area were evaluated during pitch elevation and pitch lowering using conventional neck lateral films. The cricopharyngeus muscle simultaneously activated in the initial task of speech and continuously activated. Its activity lessened in the interrogative stress contrast of sentence terminals and increased in the pitch lowered contrast of sentence terminal. On the radiologic findings the cricoid cartilage was tilted backward during high pitched phonation and tilted forward during low pitched phonation. The soft tissue thickness of postcricoid area was thicker at the low pitch than at high pitch. At low pitch the cricoid cartilage paralleled along the vertebral column. This result suggests that the bulging of cricopharyngeus muscle in contraction induce a thickened the postcricoid area thickened, and exert pressure anteriorly exerted on the cricoid cartilage. This contraction of the cricopharyngeus muscle may result in shortening the vocal fold and lowering pitch.

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.133-142
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• 2006

An experimental study was conducted to investigate the effectiveness of transverse steel in reinforced concrete tied columns subjected to monotonically increasing axial compression. Eighteen large-scale columns($260{\times}260{\times}1,200mm$) were tested. Effects of such main variables as concrete compressive strength, configurations of transverse steel, transverse reinforcement ratio, spacing of transverse steel, and spalling of concrete cover were investigated. High-strength concrete columns under concentric axial loads show extremely brittle behavior unless the columns are confined with transverse steel that can provide sufficiently high lateral confinement pressure. A consistent decrease in the deformability of the column test specimens was observed with increasing concrete strength. Test results of this study were compared with existing confinement models of modified Kent-Park, Sheikh-Uzumeri, Mander, and Saatcioglu-Razvi. The comparison indicates many existing models to predict the behavior of confined concrete overestimate or underestimate the ductility of confined concrete.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.02a
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• pp.78-83
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• 1999

The ultimate settlement of soft clay consists of three parts: $\circled1$ immediate settlement, S$\sub$d/; $\circled2$ Primary consolidation settlement, S$\sub$c/; $\circled3$ Secondary consolidation settlement, S$\sub$s/. In general, S$\sub$c/ can be accurately calculated by one-dimensional consolidation and S$\sub$s/ or S$\sub$d/ may be ignored. This paper focuses on a calculation method to estimate the immediate settlement induced by lateral deformation of subgrade, to which shear stress is applied by embankment on soft ground. Immediate settlement and consolidation settlement are discussed by comparing the field measurement of the Yangsan test embankment on treated soft foundation by vertical paper drains.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.5
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• pp.537-544
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• 2009

In order to increase the critical speed of rotating disks of which functional material could not be changed such as in optical and magnetic data storage disks, a new disk with a rim reinforced by composite material is proposed and its concept is verified by numerical analysis. Stress distributions are found for the rotating disk composed of two annular disks of which materials are isotropic inside and orthotropic outside. Dynamic equation is formulated in order to calculate the natural frequency and critical speed. For the solution of lateral vibration, a rotational symmertry condition is applied along circumferential direction and a finite element interpolation with Hermite polynomial is performed along the radial direction to obtain a proper solution. According to the results, reinforcing a disk at rim makes critical speeds drastically increased, and induces a buckling phenomenon in mode (0,0) which occurs over the lowest critical speed.