• Earthquakes and Structures
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• v.1 no.3
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• pp.307-326
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• 2010

This paper is concerned with the optimal seismic design of added viscous dampers in yielding plane frames. The total added damping is minimized for allowable values of local performance indices under the excitation of an ensemble of ground motions in both regular and irregular structures. The local performance indices are taken as the maximal inter-story drift of each story and/or the normalized hysteretic energy dissipated at each of the plastic hinges. Gradients of the constraints with respect to the design variables (damping coefficients) are derived, via optimal control theory, to enable an efficient first order optimization scheme to be used for the solution of the problem. An example of a ten story three bay frame is presented. This example reveals the following 'fully stressed characteristics' of the optimal solution: damping is assigned only to stories for which the local performance index has reached the allowable value. This may enable the application of efficient and practical analysis/redesign type methods for the optimal design of viscous dampers in yielding plane frames.

• Journal of Life Science
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• v.14 no.1
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• pp.57-60
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• 2004

To get basic information on the Korea local corn lines collected from Busan and Gyungnam Province, a total of 49 lines were classified by the principal component analysis method. The lines were classified into 4 lineal groups by the taxonomic distance. Croup I included 11 lines, and groupII, groupIII and groupIV included 20 lines, 14 lines and 4 lines, respectively. Four groups could be characterized as follows: Croup I : early maturity, short plant, small ears, small kernels, low tillering and medium yielding. Croup II : early maturity, tall plant, large ears, large kernels, multi-ears, low tillering and high yielding. GroupIII: late maturity, short plant, small ears, small kernels, high tillering and low yielding. Croup W medium maturity, tall plant, large ears, small kernels, prolific ears, high tillering and higher yielding.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.180-189
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• 1999

This paper describes the collapse characteristics of the rectangular tube under eccentric compressive load. Local buckling stress and maximum crippling load are investigated. A thin-walled tube under load is controlled by local buckling or yielding of material according to the ratio of thickness to width (t/b) of the cross section, and subsequent collapse of the section. The relationship can be divided into three regions : elastic , post-buckling and crippling . the load-displacement relationship is theoretically presented in each region by introducing the stress distribution of the cross section in the loading process. And the maximum load carrying capacity is derived in the closed form as a function of normal stress on the flange and web.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.57-61
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• 2003

A new silkworm variety, Chugangjam, with a sex-limited larval marking and high silk yielding for summer-autumn rearing season is $F_1$ hybrid between Jam 147, a Japanese race bred from P8503/8453, and Jam 148, a Chinese race from M8306/Jam 130. Jam 147, Japanese parent of the Chugangjam showed a high GCA (general combining ability) in pupation percentage and Jam 148, Chinese parent, showed a high GCA in pupation percentage and single cocoon weight. In the local adaptability test performed at 8 local areas in autumn of 2001, Chugangjam was 5% higher in cocoon yield and 8% in raw silk productivity in the 10,000 of the 3rd molted larvae, respectively, than the check variety Daesungjam.

• Journal of Ocean Engineering and Technology
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• v.16 no.5
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• pp.66-72
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• 2002

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. However, effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. In this study, we investigated failure modes of locally wall thinned pipes and AE signals by bending test. From test results, we could be divided four types of failure modes of ovalization, crack initiation after ovalization, local buckling and crack initiation after local buckling. And fracture behaviors such as elastic region, yielding region, plastic deformation region and crack progress region could be evaluated by AE counts, accumulative counts and time-frequency analysis during bending test. The result of the frequency range is expected to be basic data that can inspect plants in real-time.

• Journal of Korean Society of Steel Construction
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• v.25 no.2
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• pp.131-139
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• 2013

The object of this paper is to perform the experiments to investigate the relationship of the resistance forces and the failure temperatures on the failure behaviors of H-shaped steel compressive members. H-shaped members(SS400) were used for the test models and the tests for the elevated temperatures were performed by ISO 834 in FILK(Fire Insurers Laboratories of Korea). The local, overall buckling stresses and a yielding stresses for the failure temperatures were compared with the compressive stresses for the loading forces of test models, the yielding strength and elastic modulus reduction factor of the steel at a high temperature were based on the criteria of the EC3(Eurocode 3) Part1.2(1993). The slenderness ratio was fixed by 45.4 and the compressive forces corresponded with 50%, 70% and 80% of the yielding forces at the normal temperatures were chosen for the loading forces of the test models. The failure temperatures of the test models were investigated under three kinds of loading conditions. It was known that the resistance forces have come close to the yielding forces, not the elastic buckling loads evaluated by EC3 at the failure temperatures obtained from the tests which are related to the failure temperatures and the loading stresses.

• Steel and Composite Structures
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• v.41 no.6
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• pp.861-871
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• 2021

This study aims at investigating the hysteretic performance of a novel composite wall panel fabricated by infilling aerated concrete blocks into a novel light-steel frame used for low-rise residential buildings. The novel light-steel frame is consisted of two thin-wall rectangular hollow section columns and a truss-beam assembled using patented U-shape connectors. Two bare light-steel frames and two composite wall panels have been tested to failure under horizontal cyclic loading. Hysteretic curves, lateral resistance and stiffness of four specimens have been investigated and analyzed. Based on the testing results, it is found that the masonry infill can significantly increase the lateral resistance and stiffness of the novel light-steel frame, about 2.3~3 and 21.2~31.5 times, respectively. Failure mode of the light-steel frame is local yielding of the column. For the composite wall panel, firstly, masonry infill is crushed, subsequently, local yielding may occur at the column if loading continues. Hysteretic curve of the composite wall panel obtained is not plump, implying a poor energy dissipation capacity. However, the light-steel frame of the composite wall panel can dissipate more energy after the masonry infill is crushed. Therefore, the composite wall panel has a much higher energy dissipation capacity compared to the bare light-steel frame.

• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.275-284
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• 2004

The behavior of the connection for beam-to-column weak axis connection and its details should be identified. Thus, each element is considered a panel zone, and the horizontal stiffener's presence or absence and position in bracket-type welding connection are used as variables to compare the behavior of strong axis connection and weak axis connection. In this study, the strength of connection is calculated by substituting the simple beam-strengthened vertical stiffeners for connection in the presence of horizontal stiffeners. In the absence of horizontal stiffeners, the strength of connection can be calculated using local flange bending strength considering local web yielding strength, web crippling, and web buckling strength. The results of the theoretical analysis and experiments are compared.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.319-326
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• 2001

In this paper, 3-D frame design using refined plastic-hinge analysis accounting for local buckling is developed. This analysis accounts for material and geometric nonlinearities of the structural system and its component members. Moreover, the problem associated with conventional refined plastic-hinge analyses, which do not consider the degradation of the flexural strength caused by local buckling, is overcome. Efficient ways of assessing steel frame behavior including gradual yielding associated with residual stresses and flexure, second-order effect, and geometric imperfections are presented. In this study, a model consisting of the width-thickness ratio is used to account for local buckling. The proposed analysis is verified by the comparison of the LRFD results.

• Journal of Ginseng Research
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• v.22 no.1
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• pp.11-17
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• 1998

To develop a new ginseng varieties with good quality and high yielding, a lot of individual ginseng plants were selected in the farmer's fields in 1972. Among them, a promising line, 7259-3-1, has been developed through comparative cultivation of several lines selected with pure line separation of local races in Korea Ginseng '||'&'||' Tobacco Research Institute. Preliminary and advanced yield trials were performed for 8 years. It was then designated as "KG 101" and tested in the regional yield and adaptation trials for 10 years (1981-1990). KG101 has a green stem with light violet and orange-yellow fruit and flowers 3-7 days later than local race, Takyungjong. Taproot of KG101 was longer than local race Jakyungjong, and root yield of KG101 was 9% higher than local race Jakyungjong. In red ginseng quality, the rates of Chun-Jeesam (Chun and Jee means 1st and 2nd grade, respectively) were 22.3% and 9.4% for KG101 and Jakyungjong, respectively. In these results, it was clarified that KG101 was superior ginseng line with good quality.y.