• Steel and Composite Structures
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• v.4 no.5
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• pp.403-418
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• 2004

Lateral sway is most likely to control the design of semi-rigid steel frames where the frame arrangements do not include any form of bracing. This paper investigates the sway behaviour of semi-rigid regular steel frames i.e., frames having the same arrangement of beam and column sections at all levels, and hence proposes some design charts for the prediction of sway that eliminate the need for doing any numerical modelling. Schueller's equation has also been modified to incorporate connection flexibility in addition to its original rigid frame considerations. All the proposed methods have been validated using results obtained from numerical analysis.

• Journal of The Korean Digital Architecture Interior Association
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• v.4 no.1
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• pp.36-45
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• 2004

Allowable stress design method have been most widely used in steel structure in Korea. Recently, not only high-rise buildings but also medium or low-rise buildings were designed as steel structure. Most of low-rise steel buildings are designed as ordinary moment resisting frames(MRF). But MRFs don't have any lateral force resisting devices such as bracing in braced frames. This study focuses mainly on nonlinear seismic response analyses of small scale steel frames which will be used later as specimens for the evaluation of MRF's seismic performances. The main parameters of analyses are arrangement of column axis, $P-{\Delta}$ effect, acceleration factor etc. The object of this paper is to estimate the seismic performances of MRFs, which are mostly designed in Korea, through the results of response analyses.

• Journal of the Korean Ceramic Society
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• v.42 no.5 s.276
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• pp.304-307
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• 2005

The possible configurations of hydroxyl group in hexagonal hydroxyapatite were identified through molecular orbital calculation. The molecular orbital interaction between O and H in hydroxyl column was analyzed using charge variation and Bond Overlap Population (BOP). We supposed 5 kinds of O-H bond configurations as cluster types of I, II, III, IV, and V. Mulliken's population analysis was applied to evaluate ionic charges of O, H, P, and Ca ions, and BOPs (Bond Overlap Populations) in order to discuss the bond strength change by the atomic arrangement. The stability of each O-H bond configuration was analyzed using bond overlap and ionic charge.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.357-363
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• 2006

Monolithic molecularly imprinted columns were designed and prepared by an in-situ thermal-initiated copolymerization technique for rapid separation of tryptophan and N- CBZ-phenylalanine enantiomers. The influence of polymerization conditions and separation conditions on the specific molecular recognition ability for enantiomers and diastereomers was investigated. The specious molecular recognition was found to be dependent on the stereo structures and the arrangement of functional groups of the imprinted molecule and the cavities in the molecularly imprinted polymer (MIP). Moreover, hydrogen bonding interactions and hydrophobic interactions played an important role in the retention and separation. Compared to conventional MIP preparation procedures, the present method is very simple, and its macroporous structure has excellent separation properties.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.81-88
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• 2018

The present study evaluated the effective arrangement approach of transverse reinforcement in the jacket section for seismic strengthening of reinforced concrete columns. To simulate the full-scale columns, the section dimensions were determined as $450{\times}450mm$ for non-seismic existing columns and $750{\times}750mm$ for section enlargement strengthening columns. Over-lapped channel-shape bars and prefabricated bar units were proposed for closed-hoops in the jacket section, and conventional cross-ties anchored into existing columns and V-ties were considered for the supplementary ties. Test results showed that the axial capacity of the existing column and section enlargement columns with over-lapped channel-shape hoops was similar to the nominal strength calculated using ACI 318-14 procedure whereas the section enlargement column with prefabricated bar units possessed 1.25 times higher axial capacity than the nominal prediction. Furthermore, the axial ductility ratio of the section enlargement column with prefabricated bar unit was 139% higher than that of the existing column despite the potential size effect on ductility of concrete. Thus, it can be concluded that the developed prefabricated bar unit technique is practically useful for preventing the premature buckling of longitudinal reinforcement and confining core concrete in the section enlargement strengthening columns.

• Communications of Mathematical Education
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• v.24 no.1
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• pp.195-220
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• 2010

The magic square is one of the number arrangements and the sums of each row, column, and diagonal are all equal. The meaning of "方" is "Square". If we don't consider the condition of 'square' then is it possible any number arrangement? There are many special number arrangements such as "magic five number circle(緊五圖)", "magic six number circle(聚六圖)", "magic eight number circle(聚八圖)", "magic nine number circle(攢九圖)", "magic eight camp circle(八陣圖)", "magic nine camp circle(連環圖)" in the ancient Chinese mathematics books such as "楊輝算法", "算法統宗". Also, there is a very special and beautiful number arrangement Jisuguimoondo(地數龜文圖) in the mathematics book "Goosuryak(九數略)" written by Choi suk jung(崔錫鼎) in the Joseon Dynasty. In this study, we introduce a various number arrangements and their properties.

• Journal of architectural history
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• v.25 no.3
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• pp.23-35
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• 2016

The purpose of this study is to classify types of the eaves structure of buildings with the Jusimpo-type structure and to analyze the characteristics of each eaves structure. For this objective, forty buildings were selected and investigated. The results of analysis are summarized as follows. First, the main members of framework which handle a load burden on the long-rafter(長椽) are classified as the Jusim-dori(柱心道里) and the Oemok-dori(外目道里). Based on the method of handling a load, the eaves structure is classified into three types; the Jusim-processing-type(柱心中心形), the Oemok-processing-type(外目中 心形), and the Oemok-processing-variant-type(外目中心變異形). The Jusim-processing-type is the set where the internal length of a long-rafter is longer than the length of the eaves on the basis of the center of a column. The Oemok-processing-type is the set where the external length of a long-rafter is longer than the internal length of it. And the Oemok-processing-variant-type is the set where the internal length of a long-rafter is longer than the external length of it, but it is shorter than the length of the eaves which includes the extruded length of a Buyeon(浮椽). Second, the Jusim-processing-type had been generally adopted in the Jusimpo-type structure of the Goryeo Dynasty. But since the 17th century, the Oemok-processing-type had the highest application rate. Third, the change from the Jusimdori-processing-structure to the Oemokdori-processing-structure means that the long-rafter is moved to the direction of outside of the building, and thus the Jung-dori(中道里) is gradually moved to the column center. And, the change of the eaves with the Jusimpo-type structure was not a process for increasing the length of the eaves but a process for adopting the advantages of the Dapo-type structure by changing the arrangement of purlin. Fourth, the change from the Jusimpo-type structure to the Dapo-type structure could be understood as a process for moving the main point for handling a load from the Jusim-dori to the Oemok-dori.

• Steel and Composite Structures
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• v.31 no.1
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• pp.99-112
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• 2019

Semi-rigid joints have been widely studied in literature in recent decades because they affect greatly the structural response of frames. In literature, the behavior of semi-rigid joints is commonly assumed to be identical under positive and negative moments which are obviously incorrect in many cases where joint details such as bolt arrangement or placement of haunch are vertically asymmetrical. This paper evaluates two common types of steel frames with asymmetrical beam-to-column joints by Direct Analysis allowing for plasticity. A refined design method of steel frames using a proposed simple forth order curved-quartic element with an integrated joint model allowing for asymmetrical geometric joint properties is presented. Furthermore, the ultimate behavior of six types of asymmetrical end-plate connections under positive and negative moment is examined by the Finite Element Method (FEM). The FEM results are further applied to the proposed design method with the curved-quartic element for Direct Analysis of two types of steel frames under dominant gravity or wind load. The ultimate frame behavior under the two different scenarios are examined with respect to their failure modes and considerably different structural performances of the frames were observed when compared with the identical frames designed with the traditional method where symmetrical joints characteristics were assumed. The finding of this research contributes to the design of steel frames as their asymmetrical beam-to-column joints lead to different frame behavior when under positive and negative moment and this aspect should be incorporated in the design and analysis of steel frames. This consideration of asymmetrical joint behavior is recommended to be highlighted in future design codes.

• Steel and Composite Structures
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• v.21 no.2
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• pp.267-287
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• 2016

The seismic performance of the ordinary steel reinforced concrete (SRC) columns has no significant improvement compared to the reinforced concrete (RC) columns mainly because I, H or core cross-shaped steel cannot provide sufficient confinement for core concrete. Two improved SRC columns by constructing with new-type shaped steel were put forward on this background, and they were named as enlarging cross-shaped steel and diagonal cross-shaped steel for short. The seismic behavior and carrying capacity of new-type SRC columns have been researched theoretically and experimentally, while the shear behavior remains unclear when the new-type columns are joined onto SRC beams. This paper presents an experimental study to investigate the shear capacity of new-type SRC joints. For this purpose, four new-type and one ordinary SRC joints under low reversed cyclic loading were tested, and the failure patterns, load-displacement hysteretic curves, joint shear deformation and steel strain were also observed. The ultimate shear force of joint specimens was calculated according to the beam-end counterforce, and effects of steel shape, load angel and structural measures on shear capacity of joints were analyzed. The test results indicate that: (1) the new-type SRC joints display shear failure pattern and has higher shear capacity than the ordinary one; (2) the oblique specimens have good bearing capacity if designed reasonably; and (3) the two proposed construction measures have little effect on the shear capacity of SRC joints embedded with diagonal cross-shaped steel. Based on the mechanism observed from the test, the formulas for calculating ultimate shear capacity considering the main factors (steel web, stirrup and axial compression ratio) were derived, and the calculated results agreed well with the experimental and simulated data.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.109-116
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• 1999

This paper presents an experimental study on the behavior of CFT Column to H-Beam Endplate Connections with penetrated H/T bolts under monotonic loading. The object of this study is to estimate accurately the effect about the thickness of endplate and the arrangement of H/T bolts which was not got a grip on the results reported in the previous paper. Main parameters are the thickness of endplates (12mm, 16mm) and the arrangemement of H/T bolts (EP1, EP2, EP3 Type). The experimental results compared and analysed. 1) The specimens were classified by Bjorhovde's and EC3's method. 2) A formula to predict the ultimate moment of connection was derived based on the T-stub model, and theoretical value $(_tM_u)$ computed by the formula corresponded to the experimental value $(_eM_u)$.