• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.83-84
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• 2014

The whole wall system behaves as one section because single walls composing irregular wall are connected to each other. Although stress of a single wall is affected to the connected wall under lateral load, the stress is not transferred to whole sections and is concentrated on particular part of the wall as well. Therefore these walls can be divided into the effective and ineffective section. The purpose of this study is to compare design result of irregular wall using codes and previous studies on an effective width of the wall and to analyze reduction of the longitudinal bar of irregular wall.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.113-119
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• 1998

This study is focused on evaluation of the structural behavior of skewed bridge during earthquake. The variation of natural frequencies and the lateral forces at pier shoes by the skewness and the rotational effect about vertical axis of skewed bridge due to seismic activity are analytically evaluated and identified through case studies. For this purpose, the composite steel girder highway bridges are selected as case study models. The seismic analyses by response spectrum method and time history method are performed for the selected models. It has been recognized that the frequency of longitudinal model increased as the skew angle decreased, while the lateral mode frequency showed the opposite trends. When the skew angle decreased, longitudina seismic forces of the bridge at the pier were increased but decreased in transverse direction. And it also has been found that the skewed bridges of the case study models showed the rotational behavior about vertical axis due to motion of San Fernando earthquake at Pacoima Dam.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.1-27
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• 2015

This article presents a theoretical parametric analysis on the ultimate torsional behaviour of axially restrained reinforced concrete (RC) beams. This analysis is performed by using a computing procedure based on a modification of the Variable Angle Truss Model. This computing procedure was previously developed to account for the influence of the longitudinal compressive stress state due to the axial restraint conditions provided by the connections of the beams to other structural members. The presented parametric study aims to check the influence of some important variable studies, namely: torsional reinforcement ratio, compressive concrete strength and axial restraint level. From the results of this parametric study, nonlinear regression analyses are performed and some design charts are proposed. Such charts allow to correct the resistance torque of RC beams (rectangular sections with small height to width ratios) to account for the favorable influence of the axial restraint.

• Earthquakes and Structures
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• v.7 no.5
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• pp.861-875
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• 2014

This paper studies the response of seismic behavior of reinforced concrete exterior beam-column joints under reversal loading with different anchorages and joint core details. The joint core was detailed without much confinement (group-I) and/or with proposed X-cross bars in the core (group-II). The beam longitudinal reinforcement's anchorages were designed as per ACI 352 (headed bars), ACI 318 (conventional $90^{\circ}$ bent hooks) and IS 456 ($90^{\circ}$ bent hooks with extended tails). The nonlinear finite element analysis response of the beam-column joints was studied, along with initial and progressive cracks up to failure. The experimental and analytical results were compared and presented in this paper to make more scientific conclusions.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.399-408
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• 2015

This paper concentrated on the ultimate uniaxial compressive strength of stiffened panel with opening under lateral load and also studied the design-oriented formulae. For this purpose, three series of well executed experiments on longitudinal stiffened panel with rectangular opening subjected to the combined load have been selected as test models. The finite element analysis package, ABAQUS, is used for simulation with considering the large elasticplastic deflection behavior of stiffened panels. The feasibility of the numerical procedure is verified by a good agreement of experimental results and numerical results. More cases studies are executed employing nonlinear finite element method to analyze the influence of design variables on the ultimate strength of stiffened panel with opening under combined pressure. Based on data, two design formulae corresponding to different opening types are fitted, and accuracy of them is illustrated to demonstrate that they could be applied to basic design of practical engineering structure.

• Bulletin of the Society of Naval Architects of Korea
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• v.23 no.4
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• pp.1-10
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• 1986

A container ship, due to wide hatch openings, has characteristics of poor torsional rigidity, strong coupling of horizontal-torsional modes and significant discontinuity in the longitudinal variation of hull sections. In the mathematical formulation of the problem the hull is modeled as a beam and the transfer matrix method is utilized. The cross decks between cargo hatch opening are separated from the main hull and regarded as equivalent springs restraining torsion of hull. The effect of shear deformation of ship-side plating on torsion is taken into account in addition to St. Venant's and bending torsional rigidities. Compatibility requirements at cross section discontinuity are approximately considered. Developing the practical calculation procedure and the computer programs for application to an actual ship, some parametric studies on modeling methods of the cross deck, the compatibility condition, added-mass center etc. are out for the purpose of comparison.

• International Journal of Railway
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• v.3 no.4
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• pp.126-133
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• 2010

The thermal buckling analysis of curved continuous welded rail (CWR) is studied for the lateral buckling prevention. This study includes a thermal buckling theory which accounts for both thermal and vehicle loading effects in the evaluation of track stability. The parameters include rail size, track lateral resistance, track longitudinal and torsional stiffnesses, initial misalignment amplitude and wavelength, track curvature, tie-ballast friction coefficient and truck center spacing. Parametric studies are performed to evaluate the effects of the individual parameters on the upper and lower critical buckling temperatures. The results show that the upper critical buckling temperature is highly affected by the uplift due to vehicle loads. This study provides a guideline for the improvement of stability for dynamic buckling in curved CWR track.

• Research in Community and Public Health Nursing
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• v.17 no.3
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• pp.346-353
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• 2006

Purpose: The Purpose of this study was to analyze factors influencing the dependence of the elderly. Method: This research was designed as a descriptive study. The subjects were 103 elders living in Seoul. Data were collected from December 2004 through January 2005. The instrument used in this study was the elderly dependence scale developed by the Park (2004). Collected data were analyzed using SPSS 11.0 for Windows. Descriptive statistics, independent t-test, ANOVA and multiple regression were done. Results: In the results of regression, residence, education, vision and age were extracted as factors influencing the dependence of the elderly. The regression model explained 33% of the variance. Conclusion: Considering the results above, we need studies on the dependence of the elderly using more independent variables, on the changing pattern of dependence and influencing factors by longitudinal design, and on the elderly with functional limitations or cognitive impairment.

• Journal of the Korean Data and Information Science Society
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• v.25 no.5
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• pp.1117-1125
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• 2014

In a longitudinal study, subjects can experience same type of events repeatedly. Also, there may exist intermittent dropouts resulting in repeated observation gaps during which no recurrent events are observed. Furthermore, when such observation gaps have incomplete forms caused by the unknown termination times of observation gaps, ordinary approaches result in biased estimates. In this study, we investigate the effect of ignoring observation gaps and propose methods to overcome this problem. For estimating the distribution of unknown termination times, an interval-censored mechanism is applied and two cases are considered. Simulation studies are carried out to evaluate the performance of the proposed method. Conviction data of young drivers with several suspensions are analyzed to illustrate the suggested approach.

• Journal of Welding and Joining
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• v.31 no.6
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• pp.107-111
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• 2013

The welding distortion is caused by welding heat in the structures which are widely used in shipbuilding and automotive industries, thus many researchers have proposed such methods to control the welding distortion through trials and numerical studies. The welding distortion has been the main cause of low productivity due to the structural strength degradation, apparent flaw, additional deformation caused by the process followed the current assembly step, and the increase of correction workload. The deformation of fillet welding is investigated in this study, and the influence of the rib height on the welding distortion is verified through the actual experiment. And the numerical analysis model using the FE software MSC.marc for analysis of welding distortion is proposed.