• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.101-109
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• 2018

Modular structural systems have been used increasingly for low- and mid-rise structures such as school and apartment buildings. Studies have recently been conducted on the application of the modular structural system to high-rise buildings. To provide sufficient resistances and economical construction for the high-rise modular structural system, a composite unit modular structure was proposed. In this study, the strength of the non-symmetric composite column for the proposed composite unit modular structure was investigated through a series of tests. The experimental study focused on the effect of the slenderness of the column, eccentricity, and through bars on the strength of such a column. Design equations for the non-symmetric column for a modular unit structure were also proposed. From the results, it was found that the proposed design equations provide reasonable strength prediction of the non-symmetric composite column for the modular unit structure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.1-9
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• 2014

Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. In this study, a non-compression cross-bracing system using the Carbon Fiber Composite Cable (CFCC), which consists of CFCC bracing and bolt connection was proposed to replace the conventional steel bracing. This paper presented the seismic resistance of a reinforced concrete frame strengthened using CFCC X-bracing. Cyclic loading tests were carried out, and the maximum load carrying capacity and ductility were investigated, together with hysteresis of the lateral load-drift relations. Test results revealed that the CFCC X-bracing system installed RC frames enhanced markedly the strength capacity and no buckling failure of the bracing was observed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.427-434
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• 2017

Recently, awareness of the public about the explosion damage has increased due to the increased risk of terrorism. The criteria for blast-resistance design is not sufficient in Korea, it is necessary to develop blast-resistance design for the stability and safety of building by static analysis of current blast-resistance design. In addition, as the increase of earthquake occurrence necessitates the seismic design, it is studied to judge the blast-resistance performance of members applying seismic design without blast-resistance design. Currently, the general analysis of blast load is to refer to UFC 3-340-02 manual. Blast-resistance performance was studied by applying characteristics of blast load through UFC 3-340-02 manual, beam converted into equivalent SDOF System. It is proved that blast-resistance performance is improved when seismic detail is applied considering the maximum deflection of normal, intermediate, and special moment frames.

• Korean Journal of Social Welfare
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• v.56 no.4
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• pp.195-214
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• 2004

As one of the essential elements of social work practice, knowledge articulates what the social work profession is doing and ought to do. With an emphasis on building a body of knowledge for the profession, this study analyses the nature of social work knowledge. First, the study examines concepts of social work theories and models, which are built around separate clusters of concepts from a broad base of theoretical orientation. The study reviews epistemological and ideological debates over how to perceive and approach social issues and the role of the social work profession. In organizing a clear conceptual framework for social work practice, different frames of reference and selective and fragmentary knowledge from other disciplines are considered barriers. For the development of a clear identity as a unified profession and the prospects of a value-based profession, more attention needs to be given to specify practical knowledge that is contextual and appropriate to practice settings and more sensitive to social issues.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.3
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• pp.441-451
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• 2002

Recently, Increasing residential-commercial buildings are composed of upper wall and lower frame type. As structural fragility, a large numbers of researchers have tried to develope the efficient analysis methods. But these studies were too theoretical and were not considered the lateral load which was required in analysing the transfer level in addition to being used nonlinear program which was difficult to use for practical design. thus, results of these studies we not appropriate to apply practical design, therefore, in this paper, the procedure of the current design practice were compared with that of used FEM method and presented new modeling method. in particular, an efficient analytical model which can be used in practical design of residential-commercial buildings for vortical and seismic loads was proposed and the usefulness of proposed model was verified.

• Wind and Structures
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• v.10 no.3
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• pp.233-247
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• 2007

The insertion of steel braces has become a common technique to limit the deformability of steel framed buildings subjected to wind loads. However, when this technique is inadequate to keep floor accelerations within acceptable levels of human comfort, dampers placed in series with the steel braces can be adopted. To check the effectiveness of braces equipped with viscoelastic (VEDs) or friction dampers (FRDs), a numerical investigation is carried out focusing attention on a three-bay fifteen-storey steel framed building with K-braces. More precisely, three alternative structural solutions are examined for the purpose of controlling wind-induced vibrations: the insertion of additional diagonal braces; the insertion of additional diagonal braces equipped with dampers; the insertion of both additional diagonal braces and dampers supported by the existing K-braces. Additional braces and dampers are designed according to a simplified procedure based on a proportional stiffness criterion. A dynamic analysis is carried out in the time domain using a step-by-step initial-stress-like iterative procedure. Along-wind loads are considered at each storey assuming the time histories of the wind velocity, for a return period $T_r=5$ years, according to an equivalent wind spectrum technique. The behaviour of the structural members, except dampers, is assumed linear elastic. A VED and an FRD are idealized by a six-element generalized model and a bilinear (rigid-plastic) model, respectively. The results show that the structure with damped additional braces can be considered, among those examined, the most effective to control vibrations due to wind, particularly the floor accelerations. Moreover, once the stiffness of the additional braces is selected, the VEDs are slightly more efficient than the FRDs, because they, unlike the FRDs, dissipate energy also for small amplitude vibrations.

• Steel and Composite Structures
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• v.34 no.1
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• pp.107-122
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• 2020

Moment resisting stub columns (MRSCs) have increasingly adopted in special moment-resisting frame (SMF) systems in steel building structures, especially in Asian countries. The MRSCs typically provide a lower deformation capacity compared to shear-panel stub columns, a limited post-yield stiffness, and severe strength degradation as adopting slender webs. A new MRSC design with cored configuration, consisting of a core-segment and two side-segments using different steel grades, has been proposed in the study to improve the demerits mentioned above. Several full-scale components of the cored MRSC were experimentally investigated focusing on the hysteretic performance of plastic hinges at the ends. The effects of the depths of the core-segment and the adopted reduced column section details on the hysteretic behavior of the components were examined. The measured hysteretic responses verified that the cored MRSC enabled to provide early yielding, great ductility and energy dissipation, enhanced post-yield stiffness and limited strength degradation due to local buckling of flanges. A parametric study upon the dimensions of the cored MRSC was then conducted using numerical discrete model validated by the measured responses. Finally, a set of model equations were established based on the results of the parametric analysis to accurately estimate strength backbone curves of the cored MRSCs under increasing-amplitude cyclic loadings.

• Steel and Composite Structures
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• v.37 no.2
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• pp.175-191
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• 2020

In this article, for the first time, the seismic behavior of elliptic-braced moment resisting frame (ELBRF) is assessed through a laboratory program and numerical analyses of FEM specifically focused on the development of global- and local-type failure mechanisms. The ELBRF as a new lateral braced system, when installed in the middle bay of the frames in the facade of a building, not only causes no problem to the opening space of the facade, but also improves the structural behavior. Quantitative and qualitative investigations were pursued to find out how elliptic braces would affect the failure mechanism of ELBRF structures exposed to seismic action as a nonlinear process. To this aim, an experimental test of a ½ scale single-story single-bay ELBRF specimen under cyclic quasi-static loading was run and the results were compared with those for X-bracing, knee-bracing, K-bracing, and diamond-bracing systems in a story base model. Nonlinear FEM analyses were carried out to evaluate failure mechanism, yield order of components, distribution of plasticity, degradation of structural nonlinear stiffness, distribution of internal forces, and energy dissipation capacity. The test results indicated that the yield of elliptic braces would delay the failure mode of adjacent elliptic columns and thus, help tolerate a significant nonlinear deformation to the point of ultimate failure. Symmetrical behavior, high energy absorption, appropriate stiffness, and high ductility in comparison with the conventional systems are some of the advantages of the proposed system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1053-1059
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• 2011

DMX512 protocol is a typical protocol which controls LED lighting system. It has a strong feature and can be used to a lot of lighting system. But LED control system with cable has a few problem because they have a lot of control cables. It is very difficult to set up the complex lighting. Furthermore if it is set up it is not easy to keep and recover the system from the out of order. So it is required Wireless Lighting Control System. This paper describes the proposal, design, and implementation of a novel method which can provide versatile light effects with the increased capability of the mobility and the number of universes for Wireless Lighting system. And then we implement experiment environment to control indoor lighting system controled by ZigBee and WLAN converter not having complicating control line. Data frames are transferred to DMX512 device by encapsulation and decapsulation to control color LED. In the same time give the method to solve the data bottleneck problem which can be comes out because of speed difference between Heterogeneous network and measure performance of control system.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.994-1009
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• 2016

Applying the S-O-R Model within an online context, a hypothesized model incorporates three review characteristics (perceived concreteness, exaggeration, and sufficient quantity of reviews) for apparel products in order to present their impact on consumer perceptions of review usefulness and consumer attitude toward and patronage intent for the online stores hosting the reviews. An online survey of Korean women (N=299) reported their experiences in purchasing apparel products online and reading apparel reviews on a regular basis. Testing of the hypothesized model showed the usefulness of reviews were determined by two review characteristics (S: perceived concreteness and sufficient quantity of reviews); however, the negative effect of exaggerated reviews were insignificant. In addition, the perceived usefulness of reviews (O-cognitive) hosted by an online store influenced online store attitude (O-affective) which subsequently led to online store patronage intent (R). This study systemically advances online retail literature by showing how the characteristics of online reviews (as a part of the online store environment) can influence attitude toward online stores and patronage intent for online stores. Long term relationships with consumers can be achieved through the building of mechanisms to enhance the perceived usefulness of reviews by employing the strategies of hosting concrete reviews and offering a sufficient quantity of reviews. This study addresses removes research gaps by testing an adapted the S-O-R Model that frames review information as an element of an online store environment using a large sample.