• Structural Engineering and Mechanics
• /
• v.49 no.2
• /
• pp.147-161
• /
• 2014

In this paper a nonlinear finite element analysis model is established for cold-formed steel zed-section purlins subjected to uplift loading. In the model, the lateral and rotational restraints provided by the sheeting to the purlin are simplified as a lateral rigid restraint imposed at the upper flange-web junction and a rotational spring restraint applied at the mid of the upper flange where the sheeting is fixed. The analyses are performed by considering both geometrical and material nonlinearities. The influences of the rotational spring stiffness and initial geometrical imperfections on the uplift loading capacity of the purlin are investigated numerically. It is found that the rotational spring stiffness has significant influence on the purlin performance. However, the influence of the initial geometric imperfections on the purlin performance is found only in purlins of medium or long length with no or low rotational spring stiffness.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.2
• /
• pp.281-290
• /
• 1994

This paper presents the results of an analytical investigation pertaining to the compression behavior of axially loaded plates made from pultruded fiber reinforced plastic materials. Non-dimensionalized closed-form solutions have been developed for the prediction of the buckling load in the pultruded plates with edge stiffener. These solutions were based upon the classical theory of orthotropic plates and accounted for the e1astic restraints at the juncture of plate and stiffener. The effects of edge stiffener on the flange plate were investigated in order to clarify its usefulness for increasing flange local buckling load of the pultruded structural shapes.

• International Commerce and Information Review
• /
• v.5 no.1
• /
• pp.63-83
• /
• 2003

This paper's objective is to provide insights about the problems and expansion strategies of electronic trade. Korean small and medium-sized firms have adopted the Internet since the end of 1990s in order to reshape their competitiveness, and it is now being utilized as a major export marketing instrument to develop new customers, save export transaction costs ad facilitate new work processes. However, at present, the use of the internet in the field of trading is limited to the collection of market information, owing to legal, technical and institutional restraints between countries. In addition to that, because firms have the difficulties in making the trade contract through the e-trade system, the negative recognition on its' utility has been spreaded gradually between companies. This is one of the barriers to block the expansion of e-Trade between Korean firms. Therefore, this paper points out the problems of e-trade in the environmental, institutional and strategic view and provides many considerations for establishing the expansion strategy of e-trade by the Korean government and trade supporting institutions.

• Steel and Composite Structures
• /
• v.21 no.1
• /
• pp.37-55
• /
• 2016

In this study, the influence of centrally placed circular and square cutouts on vibration and buckling characteristics of different ply-oriented laminated panels under the action of compressive and/or tensile types of non-uniform in-plane edge loads are investigated. The panels are inspected under the action of uniaxial compression, uniaxial tension and biaxial, compression-tension, loading configurations. Furthermore, the effects of different degrees of edge restraints and panel aspect ratios are also addressed in this work. Towards this, a nine-node heterosis plate element has been adopted which includes the effect of shear deformation and rotary inertia. According to the results, the tensile buckling loads are higher than that of compressive buckling loads. However, the tensile buckling load continuously reduces with the increased cutout sizes irrespective of ply-orientations. This is also true for compressive buckling loads except for some particular ply-orientations with higher sized cutouts.

• Structural Engineering and Mechanics
• /
• v.55 no.3
• /
• pp.605-638
• /
• 2015

It is intended to perform buckling analysis of steel gabled frames with tapered members and flexible connections. The method is based on the exact solutions of the governing differential equations for stability of a gabled frame with I-section elements. Corresponding buckling load and subsequently effective length factor are obtained for practical use. For several popular frames, the influences of the shape factor, taper ratio, span ratio, flexibility of connections and elastic rotational and translational restraints on the critical load, and corresponding equivalent effective length coefficient are studied. Some of the outcomes are compared against available solutions, demonstrating the accuracy, efficiency and capabilities of the presented approach.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.2 no.2
• /
• pp.153-155
• /
• 2006

Many patients with mental retardation need extensive dental treatment because they have much difficulty in maintaining their oral hygiene. However, because they are not cooperative and not manageable, they require physical restraints, drug induced sedation or general anesthesia. General anesthesia is useful in control of the patients who cannot be treated in other ways. Additionally, general anesthesia provides more safe environment for medically compromised patients. And medical treatment can be provided simultaneously under general anesthesia. Furthermore, almost all treatment can be provided without visiting several times. This case reports of periodontal, restorative and ophthalmological treatment of patient with mental retardation under general anesthesia.

• Journal of the Korean Society of Safety
• /
• v.14 no.2
• /
• pp.32-41
• /
• 1999

If the Leak-Before-Break (LBB) concept is applicable to the nuclear piping design, it is not necessary to consider the dynamic effect due to pipe rupture. Therefore, the construction cost can be significantly reduced by eliminating unnecessary pipe whip restraints and jet impingement devices. The objective of this paper is to develop the Piping Evaluation Diagram (PED) for efficient application of LBB concept to piping system at an initial piping design stage. For this purpose, the 3-D finite element analyses were performed to evaluate the crack stability. And the stress-strain curve based on the pipe material tests were used to calculate the detectable leakage crack length. Finally, the present PED which was composed as a function of NOP load and allowable SSE load, was developed for an application of LBB concept to the safety injection and shutdown cooling line in Korean Next Generation Reactor (KNGR).

• Journal of the Korean Magnetic Resonance Society
• /
• v.15 no.1
• /
• pp.80-89
• /
• 2011

3D structures of STAM1 UIM-ubiquitin complex were presented to predict and analyze the interaction between UIM and ubiquitin. To generate the protein-peptide complex structure, the RosettaDock method was used with and without NMR restraints. High resolution complex structure was acquired successfully and evaluated electrostatic interaction in the protein-peptide binding with several charged residues at the binding site. From docking results, the Rosettadock method could be useful to acquire essential information of protein-protein or protein-peptide interaction with minimal biological evidences.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.10 no.4
• /
• pp.11-24
• /
• 1990

The effect of end restraints for adjoining members is the different variables influencing the column ultimate strength and the behavior. The propose of this study is to analyze eccentrically loaded reinforced concrete columns with the end restraind effect having rectangular cross-section and general boundary conditions. Accordingly, this investigation are to construct a typical analytical model of the reinforced concrete columns with general end boundary conditions. The mechanical components of the analytical model are to be rationally defined the actual behavior as possible, and the different variables influencing the behavior and the ultimate strength of the reinforced concrete columns are investigated by using a parametric study.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.903-908
• /
• 2007

A retractor is the major component of a seatbelt system that restraints passengers by locking the movement of webbing. Recently, in order to increase the effectiveness of seatbelt systems, motorized retractors that remove slack and correct passenger posture just before airbag expansion when collision is predicted are widely used. Key component of motorized retractors is the one-way clutch that engages and disengages the winding action of webbing according to the direction of motor revolution. Analytical investigation of action of the one-way clutch mechanism has been carried out to figure out conditions for one-way locking, and to study the effect of various kinematic and dynamic design variables of one-way clutch. Using combination of ADAMS and LifeMOD soft-wares, dynamic simulation of operation of motorized retractors including Hybrid-III dummy model has been carried out to evaluate the performance of the motorized retractors in various crash scenarios.