• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.4
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• pp.231-237
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• 1999

A geometric non-linear finite element formulation of spatial ocean cable under currents is presented using multiple noded curved cable elements. Tangent stiffness and mass matrices for the isoparametric cable ele¬ment are derived and the initial equilibrium state of ocean cable subjected to self-weights, buoyancy, and current as well as support motions is determined using the load incremental method. Free vibration analysis of ocean cables is performed based on the initial equilibrium configuration. Numerical examples are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate dynamic characteristics of ocean cables.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1656-1662
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• 2011

In a previous paper, the EMTP modeling technique using search coil test is established through various transient analysis including system grounding condition and grounding resistance for HVDC submarine cables. It was also proved by comparison with real test results. Based on this EMTP modeling technique, in this paper, it will be applied for modeling of ${\pm}180kV$ real HVDC submarine system(Jeju~Haenam). This paper variously analyses the effects of fault resistance including the resistance between core and sheath, the resistance between sheath and amore and the resistance between amore and sea water through EMTP modeling of search coil method. The results can contribute to the accuracy of detailed fault point prediction of search coil test for HVDC submarine cables.

• Structural Engineering and Mechanics
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• v.51 no.1
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• pp.141-162
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• 2014

The paper focuses on the dynamic response of a blast-invested glass-steel curtain wall supported by single-way pretensioned cables. In order to mitigate the critical components of the façade from severe structural damage, an innovative system able to absorb and dissipate part of the blast-induced stresses in the critical façade components is proposed. To improve the blast reliability of the studied glazing system, specifically, rigid-plastic and elastoplastic devices are introduced at the base and at the top of the vertical bearing cables. Several combinations and mechanical calibrations of these devices are numerically investigated and the most structurally and economically advantageous solution is identified. In conclusion, a simple analytical formulation totally derived from energetic considerations is also suggested for a preliminary estimation of the maximum dynamic effects in single-way cable-supported façades subjected to high-level blast loads.

• Wind and Structures
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• v.10 no.1
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• pp.83-97
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• 2007

In the last decades there have been frequent reports of oscillations of slender tension members under simultaneous action of rain and wind - characterized by large amplitudes and low frequencies. The members, e.g. cables of cable-stayed bridges, slightly inclined hangers of arch bridges or cables of guyed-masts, show a circular cross section and low damping. These rain-wind induced vibrations negatively affect the serviceability and the lifespan of the structures. The present article gives a short literature review, describes a mathematical approach for the simulation of rain-wind induced vibrations, sums up some examples to verify the calculated results and discusses measures to suppress the vibrations.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.15-38
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• 2018

Negative stiffness dampers (NSDs) have been proven an efficient solution to vibration control of stay cables. Although previous studies usually assumed a linear negative stiffness behavior of NSDs, many negative stiffness devices produce negative stiffness with nonlinear behavior. This paper systematically evaluates the impact of nonlinearity in negative stiffness on vibration control performance for stay cables. A linearization method based on energy equivalent principle is proposed, and subsequently, the impact of two types of nonlinear stiffness, namely, displacement hardening and softening stiffness, is evaluated. Through the Hilbert transform (HT) of free vibration responses, the effects of nonlinear stiffness of an NSD on the modal frequencies, damping ratios and frequency response functions of a stay cable is also investigated. The HT analysis results validate the accuracy of the linearization method.

• Structural Engineering and Mechanics
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• v.16 no.1
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• pp.1-15
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• 2003

This paper proposes a new method for the preliminary design of cable-stayed bridges that belong to the radial system subjected to static loads (self weight, traffic loads, concentrated loads, etc). The method is based on the determination of the each time existing relation between the tension forces of the cables and the corresponding bridge-deck deformations, and can be extended on any type of cable layout (fan, parallel, or mixed system). Galerkin's method is used for the final determination of the cable stresses and the bridge deformation. The determination of the equation, which gives the forces of the cables in relation to the deck's configurations, permits us to convert the problem to the solving of a continuous beam without cables.

• Wind and Structures
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• v.11 no.5
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• pp.391-411
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• 2008

A design procedure of stabilizing cable is proposed using buffeting analysis to stabilize the seesaw-like motion of the free cantilevered structure of a cable-stayed bridge during its construction. The bridge examined is a composite cable-stayed bridge having a main span length of 500 m. Based on the buffeting analysis, the stress in bare structure exceeded the allowable limit and a set of stabilizing cable was planned to mitigate the responses. The most efficient positions of the hold-down stabilizing cables were numerically investigated by means of an FE-based buffeting analysis and the required dimensions and pretension of the stabilizing cables were also calculated. The proposed stabilizing measure would be expected to secure the aerodynamic safety of a cantilevered structure under construction with considerable mitigation of buffeting responses.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.300-301
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• 2006

Korean power system has some problems like as curtailing investment and the NIMBY (Not In My Back Yard) phenomena, because of power demand concentration in downtown area. In this time, superconducting power devices rise as a very attractive solution. This study proposes a basic concept of superconductivity power system with bulk capacity, and identifies the items for technical and economic analysis. The proposed system consists of superconducting cables/transformers/FCLs(fault current limiter). The basic concept is to replace 154kV conventional cables with 22.9kV superconducting cables and to convert a 154kV substation into a 22.9kV switching station in downtown area.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.399-401
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• 2005

When power cables cross regions with unfavorable thermal conditions, conductor temperatures higher than the design value can occur. This paper proposes the calculation algorithms of the permissible current-carrying capability of dissimilar power cables installed in thermally dissimilar soil materials.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.77-78
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• 2009

This study is to consider the character of cables in six World-Cup stadiums constructed in 2002 in Korea and to inspect problem on application of existing theory. The result of experiment shows that it is possible to determine the tension force of the real cables with an accuracy of 10${\sim}$60 by taking the cable bending stiffness. However, the reliance of the tension force experimentally determined could be changed in tension in the cable.