• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.177-183
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• 2010

Overhead transmission lines in domestic area have been built by several different design standards of dip and ground clearance. This paper describes an experimental study for evaluating load capacity and dip margin in overhead transmission lines. Such design standards for selection of overhead transmission conductors, dip and ground clearance, as well as electrical equipment technical standard are discussed. Based on daily load and weather data, several characteristics such as line utilization factor, load factor, conductor temperature and dip, etc. are analyzed, and compared with the specified levels of design standards. As a result, it is verified that DLR method can be a clue of the solving of the problem, for occurring in old transmission conductors which may be rarely operating below standards.

• Journal of IKEEE
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• v.16 no.1
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• pp.1-6
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• 2012

Thermal rating or lifetime evaluation for aged overhead transmission line becomes more important concerns with respect to keeping power delivery stable having proper capability. Both load rating and dip/clearance are essential factors to determine transmission capacity. In order to evaluate thermal rating and conductor lifetime for domestic transmission lines with double-circuit, the dip/ground clearance standards as well as the electrical equipment technical standard are examined. Conductor temperature and dip are calculated under the assumption of a contingency, and then, a method to up-rate load capacity is searched. As thermal rating and limit dip for aged conductor are properly evaluated, an improved strategy in order to guarantee the existing power system reliability is presented in this paper.

• Journal of Power System Engineering
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• v.5 no.3
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• pp.56-63
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• 2001

A slitter is a sort of machinery to cut sheet materials in rolls continuously in the longitudinal direction. Recently slitter line users have requiring higher quality and precision in products in addition to high productivity. A finite element analysis has been performed to investigate the effect of processing factors on shear planes in the slitting of Shrinkage Band(S,K.B.). For the analysis, Hot-dip 55% aluminum-zinc alloy-coated steel sheets and coils(SAZCC) is selected as a material. The results obtained are that deformation was concentrated along the very narrow zone and the maximum slitting load decreases by increasing the knife clearance. Also effective strain decreases according to the clearance increases.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.112-119
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• 2007

Under normal operating condition, the conductor of overhead transmission line could be always hold it's clearance within the safety margin that is specified in the line design guide of power company. Hence it may be very important to measure/or monitor the dip of the conductor, when building a new line, re-tensioning for an aged conductor, or monitoring dynamic line rating to maximize power capability. In this paper, we suggest a new method to estimate the dip and tension by catenary angle of the conductor. Since most conductors in overhead transmission lines show typical catenary curves, it can be uniquely determined the catenary curve for the conductor from the catenary angle at tower. Based on the catenary curve, the dip or horizontal tension can be easily estimated. Through some simulation and simple experimental results, it is verified that the suggested method can be effectively applied to measure/or monitor conductor dips and tensions in the overhead transmission lines.

• The Korean Journal of Pharmacology
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• v.25 no.1
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• pp.101-107
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• 1989

To evaluate disposition characteristics of procainamide and its active metabolite, N-acetylprocainamide (NAPA), cross-over study for procainamide and NAPA was performed in 5 male adult dogs. After single administration of 10 mg/kg procainamide over 15 minutes, the range of measured plasma NAPA concentrations during experimental period were 0.03 to 0.124 ug/ml and early 'dip' phenomenon was distinct on NAPA concentration to time curve in all 5 dogs. Volume of distribution (Vss) and central compartment volume (Vc) of procainamide were $1.20{\pm}0.27\;L/kg$ of body weight and $0.36{\pm}0.08\;L/kg$, respectively. Vss and Vc of NAPA were $1.21{\pm}0.21\;L/kg$ and $0.26{\pm}0.07\;L/kg$, respectively. Intercompartmental clearance (Clint) of procainamide was 3.44 L/kg/hr and that of NAPA was 1.62 L/kg/hr. Total body clearance (Cl) of procainamide and NAPA were $0.47{\pm}0.08$ and $0.35{\pm}0.08\;L/kg/hr$. The half-life $(t_{1/2{\beta}})$ of procainamide and NAPA were 2.85 hrs and 2.77 hrs, respectively. Metabolic clearance (Clm)of procainamide by N-acetylation was $18.24{\pm}6.22\;ml/kg/hr$, which corresponded to 3.9% of total procainamide clearance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.20-28
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• 2007

This paper describes an analytical method to determine the short-term ratings to reliably operate the overhead transmission lines with double-circuit lines when faulting one circuit of the two. As linearizing the thermal equilibrium equation that represents the temperature characteristic of conductors, we show that the linear equation can be easily represented the over-current and it's temperature property during overloading the one line. Generally, it is well hewn that the short-term line ratings should be determined by considering both conductor life and dip. However, most power companies have their own different guides for the short-term ratings. Using the suggested method in this paper, it can be re-accessed the short-term ratings given in Kepco's overhead transmission lines constructed during the past three different periods. As a result, it is verified that the short-term ratings could be increased mil efficiently. Furthermore, it would be directly applied the given method to determine the short-term dynamic line ratings when occurring faults in one of the double-circuit lines, without doing my other actions for the current lines.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.253-270
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• 2013

This paper concerns the effect of orientation and geometric characteristics of a fracture zone on the tunnel behavior using a numerical investigation. A parametric study was executed on a number of drill and blast tunnelling cases representing different fracture and tunnelling conditions using two and three dimensional finite element analyses. The variables considered include the strike and dip angle of fracture zone relative to the longitudinal tunnel axis, the width and the clearance of the fracture zone, the tunnel depth, and the initial lateral stress coefficient. The results of the analyses were examined in terms of the tunnel deformation including crown settlement, convergence, and invert heave as well as shotcrete lining stresses. The results indicate that the tunnel deformation as well as the shotcrete lining stress are strongly influenced by the orientation of the fracture zone, and that such a trend becomes more pronounced for tunnels with greater depths.