• Communications of the Korean Mathematical Society
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• v.7 no.1
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• pp.81-84
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• 1992

• Structural Engineering and Mechanics
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• v.4 no.4
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• pp.462-465
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• 1996

• The Safety technology
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• no.54
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• pp.64-69
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• 2002

• Structural Engineering and Mechanics
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• v.7 no.2
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• pp.217-224
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• 1999

A semi-stochastic process model of reliability was established for hyperbolic cooling towers subjected to combined loadings of wind force, self-weight, temperature loading. Effect of the soil-structure interaction on reliability was evaluated. By involving the gust factor, an equivalent static scheme was employed to convert the dynamic model to static model. The TR combination rule was used to consider relations between load responses. An analysis example was made on the 90M cooling tower of Maoming, Guangdong of China. Numerical results show that the design not including interaction turns to be conservative.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.3
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• pp.133-138
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• 2005

This paper presents a characteristics of horizontal swing angle in V type suspension string sets for 765kV T/L. The design of V type suspension string set does not differ from that of general string set for general towers, but it prevents instabilities from swing motion by the horizontal angle and by the wind pressure. We were designed specially 6 conductor yoke, arcing horn and earth horn. And we were decided to 550mm for a distance of strings. We were carried out characteristics of horizontal swing test and movement of mass center test for V-string sets of 400kN single, 300kN double and 400kN double. This products will be used for 765kV T/L of 1 circuit in suspension towers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.381-388
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• 1988

The heights of the towers of a ropeway are theoretically derived and the result is experimentally verified. The accuracy in the equation of deflection angle obtained by applying the characteristics of catenary curve was confirmed through experiment. By applying these equations the optimal values of the tower heights could be obtained because the deflection angles trade off each other. The deflection angle was measured by using the curve fitting technique.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.151-158
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• 2005

An important component of a cooling tower is an axial fan, and there happens distortion in its shape which brings significant loss of efficiency. In this paper, a surface profile measuring system for large size axial fan of cooling towers is developed. A laser sensor is used as a measuring device and aluminum profiles and stepping motors are engaged into the system as frame structure and driving devices respectively. The measuring data are compared to the design data to compute the distortion of the axial fans. Two types of errors, axial and twist errors, are used to represent the precision of axial fan distortion. Genetic algorithm is used to solve the optimization problem during computing the precision. Results are displayed three dimensionally in a solid-modeler as well as 2-D drawings to help users find it with ease.

• Wind and Structures
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• v.4 no.1
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• pp.63-72
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• 2001

This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

• Structural Engineering and Mechanics
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• v.6 no.5
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• pp.555-569
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• 1998

The reliability of antenna tower designed for a n-year design wind speed is determined by considering the variability of the strength of the component members and of the mean wind speed. For obtaining the n-year design wind speed, maximum annual wind speed is assumed to follow Gumbel Type-1 distribution. Following this distribution of the wind speed, the mean and standard deviation of stresses in each component member are worked out. The variability of the strength of members is defined by means of the nominal strength and a coefficient of variation. The probability of failure of the critical members of tower is determined by the first order second moment method (FOSM) of reliability analysis. Using the above method, the reliability against allowable stress failure of the critical members as well as the system reliabilities for a 75 m tall antenna tower, designed for n-year design wind speed, are presented.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.1
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• pp.88-94
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• 1998

The thermal performance of cooling towers is affected mainly by the velocity, temperature and humidity of the entering air, In this paper, the effects of these variables are experimentally investigated for both counter-flow and cross-flow cooling towers. The cooling performance is reduced by up to 50% as the relative humidity of the entering air is increased from 40% to 80%. The higher air velocity and lower coolant flow show better cooling performance. The coolant loss rates in the present experimental conditions are in the range of 0.4 to 1.7%