Browsing by Author "Chen, L."

Now showing 1 - 2 of 2

An analytical and experimental study of TLCD for structural vibration control
(2005)
Wang, Y. P.
;
Lee, C. L.
;
Hwu, T. H.
;
Chen, L.
;
土木工程學系
Tuned Liquid Column Damper (TLCD), an integration of vibration control damper with the fire protection hydraulic tank, is considered to be a substitute of the conventional tuned mass dampers (TMD) for vibration control of high-rise buildings. It possesses advantageous features as being easy-tuning, dual-function, maintenance-free and cost-effective. The TLCD system is, in most literature, analyzed as a linear dynamic system by introducing an equivalent viscous damping coefficient related to a constant headloss coefficient and a certain steady-state sloshing amplitude. In this study, the dynamic characteristics of TLCD systems with various orifice sizes have been investigated via component tests using harmonic excitations at various driving frequencies. The headloss coefficients have also been identified with a proposed system identification procedure based on ARX model. It is found that the smaller the opening size, the larger the headloss coefficient; and, the stronger the disturbing amplitude, the smaller the headloss coefficient. In addition, a series of shaking table tests of an aluminum modal frame with and without TLCD has been conducted to verify the effectiveness of adopting TLCD system for structural control. Numerical predictions of the liquid sloshing displacement and structural responses by the proposed analytical model with the experimentally identified headloss coefficient agree very well with the test data, verifying adequacy of the proposed analytical model. Further parametric analysis indicates that the longer the horizontal part the more pronounced the controlling effect. Moreover, if the horizontal portion is restrained due to practical considerations, increasing the tube diameter of the vertical segment may further improve the controlling effect. Finally, the numerical simulation of structural vibration control using TLCD system for Taipei 101 building has also illustrated in this paper.
THE REGISTRATION OF 3-D MODELS AND A 2-D IMAGE USING POINT AND LINE FEATURES
(2010)
Teo, T.
;
Chen, L.
;
土木工程學系
;
Department of Civil Engineering
Space registration of 2-D images and 3-D models is an important task for geoinformation applications. Space registration connects the spatial relationship between the image space and object space. It can be implemented by using different control entities like control points, control lines, control surfaces, etc. 3-D models provide both point and line features. Hence, we establish a procedure to determine the image orientation by integrating these features. The objective of this investigation is to combine the point and linear features in space registration. The proposed scheme utilizes collinearity equations in determining the orientation. In this investigation, we compare three kinds of collinearity equations. The first one is a point-based formulation. The second one is line-based equations. The third one is a collinearity model that combines the point and line features. The test data include a simulation data, an aerial image and a close-range image. The experimental results indicate that the proposed scheme is flexible and reliable.