A new algorithm called the weighted least square discrete parameterization (WLSDP) is presented for the parameterization of triangular meshes over a convex planar region. This algorithm is the linear combination of th...A new algorithm called the weighted least square discrete parameterization (WLSDP) is presented for the parameterization of triangular meshes over a convex planar region. This algorithm is the linear combination of the discrete Conformal mapping(DCM) and the discrete Authalic mapping(DAM). It provides the good properties of both DCM and DAM, such as robustness and low distortion. By adjusting the scaling factor q embedded in the WLSDP, satisfactory parameterizations in different special applications can be achieved.展开更多
The continuous wavelet transform(CWT)based method was improved for estimating the natural frequencies and damping ratios of a structural system in this paper.The appropriate scale of CWT was selected by means of the l...The continuous wavelet transform(CWT)based method was improved for estimating the natural frequencies and damping ratios of a structural system in this paper.The appropriate scale of CWT was selected by means of the least squares method to identify the systems with closely spaced modes.The important issues related to estimation accuracy such as mode separation and end effect,were also investigated.These issues were associated with the parameter selection of wavelet function based on the fitting error of least squares.The efficiency of the method was confirmed by applying it to a simulated 3dof damped system with two close modes.展开更多
This paper presents empirical evidence on the financial characteristics of Chinese entrepreneurial SMEs, both state-owned and private enterprises, listed in the Chinese stock markets during 2006-2009. Building on exta...This paper presents empirical evidence on the financial characteristics of Chinese entrepreneurial SMEs, both state-owned and private enterprises, listed in the Chinese stock markets during 2006-2009. Building on extant literature and using a parametric approach on 359 sample SMEs for 2006-2009 period, the study examines the financial characteristics that are embedded in the financially healthy and unhealthy Chinese SMEs. The findings of the study suggest that financially healthy Chinese SMEs have strength in terms of liquidity, profitability, and leverage ratios as compared to financially unhealthy SMEs with the exception of a few cases in leverage and profitability. These findings are worth noting to understand the uniqueness of financial characteristics of the Chinese SMEs and useful for policy makers to deal with the issues related to financially distressed SMEs in China.展开更多
Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is...Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is obtained. The results show that the heat conductance performance of the assembly becomes ever worse with ever greater number of elemental cylindrical fins,the umbrella-shaped assembly reduces to cylindrical fin in some values of design parameters,and the diameters’ dependence on design parameters is weak for the optimized assembly. An equivalent thermal resistance defined based on entransy dissipation rate (EDR) reflects an average heat transfer effect of the assembly. The constructal design corresponding to the minimum EDR (or MTR) should be adopted for designing an assembly of fins in engineering at the limit safe condition.展开更多
文摘A new algorithm called the weighted least square discrete parameterization (WLSDP) is presented for the parameterization of triangular meshes over a convex planar region. This algorithm is the linear combination of the discrete Conformal mapping(DCM) and the discrete Authalic mapping(DAM). It provides the good properties of both DCM and DAM, such as robustness and low distortion. By adjusting the scaling factor q embedded in the WLSDP, satisfactory parameterizations in different special applications can be achieved.
文摘The continuous wavelet transform(CWT)based method was improved for estimating the natural frequencies and damping ratios of a structural system in this paper.The appropriate scale of CWT was selected by means of the least squares method to identify the systems with closely spaced modes.The important issues related to estimation accuracy such as mode separation and end effect,were also investigated.These issues were associated with the parameter selection of wavelet function based on the fitting error of least squares.The efficiency of the method was confirmed by applying it to a simulated 3dof damped system with two close modes.
文摘This paper presents empirical evidence on the financial characteristics of Chinese entrepreneurial SMEs, both state-owned and private enterprises, listed in the Chinese stock markets during 2006-2009. Building on extant literature and using a parametric approach on 359 sample SMEs for 2006-2009 period, the study examines the financial characteristics that are embedded in the financially healthy and unhealthy Chinese SMEs. The findings of the study suggest that financially healthy Chinese SMEs have strength in terms of liquidity, profitability, and leverage ratios as compared to financially unhealthy SMEs with the exception of a few cases in leverage and profitability. These findings are worth noting to understand the uniqueness of financial characteristics of the Chinese SMEs and useful for policy makers to deal with the issues related to financially distressed SMEs in China.
基金supported by the National Natural Science Foundation of China (Grant No.10905093)the Program for New Century Excellent Talents in University of China (Grant No.NCET-04-1006)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No.200136)
文摘Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is obtained. The results show that the heat conductance performance of the assembly becomes ever worse with ever greater number of elemental cylindrical fins,the umbrella-shaped assembly reduces to cylindrical fin in some values of design parameters,and the diameters’ dependence on design parameters is weak for the optimized assembly. An equivalent thermal resistance defined based on entransy dissipation rate (EDR) reflects an average heat transfer effect of the assembly. The constructal design corresponding to the minimum EDR (or MTR) should be adopted for designing an assembly of fins in engineering at the limit safe condition.
