Abstract: An inter-blade vibration damper for a gas turbine engine has an elongate damper body. The damper body is formed as a truncated cone and has a longitudinal axis. The elongate damper body is formed as a truncated cone. A conic surface of the damper body contacts a portion of a first blade and a portion of an adjoining second blade.

Abstract: Methods of vibration testing a component are provided. In a model of the component, define alignment points corresponding to physical features and define measurement points at positions which vibrate when excited at predefined excitation frequencies (fe), the excitation frequencies (fe) each corresponding to one or more vibrational modes. On the component measure the position of the physical features corresponding to the alignment points in the model and calculate the position of the laser source. Excite the component at an excitation frequency and measure the amplitude of vibration at each measurement point. Extract the mode shape from the measured vibration amplitudes. In the model, rotate a local co-ordinate system (x, y, z) at each measurement point until one axis is directed towards the laser source. Extract the mode shape from the component model. Compare the mode shapes extracted from the model and from measured vibration amplitudes.

Abstract: Methods of vibration testing a component are provided. In a model of the component, define alignment points corresponding to physical features and define measurement points at positions which vibrate when excited at predefined excitation frequencies (fe), the excitation frequencies (fe) each corresponding to one or more vibrational modes. On the component measure the position of the physical features corresponding to the alignment points in the model and calculate the position of the laser source. Excite the component at an excitation frequency and measure the amplitude of vibration at each measurement point. Extract the mode shape from the measured vibration amplitudes. In the model, rotate a local co-ordinate system (x, y, z) at each measurement point until one axis is directed towards the laser source. Extract the mode shape from the component model. Compare the mode shapes extracted from the model and from measured vibration amplitudes.

Abstract: A tone dependent green-noise error diffusion method includes setting a first threshold and a second threshold, and determining a two-level value of a color level of an input image according to the first threshold and the second threshold; subtracting the two-level value from the color level value to generate an error value; performing an error diffusion on the error value to generate an error diffusion accumulation value; adjusting the color level according to the error diffusion accumulation value; performing a hysteresis filtering on the two-level value to generate an output dependent feedback value; and adjusting the color level according to the output dependent feedback value.

Abstract: A tone dependent green-noise error diffusion method includes setting a first threshold and a second threshold, and determining a two-level value of a color level of an input image according to the first threshold and the second threshold; subtracting the two-level value from the color level value to generate an error value; performing an error diffusion on the error value to generate an error diffusion accumulation value; adjusting the color level according to the error diffusion accumulation value; performing a hysteresis filtering on the two-level value to generate an output dependent feedback value; and adjusting the color level according to the output dependent feedback value.