Very Long Instruction Word （VLIW） architectures are commonly used in application-specific domains due to their parallelism and low-power characteristics. Recently, parameterization of such architectures allows for r...Very Long Instruction Word （VLIW） architectures are commonly used in application-specific domains due to their parallelism and low-power characteristics. Recently, parameterization of such architectures allows for runtime adaptation of the issue-width to match the inherent Instruction Level Parallelism （ILP） of an application. One implementation of such an approach is that the event of the issue-width switching dynamically triggers the reconfiguration of the data cache at runtime. In this paper, the relationship between cache resizing and issue-width is well investigated. We have observed that the requirement of the cache does not always correlate with the issue- width of the VLIW processor. To further coordinate the cache resizing with the changing issue-width, we present a novel feedback mechanism to ＂block＂ the low yields of cache resizing when the issue-width changes. In this manner, our feedback cache mechanism has a coordinated effort with the issue-width changes, which leads to a noticeable improvement of the cache performance. The experiments show that there is 10% energy savings as well as a 2.3% cache misses decline on average achieved, compared with the cache without the feedback mechanism. Therefore, the feedback mechanism is proven to have the capability to ensure more benefits are achieved from the dynamic and frequent reconfiguration.展开更多
The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochem...The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochemical process tower.Most of denoising methods fail to filter such noise properly.Both the signal-to-noise ratio and the peak signal-to-noise ratio are small.Multiresolution-based one-step and variational-based filtering methods fail to denoise properly with thresholds obtained by theoretical or empirical method.Duc to the fact that it is impossible to completely denoise such high-level noisy data,the enhancing approach is used to improve the data quality,which is the main novelty from the application point of view here.For this iterative method,a simple computational approach is proposed to estimate the dynamic threshold values.Hence,different thresholds can be obtained for different recorded signals in one ambient test.This is in contrast to commonly used approaches recommending one global threshold estimated mainly by an empirical method.After the enhancements,modal frequencies are directly detected by the cross wavelet transform(XWT),the spectral power density and autocorrelation of wavelet coefficients.Estimated frequencies are then compared with those of an undamaged-model,simulated by the finite element method.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61300010 and 61300011)
文摘Very Long Instruction Word （VLIW） architectures are commonly used in application-specific domains due to their parallelism and low-power characteristics. Recently, parameterization of such architectures allows for runtime adaptation of the issue-width to match the inherent Instruction Level Parallelism （ILP） of an application. One implementation of such an approach is that the event of the issue-width switching dynamically triggers the reconfiguration of the data cache at runtime. In this paper, the relationship between cache resizing and issue-width is well investigated. We have observed that the requirement of the cache does not always correlate with the issue- width of the VLIW processor. To further coordinate the cache resizing with the changing issue-width, we present a novel feedback mechanism to ＂block＂ the low yields of cache resizing when the issue-width changes. In this manner, our feedback cache mechanism has a coordinated effort with the issue-width changes, which leads to a noticeable improvement of the cache performance. The experiments show that there is 10% energy savings as well as a 2.3% cache misses decline on average achieved, compared with the cache without the feedback mechanism. Therefore, the feedback mechanism is proven to have the capability to ensure more benefits are achieved from the dynamic and frequent reconfiguration.
基金The authors gratefully acknowledge the financial support of Iran National Science Foundation(INSF).
文摘The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochemical process tower.Most of denoising methods fail to filter such noise properly.Both the signal-to-noise ratio and the peak signal-to-noise ratio are small.Multiresolution-based one-step and variational-based filtering methods fail to denoise properly with thresholds obtained by theoretical or empirical method.Duc to the fact that it is impossible to completely denoise such high-level noisy data,the enhancing approach is used to improve the data quality,which is the main novelty from the application point of view here.For this iterative method,a simple computational approach is proposed to estimate the dynamic threshold values.Hence,different thresholds can be obtained for different recorded signals in one ambient test.This is in contrast to commonly used approaches recommending one global threshold estimated mainly by an empirical method.After the enhancements,modal frequencies are directly detected by the cross wavelet transform(XWT),the spectral power density and autocorrelation of wavelet coefficients.Estimated frequencies are then compared with those of an undamaged-model,simulated by the finite element method.
