Regulating Grip Forces through EMG-Controlled Protheses for Transradial Amputees

This study aims to evaluate different combinations of features and algorithms to be used in the control of a prosthetic hand wherein both the configuration of the fingers and the gripping forces can be controlled. This requires identifying machine learning algorithms and feature sets to detect both intended force variation and hand gestures in EMG signals recorded from upper-limb amputees. However, despite the decades of research into pattern recognition techniques, each new problem requires researchers to find a suitable classification algorithm, as there is no such thing as a universal ’best’ solution. Consideration of different techniques and data representation represents a fundamental practice in order to achieve maximally effective results. To this end, we employ a publicly-available database recorded from amputees to evaluate different combinations of features and classifiers. Analysis of data from 9 different individuals shows that both for classic features and for time-dependent power spectrum descriptors (TD-PSD) the proposed logarithmically scaled version of the current window plus previous window achieves the highest classification accuracy. Using linear discriminant analysis (LDA) as a classifier and applying a majority-voting strategy to stabilize the individual window classification, we obtain 88% accuracy with classic features and 89% with TD-PSD features.

AN INTELLIGENT AIRCRAFT WINDOW SYSTEM FOR VISUAL COMFORT CONTROL

The purpose of this thesis is to develop an intelligent aircraft window system for visual comfort control based on electrochromic windows that can change the transparency depending on passenger’s needs and visual comfort. In the current window system, window transparency is controlled manually. The system developed in this thesis is an automatic system. Under this development, a mock-up is set up to mimic a section of cabin with an electrochromic window along with a simulated sunlight source and several light sensors. To measure visual comfort, the daylight glare index (DGI) is adopted. Based on DGI, a fuzzy logic classifier is developed to evaluate visual comfort/discomfort. This is followed by developing a fuzzy logic controller that can automatically adjust the window transparency based on the measured DGI level and the rate of change of DGI. DGI set point for different individuals, the effect of illuminance and color temperature are also discussed

AN INTELLIGENT AIRCRAFT WINDOW SYSTEM FOR VISUAL COMFORT CONTROL

The purpose of this thesis is to develop an intelligent aircraft window system for visual comfort control based on electrochromic windows that can change the transparency depending on passenger’s needs and visual comfort. In the current window system, window transparency is controlled manually. The system developed in this thesis is an automatic system. Under this development, a mock-up is set up to mimic a section of cabin with an electrochromic window along with a simulated sunlight source and several light sensors. To measure visual comfort, the daylight glare index (DGI) is adopted. Based on DGI, a fuzzy logic classifier is developed to evaluate visual comfort/discomfort. This is followed by developing a fuzzy logic controller that can automatically adjust the window transparency based on the measured DGI level and the rate of change of DGI. DGI set point for different individuals, the effect of illuminance and color temperature are also discussed

Method of estimation of frequency variation relying on estimation of shift of spectral peaks

Problem of estimation of variated frequency of components of polyharmonic signals has been arose. Three-dimensional time-frequency representation of signals is usually used to resolve this problem. But simple and reliable method of instantaneous frequency tracking is needed. Frequency tracking method based on estimation of shifts of peaks of spectrogram has been proposed in this paper. It is assumed that shift of spectral peaks of components of signal is proportional to variation of fundamental frequency. Logarithmic scaling of time-frequency representation is used to make spectral peaks equidistant. Temporal dependence of shift of spectral maximums is obtained using correlation of windowed spectrum at the first frame and spectrum of signal in the current window. Then obtained track is translated in linear scale. Proposed method does not estimate values of instantaneous frequency or central frequency of signal component but estimates its variation. Advantage of the method is that it can estimate frequency track even if range of frequency variation and its central value are known roughly or unknown at all. Multiple components do not interfere to estimate fundamental frequency variation. Reduction of bandwidth is recommended to increase accuracy of frequency track estimation, but analysis of time-frequency representation containing a few components is also possible. Dependency of performance of analysis of synthetic signals using the method on various signal to noise ratios under different conditions was estimated. Applicability of the method for vibrational diagnosing of rotary equipment was checked out using spectral interference method.

Ultraviolet-reflective film applied to windows reduces the likelihood of collisions for two species of songbird

Perhaps a billion birds die annually from colliding with residential and commercial windows. Therefore, there is a societal need to develop technologies that reduce window collisions by birds. Many current window films that are applied to the external surface of windows have human-visible patterns that are not esthetically preferable. BirdShades have developed a short wavelength (ultraviolet) reflective film that appears as a slight tint to the human eye but should be highly visible to many bird species that see in this spectral range. We performed flight tunnel tests of whether the BirdShades external window film reduced the likelihood that two species of song bird (zebra finch, Taeniopygia guttata and brown-headed cowbird, Molothrus ater) collide with windows during daylight. We paid particular attention to simulate the lighting conditions that birds will experience while flying during the day. Our results indicate a 75–90% reduction in the likelihood of collision with BirdShades-treated compared with control windows, in forced choice trials. In more ecologically relevant comparison between trials where all windows were either treated or control windows, the estimated reduction in probability of collision was 30–50%. Further, both bird species slow their flight by approximately 25% when approaching windows treated with the BirdShades film, thereby reducing the force of collisions if they were to happen. Therefore, we conclude that the BirdShades external window film will be effective in reducing the risk of and damage caused to populations and property by birds’ collision with windows. As this ultraviolet-reflective film has no human-visible patterning to it, the product might be an esthetically more acceptable low cost solution to reducing bird-window collisions. Further, we call for testing of other mitigation technologies in lighting and ecological conditions that are more similar to what birds experience in real human-built environments and make suggestions for testing standards to assess collision-reducing technologies.

Sharing Economy: Promote Its Potential to Sustainability by Regulation

The sharing economy is an emerging economic form with the potential to promote sustainable development; it is highly malleable but tends to not be environmentally friendly or necessarily lead to saving resources. Therefore, to give it the inherent logic of sustainable development and realize its great potential, the sharing economy must be made to meet the necessary conditions and be appropriately regulated in the current window of opportunity. This paper proposes that the potential factors of the sharing economy that can promote sustainable development are mainly improving resource utilization efficiency, market impetus and plasticity and transforming consumption patterns and concepts, while the main limiting factors are the excessive demand that is likely to result from to the descending consumption threshold, lack of maintenance motivation due to the sharing of property rights, and uncertainty in the proportions of increased welfare levels and resource consumption. Then, the paper explores the necessary conditions to promote sustainable development in the sharing economy, namely, the required characteristics of shared products and the need to place constraints on consumers. Next, it discusses how to incorporate these conditional factors into the regulatory framework for the future development of the sharing economy and proposes overall principles and ideas for the governance and regulation of producers, consumers, and platform operators in the operation of and participation in the sharing economy. Finally, the paper emphasizes that the line of regulatory thinking should change because the sharing economy differs from traditional economic forms, and it also emphasizes the importance of exploring conditions and explores the related research prospects for studying regulation with environmental sustainability as the regulatory objective.

Vector Radix 2 × 2 Sliding Fast Fourier Transform

The two-dimensional (2D) discrete Fourier transform (DFT) in the sliding window scenario has been successfully used for numerous applications requiring consecutive spectrum analysis of input signals. However, the results of conventional sliding DFT algorithms are potentially unstable because of the accumulated numerical errors caused by recursive strategy. In this letter, a stable 2D sliding fast Fourier transform (FFT) algorithm based on the vector radix (VR) 2 × 2 FFT is presented. In the VR-2 × 2 FFT algorithm, each 2D DFT bin is hierarchically decomposed into four sub-DFT bins until the size of the sub-DFT bins is reduced to 2 × 2; the output DFT bins are calculated using the linear combination of the sub-DFT bins. Because the sub-DFT bins for the overlapped input signals between the previous and current window are the same, the proposed algorithm reduces the computational complexity of the VR-2 × 2 FFT algorithm by reusing previously calculated sub-DFT bins in the sliding window scenario. Moreover, because the resultant DFT bins are identical to those of the VR-2 × 2 FFT algorithm, numerical errors do not arise; therefore, unconditional stability is guaranteed. Theoretical analysis shows that the proposed algorithm has the lowest computational requirements among the existing stable sliding DFT algorithms.