A wide range of camera apps and online video conferencing services support the feature of changing the background in real-time for aesthetic, privacy, and security reasons. Numerous studies show that the Deep-Learning (DL) is a suitable option for human segmentation, and the ensemble of multiple DL-based segmentation models can improve the segmentation result. However, these approaches are not as effective when directly applied to the image segmentation in a video. This paper proposes an Adaptive N-Frames Ensemble (AFE) approach for high-movement human segmentation in a video using an ensemble of multiple DL models. In contrast to an ensemble, which executes multiple DL models simultaneously for every single video frame, the proposed AFE approach executes only a single DL model upon a current video frame. It combines the segmentation outputs of previous frames for the final segmentation output when the frame difference is less than a particular threshold. Our method employs the idea of the N-Frames Ensemble (NFE) method, which uses the ensemble of the image segmentation of a current video frame and previous video frames. However, NFE is not suitable for the segmentation of fast-moving objects in a video nor a video with low frame rates. The proposed AFE approach addresses the limitations of the NFE method. Our experiment uses three human segmentation models, namely Fully Convolutional Network (FCN), DeepLabv3, and Mediapipe. We evaluated our approach using 1711 videos of the TikTok50f dataset with a single-person view. The TikTok50f dataset is a reconstructed version of the publicly available TikTok dataset by cropping, resizing and dividing it into videos having 50 frames each. This paper compares the proposed AFE with single models and the Two-Models Ensemble, as well as the NFE models. The experiment results show that the proposed AFE is suitable for low-movement as well as high-movement human segmentation in a video. 相似文献
A brain–computer interface (BCI) provides a link between the human brain and a computer. The task of discriminating four classes (left and right hands and feet) of motor imagery movements of a simple limb-based BCI is still challenging because most imaginary movements in the motor cortex have close spatial representations. We aimed to classify binary limb movements, rather than the direction of movement within one limb. We also investigated joint time-frequency methods to improve classification accuracies. Neither of these, to our knowledge, has been investigated previously in BCI. We recorded EEG data from eleven participants, and demonstrated the classification of four classes of simple-limb motor imagery with an accuracy of 91.46% using intrinsic time-scale decomposition and 88.99% using empirical mode decomposition. In binary classifications, we achieved average accuracies of 89.90% when classifying imaginary movements of left hand versus right hand, 93.1% for left hand versus right foot, 94.00% for left hand versus left foot, 83.82% for left foot versus right foot, 97.62% for right hand versus left foot, and 95.11% for right hand versus right foot. The results show that the binary classification performance is slightly better than that of four-class classification. Our results also show that there is no significant difference in terms of spatial distribution between left and right foot motor imagery movements. There is also no difference in classification performances involving left or right foot movement. This work demonstrates that binary and four-class movements of the left and right feet and hands can be classified using recorded EEG signals of the motor cortex, and an intrinsic time-scale decomposition (ITD) feature extraction method can be used for real time brain computer interface.
The study investigated crossover of stress and strain in the workplace on a sample of 47 school principals and 183 teachers in Israeli elementary schools. The main goal of this study was to examine whether the crossover effect found among couples in the family also exists in the workplace. A 2nd aim of the study as to unravel the mechanisms that account for the crossover process. Using structural equation modeling, the authors found a significant crossover of job-induced tension but not of burnout from principals to teachers and vice versa. Being undermined by their principals elevated teachers' burnout and job-induced tension. This is the 1st study to demonstrate crossover of strain in the workplace and to discuss the implications of contagious job-induced tension in work environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
In an age of managed care, how does the clinician best help couples in marital distress? Do the short-term protocols developed and tested in the laboratory really work in the average clinical setting? This project examined the feasibility and effectiveness of implementing a laboratory-based program designed to prevent the development of relationship distress within an HMO. Both men and women reported high satisfaction with the program and a subjective sense that it was helpful for their relationships. Specific suggestions are made for assisting therapists in using effective treatments for couples in managed-care settings (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
The behaviour of reactive dyes of high reactivity during the printing process of 100% cotton fabrics from an alkaline and acidic printing paste was studied in detail. The printing pastes were stored for different periods of time and then the fabrics were printed. The samples were subjected to two methods of fixation, the first by steaming and the second by thermofixation. The effects of different factors such as alkali and acid concentration, storage time of the printing pastes and method of fixation on the K/S values of the prints were investigated. The fastness properties of the printed areas were also measured to determine the improvement obtained by acidic printing with high-reactivity reactive dyes on cotton fabrics. 相似文献
Factorial design approach was undertaken to determine the effect of initial moist-curing duration (0 and 6 days) on properties of high-performance concrete (HPC) made with different water-to-cementitious materials ratios (w/cm) of 0.30 and 0.40 and sand substitution rates with lightweight sand (LWS) of 0 and 30 %, by volume. Mechanical properties of HPC are shown to be mainly affected by w/cm and total shrinkage of concrete by the LWS replacement rate and initial moist-curing period. It should be noted that concrete made with 30 % LWS replacement that did not receive any moist-curing exhibited lower shrinkage than moist-cured concrete prepared without any LWS, regardless of the w/cm. Combined use of 30 % LWS and 7 days of moist curing can lead to greater increase in compressive strength and larger decrease in total shrinkage compared to the use of 30 % LWS without moist curing or 7 days of moist curing without LWS. The use of LWS, however, is more practical and efficient to reduce shrinkage of HPC for deep concrete elements. 相似文献
Gastric cancer (GC) represents the fifth most frequently diagnosed cancer worldwide, with a poor prognosis in patients with advanced disease despite many improvements in systemic treatments in the last decade. In fact, GC has shown resistance to several treatment options, and thus, notable efforts have been focused on the research and identification of novel therapeutic targets in this setting. The tumor microenvironment (TME) has emerged as a potential therapeutic target in several malignancies including GC, due to its pivotal role in cancer progression and drug resistance. Therefore, several agents and therapeutic strategies targeting the TME are currently under assessment in both preclinical and clinical studies. The present study provides an overview of available evidence of the inflammatory TME in GC, highlighting different types of tumor-associated cells and implications for future therapeutic strategies. 相似文献
This paper presents a reliability-based approach for the analysis and design of a shallow strip footing subjected to a vertical load with or without pseudostatic seismic loading. Only the punching failure mode of the ultimate limit state is studied. The deterministic models are based on the upper-bound method of the limit analysis theory. The random variables used are the soil shear strength parameters and the horizontal seismic coefficient. The Hasofer-Lind reliability index and the failure probability are determined. A sensitivity analysis is also performed. The influence of the applied footing load on the reliability index and the corresponding design point is presented and discussed. It was shown that the negative correlation between the soil shear strength parameters highly increases the reliability of the foundation and that the failure probability is highly influenced by the coefficient of variation of the angle of internal friction of the soil and the horizontal seismic coefficient. For design, an iterative procedure is performed to determine the breadth of the footing for a target failure probability. 相似文献
The concept of sustainable energy development cannot be separated from the understanding of additional positive socio-economic effect of sustainable energy projects (energy efficiency measures, use of renewable energy sources). Implementation of sustainable energy projects has positive impact on security of energy supply, provides financial economies and improved comfort and has multiplier effect for new jobs, involving small and medium size enterprises. Therefore integration of sustainable energy projects into regional development process may create external positive effect concerning increased energy security and other regional development goals (reduction of unemployment, reduction of environmental impact, etc.). The examples of EU-15 countries implementing their sustainable energy development and climate change mitigation policies on local level can be successfully applied in Lithuania. The aim of the article is to discuss methodological problems related with integration of sustainable energy projects into regional development procedures and provide guidelines, ensuring that energy elements may compile integral uniformity in terms of regional goals. 相似文献