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In recent years, there has been a considerable amount of research on visual evoked potential (VEP)-based brain–computer interfaces (BCIs). However, it remains a big challenge to detect VEPs elicited by small visual stimuli. To address this challenge, this study employed a 256-electrode high-density electroencephalogram (EEG) cap with 66 electrodes in the parietal and occipital lobes to record EEG signals. An online BCI system based on code-modulated VEP (C-VEP) was designed and implemented with thirty targets modulated by a time-shifted binary pseudo-random sequence. A task-discriminant component analysis (TDCA) algorithm was employed for feature extraction and classification. The offline and online experiments were designed to assess EEG responses and classification performance for comparison across four different stimulus sizes at visual angles of 0.5°, 1°, 2°, and 3°. By optimizing the data length for each subject in the online experiment, information transfer rates (ITRs) of 126.48 ± 14.14 bits/min, 221.73 ± 15.69 bits/min, 258.39 ± 9.28 bits/min, and 266.40 ± 6.52 bits/min were achieved for 0.5°, 1°, 2°, and 3°, respectively. This study further compared the EEG features and classification performance of the 66-electrode layout from the 256-electrode EEG cap, the 32-electrode layout from the 128-electrode EEG cap, and the 21-electrode layout from the 64-electrode EEG cap, elucidating the pivotal importance of a higher electrode density in enhancing the performance of C-VEP BCI systems using small stimuli. [ABSTRACT FROM AUTHOR]

The construction of high-performance n-type semiconductors is crucial for the advancement of organic electronics. As an attractive n-type semiconductor, molecular systems based on perylene diimide derivatives (PDIs) have been extensively investigated over recent years. Owing to the fascinating aggregated structure and high performance, S-heterocyclic annulated PDIs (SPDIs) are receiving increasing attention. However, the relationship between the structure and the electrical properties of SPDIs has not been deeply revealed, restricting the progress of PDI-based organic electronics. Here, we developed two novel SPDIs with linear and dendronized substituents in the imide position, named linear SPDI and dendronized SPDI, respectively. A series of structural and property characterizations indicated that linear SPDI formed a long-range-ordered crystalline structure based on helical supramolecular columns, while dendronized SPDI, with longer alkyl side chains, formed a 3D-ordered crystalline structure at a low temperature, which transformed into a hexagonal columnar liquid crystal structure at a high temperature. Moreover, no significant charge carrier transport signal was examined for linear SPDI, while dendronized SPDI had a charge carrier mobility of 3.5 × 10−3 cm2 V−1 s−1 and 2.1 × 10−3 cm2 V−1 s−1 in the crystalline and liquid crystalline state, respectively. These findings highlight the importance of the structure–function relationship in PDIs, and also offer useful roadmaps for the design of high-performance organic electronics for down-to-earth applications. [ABSTRACT FROM AUTHOR]

Compared with traditional methods, the action recognition model based on 3D convolutional deep neural network captures spatio-temporal features more accurately, resulting in higher accuracy. However, the large number of parameters and computational requirements of 3D models make it difficult to deploy on mobile devices with limited computing power. In order to achieve an efficient video action recognition model, we have analyzed and compared classic lightweight network principles and proposed the 3D-ShuffleViT network. By deeply integrating the self-attention mechanism with convolution, we have introduced an efficient ACISA module that further enhances the performance of our proposed model. This has resulted in exceptional performance in both context-sensitive and context-independent action recognition, while reducing deployment costs. It is worth noting that our 3D-ShuffleViT network, with a computational cost of only 6% of that of SlowFast-ResNet101, achieved 98% of the latter's Top1 accuracy on the EgoGesture dataset. Furthermore, on the same CPU (Intel i5-8300H), its speed was 2.5 times that of the latter. In addition, when we deployed our model on edge devices, our proposed network achieved the best balance between accuracy and speed among lightweight networks of the same order. [ABSTRACT FROM AUTHOR]

The rapid development of new first-tier cities in China has led to potentially significant differences in residents' environmental perceptions toward parks in new and old urban areas. However, there is currently a lack of relevant comparative research. Therefore, this study used the new first-tier city of Hefei as an example and selected the two most popular urban parks in the new and old downtown areas—Swan Lake Park and Xiaoyaojin Park. This study aimed to find out which aspects of the new and old city parks were the most valued by the residents by analysing their online comments on social media platforms. Based on the social media comments, quantitative and qualitative analyses were conducted to study residents' perceptions and preferences and analyse residents' activities and satisfaction. The research found the following: (1) There was consistency in the type of content in the downtown parks as perceived by the residents of the new and old urban areas. (2) For the old downtown Xiaoyaojin Park, the residents were more interested in the experience in terms of the recreation facilities and services but were less satisfied with the visitor capacity of the playground and the ticket price. For the new downtown Swan Lake Park, the residents were more interested in the experience in terms of the exercise facilities and venues and were worried about the safety of the venues. (3) The perceived environmental preferences of the residents in the old urban areas were mainly related to childhood activity venues, and the perceived environmental preferences of the residents in the new urban areas were mainly related to novelty activities. Based on the results, targeted suggestions were proposed for the development of characteristic resources, facility management and maintenance, and the renewal and renovation of recreational activities. Since social media analysis plays an important role in the construction of urban parks, the findings can help us to better understand residents' lives, ensure that parks are designed for the happiness of the people, and develop more sustainable pathways for the design and management of urban areas. [ABSTRACT FROM AUTHOR]

The thermal comfort of outdoor spaces in traditional villages must be improved because high building density combined with complex and narrow spaces leads to a poor thermal environment. In traditional villages, outdoor spaces are the most frequently used places by local residents and tourists. In this study, the Shimengao Village in Tangxi Town, Chizhou City, a typical mountainous area in the southern Anhui Province, was selected as the research object, and Depthmap software was used to identify the most frequently used outdoor spaces. The spatial layout and three different outdoor spaces of the traditional village were measured and validated using ENVI-met software. In addition, the distribution of thermal comfort in the core area of the village and influencing factors were analyzed. Our results demonstrated that during summer, PET reached its highest value at 15:00, exhibiting a poor thermal environment in the core area of traditional village integration. From 15:00 to 21:00, PET values declined, resulting in improved thermal comfort levels. Open spaces had better thermal comfort ratings throughout the day. The thermal comfort distribution of three different types of outdoor space in traditional villages was also analyzed. The courtyard space had the worst thermal comfort, followed by the street space, whereas the square space had the best thermal comfort environment. This was correlated with the spatial layout of traditional villages, external facilities of buildings, microlandscapes (plants, water availability, etc.), and outdoor ground materials. Hence, we propose that optimizing the overall spatial layout of a traditional village, increasing the external facilities of buildings, creating "micro landscapes," and optimizing the materials of outdoor spaces are important for improving the thermal comfort of the outdoor spaces of traditional villages. [ABSTRACT FROM AUTHOR]

In this paper, an incremental nonlinear dynamic inversion (INDI) control scheme is proposed for the attitude tracking of a helicopter with model uncertainties, and actuator delay and saturation constraints. A finite integral compensation based on model reduction is used to compensate the actuator delay, and the proposed scheme can guarantee the semi-globally uniformly ultimately bounded tracking. The overall attitude controller is separated into a rate, an attitude, and a collective pitch controller. The rate and collective pitch controllers combine the proposed method and INDI to enhance the robustness to actuator delay and model uncertainties. Considering the dynamic of physical actuators, pseudo-control hedging (PCH) is introduced both in the rate and attitude controller to improve tracking performance. By using the proposed controller, the helicopter shows good dynamics under the multiple restrictions of the actuators. [ABSTRACT FROM AUTHOR]

Despite the implementation of hydraulic fracturing technologies, the oil recovery in tight oil reservoirs is still poor. In this study, cationic, anionic, and nonionic surfactants of various sorts were investigated to improve oil recovery in tight carbonate cores from the Middle Bakken Formation in the Williston Basin. Petrophysical investigations were performed on the samples prior to the imbibition and core-flooding experiments. The composition of the minerals was examined using the XRD technique. To investigate the pore-size distribution and microstructures, nitrogen adsorption and SEM techniques were applied. The next step involved brine and surfactant imbibition for six Bakken cores and two Berea sandstone cores. The core samples were completely saturated with Bakken crude oil prior to the experiments. The core plugs were then submerged into the brine and surfactant solutions. The volume of recovered oil was measured using imbibition cells as part of experiments involving brine and surfactant ingestion into oil-filled cores. According to the findings, oil recovery from brine imbibition ranges from 4.3% to 15%, whereas oil recovery from surfactant imbibition can range from 9% to 28%. According to the findings, core samples with more clay and larger pore diameters produce higher levels of oil recovery. Additionally, two tight Bakken core samples were used in core-flooding tests. Brine and a separate surfactant solution were the injected fluids. The primary oil recovery from brine flooding on core samples is between 23% and 25%, according to the results. The maximum oil recovery by second-stage surfactant flooding is approximately 33% and 35%. The anionic surfactants appear to yield a better oil recovery in tight Bakken rocks, possibly due to their higher carbonate mineral concentrations, especially clays, according to both the core-scale imbibition and flooding experiments. For studied samples with larger pore sizes, the oil recovery is higher. The knowledge of the impacts of mineral composition, pore size, and surfactant types on oil recovery in tight carbonate rocks is improved by this study. [ABSTRACT FROM AUTHOR]

As a main place for student activities on campus, outdoor spaces have positive impacts on students' physical and mental health. Namely, outdoor heat and comfort are of great significance to improve activity quality. Here, four unique outdoor spaces were studied to explore the varying effects on human thermal comfort during hot-summer and cold-winter periods. Distinct outdoor spaces (fully open, semi-open, semi-enclosed, and fully enclosed areas) from the southern campus of Anhui Jianzhu University were chosen. The PET was used as a metric for measuring thermal comfort and analyzing correlated spatiotemporal distributions. The results showed that outdoor thermal comfort was derived from multiple factors, including vegetation, underlying surface materials, building presence, and wind-heat environment. Notably, high correlations between Tmrt and thermal comfort were revealed, where such temperatures of places with trees or building shade were low; thus, PET was low. Further, Ws showed a significantly negative correlation with PET. Of the four outdoor space forms, the fully enclosed location had the lowest thermal comfort level, while the semi-enclosed spaces showed the highest level of body comfort. Therefore, semi-enclosed space (U-shaped) is recommended in campus planning and construction. Accordingly, an improved strategy was proposed based on experimental transformation for fully enclosed spaces. The thermal comfort after optimization was simulated to provide references for outdoor space thermal comfort improvement during seasonal extremes. [ABSTRACT FROM AUTHOR]

In comparison with European and American countries, the CSR of professional sports in Asian countries is affected by many factors due to differences in management system, social environment, etc. At present, the research on CSR of professional sports in Asian countries is very limited, and the practice form of CSR under this special management system has great research space and value. For booming professional sports of China, neighboring Japanese professional sports system is similar to it, and has a more advanced level of professional sports CSR development, which is worthy of further learning and reference for Chinese Super League clubs. Therefore, this study combs the historical background, core content and governance experience of CSR of J League in Japan, and puts forward valuable enlightenment for Chinese Super League clubs. The results show that the CSR of J League in Japan has distinctive characteristics and times, and the Chinese Super League clubs need to combine their own development stages, Chinese national conditions and other factors for reference. [ABSTRACT FROM AUTHOR]

We developed an optimized system for solving engineering problems according to the characteristics of data. Because data analysis includes different variations, the use of common features can increase the performance and accuracy of models. Therefore, this study, using a combination of optimization techniques (K-means algorithm) and prediction techniques, offers a new system and procedure that can identify and analyze data with similarity and close grouping. The system developed using the new sparrow search algorithm (SSA) has been updated as a new hybrid solution to optimize development engineering problems. The data for proposing the mentioned techniques were collected from a series of laboratory works on samples of steel fiber-reinforced concrete (SFRC). To investigate the issue, the data were first divided into different clusters, taking into account common features. After introducing the top clusters, each cluster was developed using three predictive models, i.e., multi-layer perceptron (MLP), support vector regression (SVR), and tree-based techniques. This process continues until the criteria are met. Accordingly, the K-means–artificial neural network 3 structure shows the best performance in terms of accuracy and error. The results also showed that the structure of hybrid models with cluster numbers 2, 3, and 4 is higher than the baseline models in terms of accuracy for assessing the punching shear capacity (PSC) of SFRC. The K-means–ANN3-SSA generated a new methodology for optimizing PSC. The new proposed model/procedure can be used for a similar situation by combining clustering and prediction methods. [ABSTRACT FROM AUTHOR]

Graphene-silica (RGO-SiO2) was successfully synthesized by a simple hydrothermal method. The composites were used to study the adsorption properties of humic acid and disinfection by-product precursors in natural surface water. Compared with reduced graphene oxide (RGO), the specific surface area of the composites doped with silica (SiO2) increased by 31.2% to 259.43 m2/g. RGO-SiO2 could achieve 66.91% adsorption of humic acid (HA), while the maximum adsorption of HA on RGO-SiO2 reached 925.91 mg/g. The adsorption and removal rates of HA by RGO-SiO2 were significantly higher than those of RGO. The whole adsorption process was in accordance with the quasi-secondary kinetic model, the Langmuir isothermal adsorption model. RGO-SiO2 has good adsorption performance for organic matter of different water qualities. RGO-SiO2 has a better removal ability for hydrophobic organics than hydrophilic and nitrogenous organics. The adsorbent was reusable, and the organic removal efficiency of RGO-SiO2 decreased insignificantly after four cycles. [ABSTRACT FROM AUTHOR]

Purpose: Using micro-CT and finite element analysis to establish regional variation microarchitectures and correlation with mechanical properties of cervical articular facet trabecular bone to predict cervical spine security and material properties. Methods: A total of 144 cervical articular processes (each articular was separate to four region of interest (ROI), superior-anterior (SA), superior-posterior (SP), inferior-anterior (IA), and inferior-posterior (IP) regions) specimens with a volume of 5 × 5 × 5 mm3 were scanned by micro-CT, and allowable stress and other mechanical properties parameters in each region were calculated after mechanical testing, then the effectiveness was verified of finite element models by ABAQUS software. Results: Maximum and minimum values of C2–C7 articular processes and regions are C5 and C7 level, SA and SP regions for bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), whose variation tendency is similar to the Young's modulus, allowable stress, BMD, maximum force and strain. Between Young's modulus and all microstructure parameters, especially between BV/TV, bone mineral density (BMD) and Tb.Th, had higher linear regression coefficients R2 = 0.5676, 0.6382, 0.3535, respectively. BMD and yield strength, BV/TV, and allowable stress also had better regression coefficients, R2 = 0.5227, 0.5259, 0.5426, respectively. Conclusions: The contribution of the microstructure and mechanical properties of the C2–C7 cervical spine to the movement of the cervical spine is different and has a good correlation and the effectiveness of the finite element model is also verified that we can correctly calculate the microstructure and mechanical properties of the cervical articular process to evaluate the stability and injury risk of cervical vertebrae by the established model. [ABSTRACT FROM AUTHOR]

The radial-flow turbine, a key component of the supercritical CO2 (S-CO2) Brayton cycle, has a significant impact on the cycle efficiency. The inlet volute is an important flow component that introduces working fluid into the centripetal turbine. In-depth research on it will help improve the performance of the turbine and the entire cycle. This article aims to improve the volute flow capacity by optimizing the cross-sectional geometry of the volute, thereby improving the volute performance, both at design and non-design points. The Gaussian process surrogate model based parameter sensitivity analysis is first conducted, and then the optimization process is implemented by Bayesian optimization (BO) wherein the acquisition function is used to query optimal design. The results show that the optimized volute has better and more uniform flow characteristics at design and non-design points. It has a smoother off-design conditions performance curve. The total pressure loss coefficient at the design point of the optimized volute is reduced by 33.26%, and the flow deformation is reduced by 54.55%. [ABSTRACT FROM AUTHOR]