31 research outputs found
Carrying forward Uses and Grat 2.0: A study of new gratifications for F2P games based on APEX Legends
This study employed a Uses and Gratifications (U&G) theoretical framework (MAIN model) to investigate the effects of virtual items in free-to-play (F2P) games on players\u27 satisfaction. Additionally, this study tried to investigate extra satisfaction that players get in the process of consuming virtual items. A mixed-method survey in China with a sample size of 265 participants was utilized to test the research questions. The findings of the study revealed significant variations in satisfaction related to personalization and sociality level between free players and paying players, and the degree was positively correlated with the in-game spending level. In addition, one satisfaction not included in prior research on video games—superiority—was found through qualitative data analysis. Keywords: Virtual items, free-to-play, purchase, Uses and gratifications (U&G
Trends of satellite derived chlorophyll-a (1997–2011) in the Bohai and Yellow Seas, China: Effects of bathymetry on seasonal and inter-annual patterns
Effects of Technological Innovation Network Embeddedness on the Sustainable Development Capability of New Energy Enterprises
The rapid development of China’s economy has led to increasing problems with energy security and environmental pollution. Sustainable economic and environmental development in China can be effectively ensured through the sustainable development of new energy enterprises. Moreover, network theory holds that enterprises form multiple complex and diverse social networks through their interconnection, which further boosts the sustainable development of enterprises. This study used the social network analysis method and the accelerating genetic algorithm projection pursuit model, embedded new energy enterprises in technological innovation networks, and established a conceptual model that included network embeddedness, external resource acquisition, corporate social responsibility, and the sustainable development capability of enterprises. Then, hierarchical regression analysis was used to test the conceptual model. The results of this study provide a new theoretical basis and relevant policy suggestions for the sustainable development of China’s new energy enterprises. The results are also important for China’s environmental governance and for creating a green and harmonious future ecological environment
Low-SNR Infrared Point Target Detection and Tracking via Saliency-Guided Double-Stage Particle Filter
Low signal-to-noise ratio (SNR) infrared point target detection and tracking is crucial to study regarding infrared remote sensing. In the low-SNR images, the intensive noise will submerge targets. In this letter, a saliency-guided double-stage particle filter (SGDS-PF) formed by the searching particle filter (PF) and tracking PF is proposed to detect and track targets. Before the searching PF, to suppress noise and enhance targets, the single-frame and multi-frame target accumulation methods are introduced. Besides, the likelihood estimation filter and image block segmentation are proposed to extract the likelihood saliency and obtain proper proposal density. Guided by this proposal density, the searching PF detects potential targets efficiently. Then, with the result of the searching PF, the tracking PF is adopted to track and confirm the potential targets. Finally, the path of the real targets will be output. Compared with the existing methods, the SGDS-PF optimizes the proposal density for low-SNR images. Using a few accurate particles, the searching PF detects potential targets quickly and accurately. In addition, initialized by the searching PF, the tracking PF can keep tracking targets using very few particles even under intensive noise. Furthermore, the parameters have been selected appropriately through experiments. Extensive experimental results show that the SGDS-PF has an outstanding performance in tracking precision, tracking reliability, and time consumption. The SGDS-PF outperforms the other advanced methods
Implementation of Real-Time Space Target Detection and Tracking Algorithm for Space-Based Surveillance
Space-based target surveillance is important for aerospace safety. However, with the increasing complexity of the space environment, the stellar target and strong noise interference pose difficulties for space target detection. Simultaneously, it is hard to balance real-time processing with computational performance for the onboard processing platform owing to resource limitations. The heterogeneous multi-core architecture has corresponding processing capabilities, providing a hardware implementation platform with real-time and computational performance for space-based applications. This paper first developed a multi-stage joint detection and tracking model (MJDTM) for space targets in optical image sequences. This model combined an improved local contrast method and the Kalman filter to detect and track the potential targets and use differences in movement status to suppress the stellar targets. Then, a heterogeneous multi-core processing system based on a field-programmable gate array (FPGA) and digital signal processor (DSP) was established as the space-based image processing system. Finally, MJDTM was optimized and implemented on the above image processing system. The experiments conducted with simulated and actual image sequences examine the accuracy and efficiency of the MJDTM, which has a 95% detection probability while the false alarm rate is 10−4. According to the experimental results, the algorithm hardware implementation can detect targets in an image with 1024 × 1024 pixels in just 22.064 ms, which satisfies the real-time requirements of space-based surveillance
A Space Target Detection Method Based on Spatial–Temporal Local Registration in Complicated Backgrounds
Human space exploration has brought a growing crowded operating environment for in-orbit spacecraft. Monitoring the space environment and detecting space targets with photoelectric equipment has extensive and realistic significance in space safety. In this study, a local spatial–temporal registration (LSTR) method is proposed to detect moving small targets in space. Firstly, we applied the local region registration to estimate the neighbor background motion model. Secondly, we analyzed the temporal local grayscale difference between the strong clutter and target region and measured the temporal local–central region difference to enhance the target. Then, the temporal pixel contrast map was calculated, which further retains the target signal and suppresses the residue clutter. Finally, a simple adaptive threshold segmentation algorithm was applied to the saliency map to segment the targets. Comparative experiments were conducted on four groups of image sequences to validate the efficiency and robustness of the algorithm. The experimental findings indicate that the proposed method performs well in target enhancement and clutter suppression under different scenarios
Pore structure and splitting tensile strength of hybrid Basalt–Polypropylene fiber reinforced concrete subjected to carbonation
10.1016/j.conbuildmat.2021.123779Construction and Building Materials297123779-123779complete
Thermal-sensitive hydrogel as adjuvant-free vaccine delivery system for H5N1 intranasal immunization
For H5N1 influenza immunization, we developed a thermal-sensitive hydrogel as intranasal vaccine delivery system, which was formulated with N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC) and alpha, beta-glycerophosphate (alpha, beta-GP). The flowing solution of HTCC/CP under room temperature could gelate rapidly at body temperature, which significantly prolonged the H5N1 split antigen residence time in nasal cavity. This system also enhanced the transepithelial transport via the paracellular routes due to the disorganization of ZO-1 protein in nasal epithelial tissue. In comparison to naked H5N1 split antigen and MF59 adjuvanted antigen, as designed hydrogel/H5N1 vaccine induced greater antigen-specific systemic immune responses and mucosal IgA immunity without adjuvants. Furthermore, a boosted cellular and humoral response was also obtained by examination of IFN-gamma and IL-4 cytokines, respectively. In addition, hydrogel based formulation promoted the antigen-specific CD8(+) T cell immune memory as determined by the proportion of central and effector memory CD8(+) T cells in nasal associated lymphoid tissue (NALT). These results demonstrate that the HTCC hydrogel has potential as an adjuvant-free platform for H5N1 split antigen intranasal vaccination. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved