Unmanned aerial vehicles (UAVs) path planning refers to exploring the optimal flight trajectory from the starting point to the destination that satisfies the UAV under specific constraints such as ...maneuverability and environmental information constraints, which is a crucial technology for the UAV mission planning. In order to enhance the efficiency and safety of the UAV path planning task, a new autonomous UAV path planning system based on deep reinforcement learning is proposed in this article. At the beginning, a new action guidance strategy based on the Deep Q-Network (DQN) algorithm is introduced via deploying the Gravity-aware Deep Q-Network (Ga-DQN) method. This strategy can effectively assist the UAVs to avoid the obstacles in the specific state. For balancing the efficiency and safety of the task, a reward scheme that introduces a safety counting mechanism is proposed to provide global guidance for the agent in Deep Reinforcement Learning (DRL). The simulation results under different obstacle densities show that the proposed novel strategy can obviously behave robust and greater efficiency compared to the traditional methods.
An Unmanned Aerial Vehicles (UAVs) related research hotspot appertains to the autonomy, and as a filed extension, the autonomous path planning is also of concern. In allusion to the demands of path ...planning in dynamic environments, a hybrid double-deck joint path planning strategy based on deep Q-network and Q-learning (D3Q) is proposed in this paper. In comparison to the single deep Q-network (DQN) for path planning in dynamic environments, the proposed D3Q utilizes two algorithms to handle static and dynamic obstacles, respectively, which refrains from the problem of poor network fitting when only employing DQN. Furthermore, a heuristic fish (HF) algorithm is presented as a prior strategy to assist D3Q in exploring the environments so as to speed up the training. Simulation results demonstrate that our advocated approach has an excellent performance in performing dynamic path planning in different scenarios and can generate relatively shorter and more dependable trajectories.
Herein, we propose a novel Ti3C2 grafted SiO2 (Ti3C2-g-SiO2, 21.2% loading weight content of SiO2) multifunctional filler with an average thickness of 10 ± 2 nm, which is skillfully prepared via an ...in-situ growing approach, to blend with styrene-butadiene rubber (SBR) and create high-performance elastomer composites. Thanks to the incorporation of SiO2, the Ti3C2-g-SiO2 not only disperses better (a uniform state) than Ti3C2 in the rubber matrix but also obtains innumerous nano protuberances on its surface to constrain more rubber chains than Ti3C2, significantly improving the interfacial interaction. Therefore, by comparison of the unfilled SBR sample, the mechanical strengths of the prepared Ti3C2-g-SiO2 filled SBR sample are dramatically enhanced, including tensile strength (enhanced by 244%, from 4.09 to 14.1 MPa) and elongation at break (enhanced by 93%, from 271 to 522%). More importantly, the Ti3C2-g-SiO2 filled SBR sample featuring excellent electrical (8.96 × 10−4 S m−1) and thermal conductivities (0.449 W m−1 k−1), which could exceed the reduced graphene oxide filled SBR sample.
•A novel multifunctional filler is synthesized via an in-situ growing method.•The filler disperses uniformly in a single-layered state in the rubber matrix.•The interfacial interaction between filler and rubber matrix is improved.•The elastomer composites possess high mechanical performances.•The elastomer composites exhibit superior thermal and electrical conductivities.
Abstract
Conclusion: Most of the infants demonstrated rapid improvement in the three different auditory skills within the first year after switch-on. Infants undergoing hearing aid trial and ...habilitation demonstrated a significant positive effect on the development of auditory skills in comparison with infants without trial and habilitation. Objective: This paper aims to evaluate the auditory performance of infants of different age at cochlear implantation, emphasize the importance of the hearing aid trial and habilitation before implant, and provide baseline data of auditory development. Methods: In all, 259 infants with prelingually profound hearing loss participated in this study. The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) was used to assess auditory skills in infants at different intervals. Results: The mean scores for the auditory skills improved significantly over time. The mean scores of three skills for each group at each interval were significantly different. The mean scores of the auditory skills were significantly superior for infants undergoing hearing aid trial and habilitation in comparison with those of infants without hearing aid trial and habilitation.
Infectious bronchitis virus (IBV) is first to be discovered coronavirus which is probably endemic in all regions with intensive impact on poultry production. In this study, we used two-dimensional ...gel electrophoresis (2-DE) and two-dimensional fluorescence difference gel electrophoresis (2-DIGE), coupled with matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS), to explore the global proteome profiles of trachea and kidney tissues from chicken at different stages infected in vivo with the highly virulent ck/CH/LDL/97I P5 strain of infectious bronchitis virus (IBV) and the embryo-passaged, attenuated ck/CH/LDL/97I P115 strain.
Fifty-eight differentially expressed proteins were identified. Results demonstrated that some proteins which had functions in cytoskeleton organization, anti-oxidative stress, and stress response, showed different change patterns in abundance from chicken infected with the highly virulent ck/CH/LDL/97I P5 strain and those given the embryo-passaged, attenuated P115 stain. In addition, the dynamic transcriptional alterations of 12 selected proteins were analyzed by the real-time RT-PCR, and western blot analysis confirmed the change in abundance of heat shock proteins (HSP) beta-1, annexin A2, and annexin A5.
The proteomic alterations described here may suggest that these changes to protein expression correlate with IBV virus' virulence in chicken, hence provides valuable insights into the interactions of IBV with its host and may also assist with investigations of the pathogenesis of IBV and other coronavirus infections.
Using conditional knock-in mouse models, we and others have shown that despite the very high sequence identity between Nras and Kras proteins, oncogenic Kras displays a much stronger leukemogenic ...activity than oncogenic Nras in vivo. In this manuscript, we will summarize our recent work of characterizing wild-type Kras function in adult hematopoiesis and in oncogenic Kras-induced leukemogenesis. We attribute the strong leukemogenic activity of oncogenic Kras to 2 unique aspects of Kras signaling. First, Kras is required in mediating cell type- and cytokine-specific ERK1/2 signaling. Second, oncogenic Kras, but not oncogenic Nras, induces hyperactivation of wild-type Ras, which significantly enhances Ras signaling in vivo. We will also discuss a possible mechanism that mediates oncogenic Kras-evoked hyperactivation of wild-type Ras and a potential approach to down-regulate oncogenic Kras signaling.
Abstract
Conclusion: This study indicates that Mandarin-speaking subjects acquire significant benefit from a cochlear implant (CI) and audio processor with the fine structure processing (FSP) coding ...strategy. It can take adult Mandarin CI users time to become accustomed to their CI and appreciate the benefits. Objectives: This study aimed to determine speech perception outcomes in Mandarin-speaking adults who received the FSP coding strategy. Methods: This was a prospective study. Ten adults who were implanted unilaterally with a PULSARCI100, and received an OPUS 1 or OPUS 2 speech processor, were included in this study. The mean age at implantation was 31.1 years. We determined the benefit to postlingually deafened Mandarin-speaking adults with a severe to profound hearing loss using the tests: monosyllables in quiet, sentences in quiet and the Mandarin Hearing in Noise Test (MHINT). Tone perception was evaluated using a tone perception test. A visual analog scale (VAS) was used to score sound quality and ease of listening. Results: The results showed a significant improvement between first fitting and 6 months in all speech tests and in tone perception. The VAS scores showed a significant improvement over 6 months in sound quality and an immediate benefit in ease of listening.
The purpose of this study was to examine the open-set word recognition performance of Mandarin Chinese-speaking children who had received a multichannel cochlear implant (CI) and examine the effects ...of lexical characteristics and demographic factors (i.e., age at implantation and duration of implant use) on Mandarin Chinese open-set word recognition in these children.
Participants were 230 prelingually deafened children with CIs. Age at implantation ranged from 0.9 to 16.0 years, with a mean of 3.9 years. The Standard-Chinese version of the Monosyllabic Lexical Neighborhood test and the Multisyllabic Lexical Neighborhood test were used to evaluate the open-set word identification abilities of the children. A two-way analysis of variance was performed to delineate the lexical effects on the open-set word identification, with word difficulty and syllable length as the two main factors. The effects of age at implantation and duration of implant use on open-set, word-recognition performance were examined using correlational/regressional models.
First, the average percent-correct scores for the disyllabic "easy" list, disyllabic "hard" list, monosyllabic "easy" list, and monosyllabic "hard" list were 65.0%, 51.3%, 58.9%, and 46.2%, respectively. For both the easy and hard lists, the percentage of words correctly identified was higher for disyllabic words than for monosyllabic words, Second, the CI group scored 26.3%, 31.3%, and 18.8 % points lower than their hearing-age-matched normal-hearing peers for 4, 5, and 6 years of hearing age, respectively. The corresponding gaps between the CI group and the chronological-age-matched normal-hearing group were 47.6, 49.6, and 42.4, respectively. The individual variations in performance were much greater in the CI group than in the normal-hearing group, Third, the children exhibited steady improvements in performance as the duration of implant use increased, especially 1 to 6 years postimplantation. Last, age at implantation had significant effects on postimplantation word-recognition performance. The benefit of early implantation was particularly evident in children 5 years old or younger.
First, Mandarin Chinese-speaking pediatric CI users' open-set word recognition was influenced by the lexical characteristics of the stimuli. The score was higher for easy words than for hard words and was higher for disyllabic words than for monosyllabic words, Second, Mandarin-Chinese-speaking pediatric CI users exhibited steady progress in open-set word recognition as the duration of implant use increased. However, the present study also demonstrated that, even after 6 years of CI use, there was a significant deficit in open-set, word-recognition performance in the CI children compared with their normal-hearing peers. Third, age at implantation had significant effects on open-set, word-recognition performance. Early implanted children exhibited better performance than children implanted later.
Abstract
Conclusion: The study demonstrates that two methods of segmentation, i.e. word and character segmentations, produce equivalent results in the Mandarin Hearing in Noise Test (MHINT). ...Potentially, both methods of segmentation can be used clinically. A majority of the Mandarin-speaking cochlear implant subjects could complete MHINT - with the more relaxed adaptive rules. The results make it possible to compare the performance of cochlear implant users across languages. Objectives: The primary purpose of the present study was to evaluate the modified adaptive scoring rules and to develop alternative methods of segmentations in MHINT that are suitable for the Chinese language. Methods: Thirty Mandarin-speaking normal-hearing adults were tested with MHINT using three adaptive rules based on character and/or word segmentation of the sentences. Twenty-three Mandarin-speaking post-lingually deafened cochlear implant patients were also recruited to participate in the testing. Results: There were no significant differences in the reception threshold for sentences and speech recognition scores obtained with either method of segmentation (p > 0.05). Fifteen of the 23 cochlear implant subjects (65%) could be tested with the modified adaptive scoring rules. The performance-intensity functions of the cochlear implant subjects were shifted at least 8−10 dB to higher signal-to-noise ratios as compared with those of the normal-hearing subjects.
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