WiFi Indoor Positioning and Tracking Algorithm Based on Compressive Sensing and Sage-Husa Adaptive Kalman Filter

Aiming at the problem that the positioning accuracy of WiFi indoor positioning technology based on location fingerprint has not reached the requirements of practical application, a WiFi indoor positioning and tracking algorithm combining adaptive affine propagation (AAPC), compressed sensing (CS) and Kalman filter is proposed. In the off-line phase, AAPC algorithm is used to generate clustering fingerprints with optimal clustering effect performance;In the online phase, CS and nearest neighbor algorithm are used for position estimation;Finally, the Kalman filter and physical constraints are combined to perform positioning and tracking. By collecting a large number of real experimental data, it is proved that the developed algorithm has higher positioning accuracy and more accurate trajectory tracking effect.

QoS Routing Optimization Based on Deep Reinforcement Learning in SDN

To enhance the efficiency and expediency of issuing e-licenses within the power sector, we must confront thechallenge of managing the surging demand for data traffic. Within this realm, the network imposes stringentQuality of Service (QoS) requirements, revealing the inadequacies of traditional routing allocation mechanismsin accommodating such extensive data flows. In response to the imperative of handling a substantial influx of datarequests promptly and alleviating the constraints of existing technologies and network congestion, we present anarchitecture forQoS routing optimizationwith in SoftwareDefinedNetwork (SDN), leveraging deep reinforcementlearning. This innovative approach entails the separation of SDN control and transmission functionalities, centralizingcontrol over data forwardingwhile integrating deep reinforcement learning for informed routing decisions. Byfactoring in considerations such as delay, bandwidth, jitter rate, and packet loss rate, we design a reward function toguide theDeepDeterministic PolicyGradient (DDPG) algorithmin learning the optimal routing strategy to furnishsuperior QoS provision. In our empirical investigations, we juxtapose the performance of Deep ReinforcementLearning (DRL) against that of Shortest Path (SP) algorithms in terms of data packet transmission delay. Theexperimental simulation results show that our proposed algorithm has significant efficacy in reducing networkdelay and improving the overall transmission efficiency, which is superior to the traditional methods.

超临界二氧化碳辅助挤出制备微孔醋酸纤维素

为了连续化制备泡孔结构良好的微孔二醋酸纤维素(CDA)材料,采用超临界二氧化碳(SC-CO_(2))辅助CDA挤出发泡,通过扫描电镜对微孔CDA材料断面形貌进行了观测,研究了CO_(2)注气量、螺杆转速和溶剂比对CDA泡孔形貌的影响,结果显示,随着CO_(2)注气量增加,泡孔密度从9.3×10^(7)cm^(-3)增加至1.04×10^(11)cm^(-3),平均泡孔直径从10.06μm减小至1.16μm;随着螺杆转速的提高,压降速率显著增加,泡孔密度从6.6×10^(7)cm^(-3)增加到了9.12×10^(10) cm^(-3),泡孔直径从28.1μm减小到了0.88μm;随着醇酮溶剂用量的增加,泡孔密度降低,并出现了泡孔合并现象。采用SC-CO_(2)辅助挤出发泡技术可以制备出含有致密泡孔结构的微孔CDA材料。

Effects of dynamic flow rates on degradation deposition behavior of Mg scaffold

Degradability of bone tissue engineering scaffold that matching the regeneration rate could allow a complete replacement of host tissue.However,the porous structure of biodegradable Mg scaffolds certainly generated high specific surface area,and the three-dimensional interconnected pores provided fast pervasive invasion entrance for the corrosive medium,rising concern of the structural integrity during the degradation.To clarify the structural evolution of the three-dimensional(3D)porous structure,semi-static immersion tests were carried out to evaluate the degradation performance in our previous study.Nevertheless,dynamic immersion tests mimicking the in vivo circulatory fluid through the interconnected porous structure have yet been investigated.Moreover,the effects of dynamic flow rates on the degradation deposition behavior of 3D porous Mg scaffolds were rarely reported.In this study,Mg scaffolds degraded at three flow rates exhibited different degradation rates and deposition process.A flow rate of 0.5 m L/min introduced maximum drop of porosity by accumulated deposition products.The deposition products provided limited protection against the degradation process at a flow rate of 1.0 m L/min.The three-dimensional interconnected porous structure of Mg scaffold degraded at 2.0 m L/min well retained after 14 days showing the best interconnectivity resistance to the degradation deposition process.The dynamic immersion tests disclosed the reason for the different degradation rates on account of flow rates,which may bring insight into understanding of varied in vivo degradation rates related to implantation sites.

News Keyword Extraction Algorithm Based on Semantic Clustering and Word Graph Model

The internet is an abundant source of news every day. Thus, efficient algorithms to extract keywords from the text are important to obtain information quickly. However, the precision and recall of mature keyword extraction algorithms need improvement. TextRank, which is derived from the PageRank algorithm, uses word graphs to spread the weight of words. The keyword weight propagation in Text Rank focuses only on word frequency. To improve the performance of the algorithm, we propose Semantic Clustering TextRank(SCTR), a semantic clustering news keyword extraction algorithm based on TextRank. Firstly, the word vectors generated by the Bidirectional Encoder Representation from Transformers(BERT) model are used to perform k-means clustering to represent semantic clustering. Then, the clustering results are used to construct a TextRank weight transfer probability matrix. Finally,iterative calculation of word graphs and extraction of keywords are performed. The test target of this experiment is a Chinese news library. The results of the experiment conducted on this text set show that the SCTR algorithm has greater precision, recall, and F1 value than the traditional TextRank and Term Frequency-Inverse Document Frequency(TF-IDF) algorithms.

Aquaporin-4 is a potential drug target for traumatic brain injury via aggravating the severity of brain edema

Background:Traumatic brain edema(TBE)is caused by a specific water channel mediated by membrane aquaporins.Aquaporin-4(AQP4)plays an especially important role in this process,but the relationship between AQP4 and TBE remains unclear.The purpose of this study was to explore expression of AQP4 in the hippocampus after traumatic brain injury(TBI),as well as the effect of brain edema on skeletal protein and its function in hippocampal neurons.Methods:The adult male Wistar rats we divided into a sham group and a TBI group,the latter of which was further divided into 1,3,6,12,24 and 72 hours(h)and 15 days(d)post injury subgroups.A proper TBI model was established,and brain edema was assessed in each group by water content.We measured the abundance of various proteins,including hypoxia inducible factor-1α(HIF-1α),AQP4,microtubule-associated protein 2(MAP2),tau-5 protein,phosphorylated level of TAU,synaptophysin,cyclic adenosine monophosphate response element binding protein(CREB),phosphorylated CREB and general control nonrepressed 2,in each group.Hippocampal neurons and spatial memory test were analyzed in different time points.Results:Compared with that in the sham group,the level of AQP4 in hippocampal neurons began to significantly increase at 1 h post TBI and then decreased at 15 d post TBI.During this time frame,AQP4 level peaked at 12 and 72 h,and these peaks were closely correlated with high brain water content.HIF-1αdisplayed a similar trend.Conversely,levels of MAP2 began to decrease at 1 h post TBI and then increase at 15 d post TBI.In addition,the most severe brain edema in rats was found at 24 h post TBI,with neuronal loss and hippocampal dendritic spine injury.Compared to those in the sham group,rats in the TBI groups had significantly prolonged latency and significantly shortened exploration time.Conclusions:AQP4 level was closely correlated with severity of brain edema,and abnormal levels thereof aggravated such severity after TBI.

Endoscopic decompression of the optic canal for traumatic optic neuropathy

Purpose： Traumatic optic neuropathy （TON） is a serious complication of head trauma with the incidence rate of 0.5%-5%. The aim of this study was to investigate the therapeutic efficacy of endoscopic decompression of the optic canal for optic nerve injuries. Methods： In this study, 11 patients treated in our hospital from January 2009 to January 2015 with the visual loss resulting from TON were retrospectively reviewed for preoperative vision, visual evoked potential （VEP） scan, surgical approach, postoperative visual acuity, complications, and follow-up results. Results： All these patients received endoscopic decompression of the optic canal. At the 3-month follow- up, the visual acuity improvement rate of the 11 patients was 45.5%. The vision acuity of 2 cases improved from hand movement to 0.08 and 0.3 after operation. Another patient＇s vision acuity returned to 0.05 compared to light sensation preoperatively. Two cases had finger counting before surgery but they had a vision acuity of 0.4 and light sensation respectively after surgery. However, the other 6 cases＇ vision did not improve after surgery. Conclusion： Endoscopic decompression of the optic canal is an effective way to cure TON. VEP could be used as an important reference for preoperative and prognosis evaluation. Operative time after trauma is only a relative condition that may affect the therapeutic effect of optic canal decompression. Poor results of this procedure may be related to the severity of the optic nerve injury.

Fabrication of a bio-instructive scaffold conferred with a favorable microenvironment allowing for superior implant osseointegration and accelerated in situ vascularized bone regeneration via type H vessel formation

The potential translation of bio-inert polymer scaffolds as bone substitutes is limited by the lack of neovascularization upon implantation and subsequently diminished ingrowth of host bone,most likely resulted from the inability to replicate appropriate endogenous crosstalk between cells.Human umbilical vein endothelial cell-derived decellularized extracellular matrix(HdECM),which contains a collection of angiocrine biomolecules,has recently been demonstrated to mediate endothelial cells(ECs)-osteoprogenitors(OPs)crosstalk.We employed the HdECM to create a PCL(polycaprolactone)/fibrin/HdECM(PFE)hybrid scaffold.We hypothesized PFE scaffold could reconstitute a bio-instructive microenvironment that reintroduces the crosstalk,resulting in vascularized bone regeneration.Following implantation in a rat femoral bone defect,the PFE scaffold demonstrated early vascular infiltration and enhanced bone regeneration by microangiography(μ-AG)and micro-computational tomography(μ-CT).Based on the immunofluorescence studies,PFE mediated the endogenous angiogenesis and osteogenesis with a substantial number of type H vessels and osteoprogenitors.In addition,superior osseointegration was observed by a direct host bone-PCL interface,which was likely attributed to the formation of type H vessels.The bio-instructive microenvironment created by our innovative PFE scaffold made possible superior osseointegration and type H vessel-related bone regeneration.It could become an alternative solution of improving the osseointegration of bone substitutes with the help of induced type H vessels,which could compensate for the inherent biological inertness of synthetic polymers.

Corrigendum to‘Fabrication of a bio-instructive scaffold conferred with a favorable microenvironment allowing for superior implant osseointegration and accelerated in situ vascularized bone regeneration via type H vessel formation’[Bioactive Materials,Volume 9(March 2022)Page 491-507]

The authors regret a mistake of funding numbers in the Acknowledgment Section failed to be corrected during proofreading.Below is the corrected funding statement in ACKNOWLEDGMENT SECTION:This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.82072415,81772354,81902189),Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201002),Science Technology Project of Guangzhou City(2019ZD15).