9 research outputs found

    a three-level verification approach on wireless communication controller system

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    Wireless Communication Controller System is an industrial communication system that controls multiple categories of radios to communicate with remote systems. Due to high cost and great uncertainty in this wireless system test, we present our work in terms of formally modeling, verifying and improving the system. To deal with the complexity of concurrent system verification, we propose a three-level verification method, from the lowest function view to secondary component view and then to the highest system view. By SPIN model checker, we have discovered some deadlock scenarios and boundary-value errors in the system. After being corrected, the system demonstrates well behaviors in the next step of verification. © 2011 IEEE.IEEEWireless Communication Controller System is an industrial communication system that controls multiple categories of radios to communicate with remote systems. Due to high cost and great uncertainty in this wireless system test, we present our work in terms of formally modeling, verifying and improving the system. To deal with the complexity of concurrent system verification, we propose a three-level verification method, from the lowest function view to secondary component view and then to the highest system view. By SPIN model checker, we have discovered some deadlock scenarios and boundary-value errors in the system. After being corrected, the system demonstrates well behaviors in the next step of verification. © 2011 IEEE

    tree-based service discovery in mobile ad hoc networks

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    Institute of Electrical and Electronics Engineers; IEEE Computer Society; IEEE Comput. Soc. Tech. Comm. Serv. Comput. (TCSC); Natural Science Foundation of China; Hangzhou Dianzi UniversityUtilizing service oriented architectures to enhance seamless collaborations and information sharing among nodes in mobile ad hoc networks with limited communication capability is a challenging task. In this paper a novel tree-based service discovery mechanism, able to achieve high accuracy in the process of service discovery, is proposed, which affords wireless communication overheads nearly linear with the number of property-changing services offered by the whole network. The mechanism is suitable and customized for typical mobile networks. As properties such as quality and capability of the aimed services are always changing rather than remaining invariable, a service matching process is also provided, where an efficient method is implemented for searching for a target service in a local service repository with given conditions and policies

    Dynamic Disintegration of Explosively-Driven Metal Cylinder with Internal V-Grooves

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    Machining V-shaped grooves to the internal surface of cylindrical shells is one of the most common technologies of controlled fragmentation for improving warhead lethality against targets. The fracture strain of grooved shells is a significant concern in warhead design. However, there is as yet no reasonable theory for predicting the fracture strain of a specific grooved shell; existing approaches are only able to predict this physical regularity of non-grooved shells. In this paper, through theoretical analysis and numerical simulations, a new model was established to study the fracture strain of explosively driven cylindrical shells with internal longitudinal V-grooves. The model was built based on an energy conservation equation in which the energy consumed to create a new fracture surface in non-grooved shells was provided by the elastic deformation energy stored in shells. We modified the energy approach so that it can be applicable to grooved shells by adding the elastic energy liberated for crack penetration and reducing the required fracture energy. Cylinders with different groove geometric parameters were explosively expanded to the point of disintegration to verify the proposed model. Theoretical predictions of fracture strain showed good agreement with experimental results, indicating that the model is suitable for predicting the fracture strain of explosively driven metal cylinders with internal V-grooves. In addition, this study provides an insight into the mechanism whereby geometric defects promote fracturing

    Acceleration Characteristics of Discrete Fragments Generated from Explosively-Driven Cylindrical Metal Shells

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    The acceleration characteristics of fragments generated from explosively-driven cylindrical shells are important issues in warhead design. However, there is as yet no reasonable theory for predicting the acceleration process of a specific metallic shell; existing approaches either ignore the effects of shell disintegration and the subsequent gas leakage on fragment acceleration or treat them in a simplified manner. In this paper, a theoretical model was established to study the acceleration of discrete fragments under the combined effect of shell disintegration and gas leakage. Firstly, an equation of motion was developed, where the acceleration of a cylindrical shell and the internal detonation gas was determined by the motive force impacting the inner surface of the metallic cylinder. To account for the force decrease induced by both the change in fragment area after the shell disintegrates and the subsequent drop in gas pressure due to gas leakage, the equation of motion was then associated with an equation for the locally isentropic expansion of the detonation gas and a modified gas-leakage equation. Finally, theoretical analysis was conducted by solving the associated differential equations. The proposed model showed good agreement with experimental data and numerical simulations, indicating that it was suitable for predicting the acceleration of discrete fragments generated from a disintegrated warhead shell. In addition, this study facilitated a better understanding of the complicated interaction between fragment acceleration and gas outflow

    Upregulation of Nav1.6 Mediated by the p38 MAPK Pathway in the Dorsal Root Ganglia Contributes to Cancer-Induced Bone Pain in Rats

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    Cancer-induced bone pain (CIBP) occurs frequently among advanced cancer patients. Voltage-gated sodium channels (VGSCs) have been associated with chronic pain, but how VGSCs function in CIBP is poorly understood. Here, we aimed to investigate the specific role of VGSCs in the dorsal root ganglia (DRGs) in CIBP. A CIBP rat model was generated by the intratibial inoculation of MRMT-1 breast carcinoma cells. Transcriptome sequencing was conducted to assess the gene expression profiles. The expression levels of key genes and differentiated genes related to activated pathways were measured by Western blotting and qPCR. We implanted a catheter intrathecally for the administration of lentivirus and drugs. Then, the changes in the mechanical withdrawal threshold (MWT) were measured. We identified 149 differentially expressed mRNAs (DEmRNAs) in the DRGs of CIBP model rats. The expression of Nav1.6, which was among these DEmRNAs, was significantly upregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the DEmRNAs showed that they were mainly enriched in the mitogen-activated protein kinase (MAPK) pathway. The decrease in MWT induced by bone cancer was attenuated by Nav1.6 knockdown. Western blot analysis revealed that a p38 inhibitor decreased the expression of Nav1.6 and attenuated pain behavior. Our study shows that the upregulation of Nav1.6 expression by p38 MAPK in the DRGs of rats contributes to CIBP

    InDels Identification and Association Analysis with Spike and Awn Length in Chinese Wheat Mini-Core Collection

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    Diversity surveys of germplasm are important for gaining insight into the genomic basis for crop improvement; especially InDels, which are poorly understood in hexaploid common wheat. Here, we describe a map of 89,923 InDels from exome sequencing of 262 accessions of a Chinese wheat mini-core collection. Population structure analysis, principal component analysis and selective sweep analysis between landraces and cultivars were performed. Further genome-wide association study (GWAS) identified five QTL (Quantitative Trait Loci) that were associated with spike length, two of them, on chromosomes 2B and 6A, were detected in 10 phenotypic data sets. Assisted with RNA-seq data, we identified 14 and 21 genes, respectively that expressed in spike and rachis within the two QTL regions that can be further investigated for candidate genes discovery. Moreover, InDels were found to be associated with awn length on chromosomes 5A, 6B and 4A, which overlapped with previously reported genetic loci B1 (Tipped 1), B2 (Tipped 2) and Hd (Hooded). One of the genes TaAGL6 that was previously shown to affect floral organ development was found at the B2 locus to affect awn length development. Our study shows that trait-associated InDels may contribute to wheat improvement and may be valuable molecular markers for future wheat breedin

    Hierarchical porous ECM scaffolds incorporating GDF-5 fabricated by cryogenic 3D printing to promote articular cartilage regeneration

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    Abstract Background In recent years, there has been significant research progress on in situ articular cartilage (AC) tissue engineering with endogenous stem cells, which uses biological materials or bioactive factors to improve the regeneration microenvironment and recruit more endogenous stem cells from the joint cavity to the defect area to promote cartilage regeneration. Method In this study, we used ECM alone as a bioink in low-temperature deposition manufacturing (LDM) 3D printing and then successfully fabricated a hierarchical porous ECM scaffold incorporating GDF-5. Results Comparative in vitro experiments showed that the 7% ECM scaffolds had the best biocompatibility. After the addition of GDF-5 protein, the ECM scaffolds significantly improved bone marrow mesenchymal stem cell (BMSC) migration and chondrogenic differentiation. Most importantly, the in vivo results showed that the ECM/GDF-5 scaffold significantly enhanced in situ cartilage repair. Conclusion In conclusion, this study reports the construction of a new scaffold based on the concept of in situ regeneration, and we believe that our findings will provide a new treatment strategy for AC defect repair
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