188 research outputs found

    Sequential emitter identification method based on D-S evidence theory

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    This paper proposes a novel sequential identification method for enhancing the anti-jamming performance and for accurate recognition rate of the emitters’ individual identification in the complicated environment. The proposed method integrates the D-S evidence theory and features extraction that can get the utmost out of features of information systems and decrease the influence of uncertain factors in the signal processing. Firstly, selected features are extracted from intercepted signals. Then, the proposed self-adaptive fusing rule based on the decision vector is utilized to fuse the evidences that are transformed by features and the previous fusing information. Finally, recognition results can be obtained by judgment rules. The simulation analysis demonstrates that self-adaptive fusing rule can achieve a great balance between computational efficiency and accurate identifying rate. While comparing with other identifying methods, the proposed sequential identifying method can provide more accurate and stable recognition results, which makes the utmost care and use of existing information

    Decadal Variation in Surface Characteristics over Xinjiang, Western China, from T/P Altimetry Backscatter Coefficients: Evidence of Climate Change

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    The backscatter coefficient, known as sigma0, is an important measurement of satellite radar altimetry and a key parameter for land altimetry because of its close relationship with the physical properties and geometric features of land coverage under global/regional climate change effects. Using the TOPEX/Poseidon GDR-M dataset from January 1993 to December 2004, we study the spatial and temporal distribution of sigma0 at bands Ku and C over Xinjiang, western China. The results show that the sigma0 is influenced by the water distribution over land and the time evolution of sigma0 has clear seasonal changes. River basins or deserts are classified over the spatial distribution based on different sigma0 values. For example, high sigma0 values are found in the Tarim River Basin and low values are found in the Taklimakan Desert. The periodic components of sigma0 time series are determined using the fast Fourier transformation method. The annual variation is the dominating cycle and the semi-annual variation is the secondary signal. The amplitudes of sigma0 time series at bands Ku and C are also given and most areas have quite low amplitudes except for the Tarim River Basin. Several areas including the Tarim River Basin, Tianshan Mountain and Taklimakan Desert are selected for sigma0 time series spacial analysis to discuss the reasons for variations in sigma0. The main factors are precipitation and vegetation growth, which are affected by the global/regional climate change. The correlation between the brightness temperature, which is related to the water-vapor content in the atmosphere measured by TMR at the 21 GHz channel and sigma0 at two bands, is analyzed

    Measurement of small rotation angle of flange joints by a novel flexure magnifying mechanism

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    Bolted flange joints are indispensable components in process industries due to the good sealing, assemble and disassemble capacities. Generally, the flange rigidity characterized by the rotation angle is a key index to evaluate the sealing tightness of flange joints. However, the rotation angle of flange is usually too small (less than 1Âş) to monitor during the assemble and operation stages. Accordingly, a novel flexure magnifying mechanism is designed to measure the small rotation angle of flange joints under internal pressure and external bending moment. The magnification factor and calculation approach of the flexure amplification mechanism are deduced and verified by experimental data and finite element simulation. Results indicate that the proposed measuring apparatus has good performance to monitor the maximum rotation angle. It is of great interest that the measured location of the maximum rotation angle is in good agreement with that in the experiment, and the average error is 7.3%, which is acceptable for practical application. Additionally, the leakage rate at the top of flange joints slowly and almost linearly increases with the increment of external bending moment ascribing to the decrease the gasket stress near the top of flange joints

    Correlation and entanglement of two-component Bose-Einstein condensates in a double well

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    We consider a novel system of two-component atomic Bose-Einstein condensate in a double-well potential. Based on the well-known two-mode approximation, we demonstrate that there are obvious avoided level-crossings when both interspecies and intraspecies interactions of two species are increased. The quantum dynamics of the system exhibits revised oscillating behaviors compared with a single component condensate. We also examine the entanglement of two species. Our numerical calculations show the onset of entanglement can be signed as a violation of Cauchy-Schwarz inequality of second-order cross correlation function. Consequently, we use Von Neumann entropy to quantity the degree of entanglement

    SDN-controlled and Orchestrated OPSquare DCN Enabling Automatic Network Slicing with Differentiated QoS Provisioning

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    In this work, we propose and experimentally assess the automatic and flexible NSs configurations of optical OPSquare DCN controlled and orchestrated by an extended SDN control plane for multi-tenant applications with differentiated QoS provisioning. Optical Flow Control (OFC) protocol has been developed to prevent packet losses at switch sides caused by packet contentions.Based on the collected resource topology of data plane, the optical network slices can be dynamically provisioned and automatically reconfigured by the SDN control plane. Meanwhile, experimental results validate that the priority assignment of application flows supplies dynamic QoS performance to various slices running applications with specific requirements in terms of packet loss and transmission latency. In addition, the capability of exposing traffic statistics information of data plane to SDN control plane enables the implementation of load balancing algorithms further improving the network performance with high QoS. No packet loss and less than 4.8 us server-to-server latency can be guaranteed for the sliced network with highest priority at a load of 0.5

    A novel CT-guided technique using medical adhesive for localization of small pulmonary ground-glass nodules and mixed ground-glass nodules (≤20 mm) before video-assisted thoracoscopic surgery

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    PURPOSE:We aimed to evaluate the success rate and complication occurrence of CT-guided localization of small pure ground-glass nodules (pGGNs) and mixed ground-glass nodules (mGGNs) with medical adhesive injection before video-assisted thoracoscopic surgery (VATS).METHODS:From March 2015 to May 2017, 41 patients with 44 small pGGNs and mGGNs underwent CT-guided percutaneous localization with medical adhesive prior to wedge resection by VATS.RESULTS:Localization with medical adhesive was successful in all patients (100%). The nodules (13 pGGNs, 31 mGGNs) had a mean maximal long-axis diameter of 9±4 mm and a mean distance of 10±7 mm from the most superficial edge of the nodule to the visceral pleura. The localization time was 16±8 minutes. There was a moderate inverse relationship between localization time and the nodule diameter (r= -0.42, P = 0.005). Thirty-three nodules with primary lung cancer were pathologically confirmed. There were 3 cases of pneumothorax (7%), 3 cases of parenchyma hemorrhage (7%) and 2 cases of irritable cough (5%), respectively. No conversion to thoracotomy was necessary in any patient.CONCLUSION:CT-guided percutaneous localization with medical adhesive can label small pGGNs and mGGNs prior to VATS, with high success and low complication rates

    Genome plasticity of Vibrio parahaemolyticus: microevolution of the 'pandemic group'

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    <p>Abstract</p> <p>Background</p> <p>Outbreak of <it>V. parahaemolyticus </it>infections occurred since 1996 was linked to a proposed clonal complex, the pandemic group. The whole genome sequence provides an unprecedented opportunity for dissecting genome plasticity and phylogeny of the populations of <it>V. parahaemolyticus</it>. In the present work, a whole-genome cDNA microarray was constructed to compare the genomic contents of a collection of 174 strains of <it>V. parahaemolyticus</it>.</p> <p>Results</p> <p>Genes that present variably in the genome accounted for about 22% of the whole gene pool on the genome. The phylogenetic analysis of microarray data generated a minimum spanning tree that depicted the phylogenetic structure of the 174 strains. Strains were assigned into five complexes (C1 to C5), and those in each complex were related genetically and phylogenetically. C3 and C4 represented highly virulent clinical clones. C2 and C3 constituted two different clonal complexes 'old-O3:K6 clone' and 'pandemic clone', respectively. C3 included all the 39 pandemic strains tested (<it>trh</it><sup>-</sup>, <it>tdh</it><sup>+ </sup>and GS-PCR<sup>+</sup>), while C2 contained 12 pre-1996 'old' O3:K6 strains (<it>trh</it><sup>+</sup>, <it>tdh</it><sup>- </sup>and GS-PCR<sup>-</sup>) tested herein. The pandemic clone (post-1996 'new' O3:K6 and its derivates O4:K68, O1:K25, O1:KUT and O6:K18) might be emerged from the old-O3:K6 clone, which was promoted by acquisition of <it>toxRS</it>/new sequence and genomic islands. A phylogenetic intermediate O3:K6 clade (<it>trh</it><sup>-</sup>, <it>tdh</it><sup>- </sup>and GS-PCR<sup>+</sup>) was identified between the pandemic and old-O3:K6 clones.</p> <p>Conclusion</p> <p>A comprehensive overview of genomic contents in a large collection of global isolates from the microarray-based comparative genomic hybridization data enabled us to construct a phylogenetic structure of <it>V. parahaemolyticus </it>and an evolutionary history of the pandemic group (clone) of this pathogen.</p

    Vestibular Function in Children and Adults Before and After Unilateral or Sequential Bilateral Cochlear Implantation

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    Background: Cochlear implantation (CI) helps patients with severe or profound sensorineural hearing loss (SNHL) restore hearing and speech abilities. However, some patients exhibit abnormal vestibular functions with symptoms such as dizziness or balance disorders, after CI. Whether age at CI and CI approach (unilateral or sequential bilateral) affect vestibular functions in users with cochlear implants remains unclear.Objectives: To investigate the vestibular functions in children and adults before and after unilateral or sequential bilateral CI.Materials and Methods: Thirty-seven patients with severe or profound SNHL who were candidates for a first- or second-side CI were divided into three groups: first-side CI-implanted adults (≥18 years), first-side CI-implanted children (6–17 years), and second-side CI-implanted children (6–17 years). All cases were implanted with the round window approach to minimize damage to the intra-cochlear structures. The caloric test, vestibular evoked myogenic potential (VEMP) test, video head impulse test (vHIT), Dizziness Handicap Inventory (DHI), Pediatric Vestibular Symptom Questionnaire (PVSQ), and audiometric tests were performed before and 1 month after CI.Results: The abnormal rates of caloric test and VEMP test after CI in the first-side CI-implanted adults and children significantly increased compared with those before CI. The pre-implantation VEMP test showed significantly higher abnormal rates between first- and second-side CI-implanted children. No other significant differences of abnormal rates between first- and second-side CI-implanted children or between first-side CI-implanted adults and children were found. In second-side CI-implanted children, PVSQ scores significantly increased at day 3 post-implantation but decreased at day 30.Conclusion: CI has a negative effect on the results of caloric and VEMP tests, but not on vHIT, indicating that the otolith and low-frequency semicircular canal (SCC) are more vulnerable to damage from CI. The alterations of vestibular functions resulting from CI surgery may be independent of age at CI and CI approach (unilateral or sequential bilateral). Long-term impacts on the vestibular function from CI surgery, as well as the chronic electrical stimulation to the cochlea, are still to be investigated
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