An Improved Weight Optimization AAIM Method Aided by Barometric Altimeter

Xiaowei Xu,Jizhou Lai,Min Liu,Zhiming Zheng,Yuting Dai,Kai Huang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.3

Aiming at the problem of insufficient availability in the satellite receiver autonomous integrity monitoring (RAIM) method, an improved aircraft autonomous integrity monitoring (AAIM) method aided by barometric altimeter based on weight optimization is proposed under the actual configuration of the airborne navigation system. The information of satellite navigation system and barometric altimeter is used to establish the observation equation of the integrated system. The algorithm for integrity monitoring and protection-level calculation is derived based on multiple solution separation, and a weight optimization is adopted to achieve a trade-off between position accuracy and integrity, which can improve the availability of AAIM method. The simulation experiment shows that when the number of visible stars is 5, the traditional method cannot effectively detect the satellite fault, and the positioning error is 43.65 m. The improved algorithm can effectively isolate the fault and reduce the positioning error to 0.37 m. Compared with the traditional RAIM algorithm and the Baro-aided AAIM algorithm, the proposed algorithm has a lower vertical protection threshold. Therefore, the algorithm in this paper improves the performance of satellite navigation system integrity monitoring and ensure the accuracy and reliability of the satellite navigation system.

Optimization and application of multiple tuned mass dampers in the vibration control of pedestrian bridges

Zheng Lu,Xiaoyi Chen,Xiaowei Li,Peizhen Li 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.1

An effective design approach for Multiple Tuned Mass Dampers (MTMDs) in pedestrian bridges was proposed by utilizing the transfer function to obtain each TMD’s optimum stiffness and damping. A systematic simulation of pedestrian excitations was described. The motion equation of a typical MTMD system attached to a Multi-degree-of-freedom (MDOF) system was presented, and the transfer function from the input pedestrian excitations to the output acceleration responses was defined. By solving the minimum norm of the transfer function, the parameters of the MTMD which resulted in the minimum overall responses can be obtained. Two applications of lightly damped pedestrian bridges attached with MTMD showed that MTMDs designed through this method can significantly reduce the structural responses when subjected to pedestrian excitations, and the vibration control effects were better than the MTMD when it was considered as being composed of equal number and mass ratios of TMDs designed by classical Den Hartog method.

Risk Factors of Rehemorrhage in Postoperative Patients with Spontaneous Intracerebral Hemorrhage : A Case-Control Study

Ren, Yanming,Zheng, Jun,Liu, Xiaowei,Li, Hao,You, Chao The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.1

Objective : Rehemorrhage is the most severe complication of postoperative patients with spontaneous intracerebral hemorrhage. The aim of the present study was to assess independent predictors of rehemorrhage and find the possibility of preventing rehemorrhage in postoperative patients with spontaneous intracerebral hemorrhage (sICH). Methods : Medical records of 263 postoperative patients with sICH from our Hospital were reviewed. The relationships between rehemorrhage and parameters were examined by univariate and multivariate analyses. The parameters include time from onset to surgery, hematologic paremeters, neuroimaging characteristics, level and variability of systolic blood pressure, medical histories, operation duration, and blood loss. In addition, relationship between rehemorrhage and clinical outcome were analyzed by using multivariate analyses. Results : Thirty-five (13.31%) patients experienced rehemorrhage after operation. Multivariate analyses indicated that the following factors were independently associated with rehemorrhage : history of diabetes mellitus (odds ratio [OR], 2.717; 95% confidence interval [CI], 1.005-7.346; p=0.049), and midline shift (for every 1 mm increase, OR, 1.117; 95% CI, 1.029-1.214; p=0.009). Rehemorrhage was an independent risk factor of poor functional outcome (OR, 3.334; 95% CI, 1.094-10.155; p=0.034). Conclusion : Our finding revealed that history of diabetes mellitus and admission midline shift were possibly associated with rehemorrhage in postoperative patients with sICH.

The Gene Polymorphism of VMAT2 Is Associated with Risk of Schizophrenia in Male Han Chinese

Hongying Han,Xiaowei Xia,Huirong Zheng,Chongbang Zhao,Yanming Xu,Jiong Tao,Xianglan Wang 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.11

Objective To investigate the association between gene polymorphism of vesicular monoamine transporter type 2(VMAT2) and schizophrenia in Han Chinese population.Methods 430 patients with schizophrenia and 470 age-sex matched controls were recruited from four mental health centers. All patients were diagnosed by two psychiatrists based on the Structured Clinical Interview for DSM Disorders (SCID). The ligase detection reactions (LDR) method was used to assess the polymorphism of the two SNPs (rs363371 and rs363324) of VMAT2.Results No associations of two SNPs with schizophrenia was found. When we stratified males and females for the analysis, we found that that in the recessive model of rs363371, there was an obvious significant association between rs363371 and schizophrenia in males (OR=0.564, 95% CI=0.357–0.892, p=0.014) but not females. For the association between rs363324 and schizophrenia, no association was found in either males or females. No association was found when stratifying early-onset schizophrenia and late-onset schizophrenia.Conclusion Our findings indicate that both rs363371 and rs363324 were not associated with schizophrenia, while it seemed that the AA genotype of rs363371 plays a protective effect in male Chinese in developing schizophrenia.

Molecular Signature That Determines the Acute Tolerance of G Protein-Coupled Receptors

Min, Chengchun,Zhang, Xiaohan,Zheng, Mei,Sun, Ningning,Acharya, Srijan,Zhang, Xiaowei,Kim, Kyeong-Man The Korean Society of Applied Pharmacology 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.3

Desensitization and acute tolerance are terms used to describe the attenuation of receptor responsiveness by prolonged or intermittent exposure to an agonist. Unlike desensitization of G protein-coupled receptors (GPCRs), which is commonly explained by steric hindrance caused by the ${\beta}$-arrestins that are translocated to the activated receptors, molecular mechanisms involved in the acute tolerance of GPCRs remain unclear. Our studies with several GPCRs and related mutants showed that the acute tolerance of GPCRs could occur independently of agonist-induced ${\beta}$-arrestin translocation. A series of co-immunoprecipitation experiments revealed a correlation between receptor tolerance and interactions among receptors, ${\beta}$-arrestin2, and $G{\beta}{\gamma}$. $G{\beta}{\gamma}$ displayed a stable interaction with receptors and ${\beta}$-arrestin2 in cells expressing GPCRs that were prone to undergo tolerance compared to the GPCRs that were resistant to acute tolerance. Strengthening the interaction between $G{\beta}{\gamma}$ and ${\beta}$-arrestin rendered the GPCRs to acquire the tendency of acute tolerance. Overall, stable interaction between the receptor and $G{\beta}{\gamma}$ complex is required for the formation of a complex with ${\beta}$-arrestin, and determines the potential of a particular GPCR to undergo acute tolerance. Rather than turning off the signal, ${\beta}$-arrestins seem to contribute on continuous signaling when they are in the context of complex with receptor and $G{\beta}{\gamma}$.

Molecular Signature That Determines the Acute Tolerance of G Protein-Coupled Receptors

( Chengchun Min ),( Xiaohan Zhang ),( Mei Zheng ),( Ningning Sun ),( Srijan Acharya ),( Xiaowei Zhang ),( Kyeong-man Kim ) 한국응용약물학회 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.3

Desensitization and acute tolerance are terms used to describe the attenuation of receptor responsiveness by prolonged or intermittent exposure to an agonist. Unlike desensitization of G protein-coupled receptors (GPCRs), which is commonly explained by steric hindrance caused by the β-arrestins that are translocated to the activated receptors, molecular mechanisms involved in the acute tolerance of GPCRs remain unclear. Our studies with several GPCRs and related mutants showed that the acute tolerance of GPCRs could occur independently of agonist-induced β-arrestin translocation. A series of co-immunoprecipitation experiments revealed a correlation between receptor tolerance and interactions among receptors, β-arrestin2, and Gβγ. Gβγ displayed a stable interaction with receptors and b-arrestin2 in cells expressing GPCRs that were prone to undergo tolerance compared to the GPCRs that were resistant to acute tolerance. Strengthening the interaction between Gβγ and β-arrestin rendered the GPCRs to acquire the tendency of acute tolerance. Overall, stable interaction between the receptor and Gβγ complex is required for the formation of a complex with β-arrestin, and determines the potential of a particular GPCR to undergo acute tolerance. Rather than turning off the signal, β-arrestins seem to contribute on continuous signaling when they are in the context of complex with receptor and Gβγ.

Experimental study on shear, tensile, and compression behaviors of composite insulated concrete sandwich wall

Zhang, Xiaomeng,Zhang, Xueyong,Liu, Wenting,Li, Zheng,Zhang, Xiaowei,Zhou, Yilun Techno-Press 2021 Advances in concrete construction Vol.11 No.1

A new type of composite insulated concrete sandwich wall (ICS-wall), which is composed of a triangle truss steel wire network, an insulating layer, and internal and external concrete layers, is proposed. To study the mechanical properties of this new ICS-wall, tensile, compression, and shearing tests were performed on 22 specimens and tensile strength and corrosion resistance tests on 6 triangle truss joints. The variables in these tests mainly include the insulating plate material, the thickness of the insulating plate, the vertical distance of the triangle truss framework, the triangle truss layout, and the connecting mode between the triangle truss and wall and the material of the triangle truss. Moreover, the failure mode, mechanical properties, and bearing capacity of the wall under tensile, shearing, and compression conditions were analyzed. Research results demonstrate that the concrete and insulating layer of the ICS-wall are pulling out, which is the main failure mode under tensile conditions. The ICS-wall, which uses a graphite polystyrene plate as the insulating layer, shows better tensile properties than the wall with an ordinary polystyrene plate. The tensile strength and bearing capacity of the wall can be improved effectively by strengthening the triangle truss connection and shortening the vertical distances of the triangle truss. The compression capacity of the wall is mainly determined by the compression capacity of concrete, and the bonding strength between the wall and the insulating plate is the main influencing factor of the shearing capacity of the wall. According to the tensile strength and corrosion resistance tests of Austenitic stainless steel, the bearing capacity of the triangle truss does not decrease after corrosion, indicating good corrosion resistance.

Depositional and diagenetic controls on the reservoir quality of Upper Triassic Chang-7 tight oil sandstones, southwestern Ordos basin, China

Ai Wang,Dakang Zhong,Haihua Zhu,Lele Guo,Zhuopei Li,Yangjinfeng Jiang,Xueqi Yang,Rui Xie,Xiaowei Zheng 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.3

The seventh oil layer of the Upper Triassic Yanchang Formation (Chang-7) tight oil sandstone reservoirs is a major exploration target. A significant amount of hydrocarbons has been discovered in these reservoirs in the southwestern Ordos basin in China. The Chang-7 tight sandstones are characterised as tight with low porosity, low permeability, and strong heterogeneity. This study investigates the sedimentary facies, diagenesis, and their impact on the reservoir quality of the Chang-7 tight oil sandstones. The sandstones were deposited in a deltaic-lacustrine depositional system. Three major depositional facies are identified consisting of delta front fed by braided rivers and meandering rivers, and slump turbidite fans. The depositional environment exerts a key control on reservoir quality. The distinct low-energy sedimentary environment produced fine to very fine-grained sandstones with high matrix and mica contents, characterised by low initial porosity and permeability. Diagenesis mainly comprised mechanical compaction and cementation by quartz, carbonate minerals and various clay minerals. The reservoir properties of the Chang-7 sandstones are generally poor, with porosity of 1.4–20.7% (average porosity 8.6%) and permeability of 0.001–116.7 mD (average 0.2 mD), which are attributed to significant compaction and cementation. Mechanical compaction was more important than cementation for reducing porosity, whereas secondary dissolution porosity was significant for the Chang-7 tight oil sandstones due to closer proximity to the underlying Chang-73 source rocks.