Numerical simulations of a seismic wavefield are important to analyze seismic wave propagation. Elastic-wave equations are used in data simulation for modeling migration and imaging. In elastic wavefield numerical mod...Numerical simulations of a seismic wavefield are important to analyze seismic wave propagation. Elastic-wave equations are used in data simulation for modeling migration and imaging. In elastic wavefield numerical modeling, the rotated staggered-grid method （RSM） is a modification of the standard staggered-grid method （SSM）. The variable-order method is based on the method of variable-length spatial operators and wavefield propagation, and it calculates the real dispersion error by adapting different finite-difference orders to different velocities. In this study, the variable-order rotated staggered-grid method （VRSM） is developed after applying the variable-order method to RSM to solve the numerical dispersion problem of RSM in low-velocity regions and reduce the computation cost. Moreover, based on theoretical dispersion and the real dispersion error of wave propagation calculated with the wave separation method, the application of the original method is extended from acoustic to shear waves, and the calculation is modified from theoretical to time-varying values. A layered model and an overthrust model are used to demonstrate the applicability of VRSM. We also evaluate the order distribution, wave propagation, and computation time. The results suggest that the VRSM order distribution is reasonable and VRSM produces high-precision results with a minimal computation cost.展开更多
The paper describes results obtained in the development of adaptive fuzzy-neural navigation subsystem for mobile legged robot. In order to keep the motion sufficiently smooth, free of sharp turnings and transversal sw...The paper describes results obtained in the development of adaptive fuzzy-neural navigation subsystem for mobile legged robot. In order to keep the motion sufficiently smooth, free of sharp turnings and transversal swings when moving between closely located obstacles, fuzzy rules are updated on-line. To this end, the fuzzy rules are expressed through a layered feed-forward neural network and parameters are updated on line in two steps--the rough and fine updating. That is followed by the description of the learning fault diagnosis using binary neural network based on the Carpenter and Grossbergs＇ adaptive resonance theory.展开更多
The rise of the far right in Europe has captured the attention of the international community in recent years. Its specific features are: an unprecedentedly strong influence, an obvious trend towards the moderate line...The rise of the far right in Europe has captured the attention of the international community in recent years. Its specific features are: an unprecedentedly strong influence, an obvious trend towards the moderate line, horizontal collaboration to expand its reach, and a very adept use of social media networks. The refugee crisis has given the far right an historical opportunity. The rise has also had a profound effect on European politics; it has deepened the political divide inside EU member states, and shaken up the traditional political values and the foundation of the union.The rise of the far right will likely not change Europe's political landscape, but problems of EU governance over its handling of the refugee crisis cannot be ignored.展开更多
In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairne...In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairness, revenue and cost is elaborated in WCDMA networks. Then, the optimal rate allocation problem is formulated as a network utility maximization(NUM) model based on cross-layer design and end-to-end congestion control, aiming at exploring the impacts of wired networks and the characteristics of radio access networks(RANs) on rate allocation. Furthermore, a distributed algorithm is derived, which can effectively match load states between RANs and wired networks, followed by a detailed illustration of the practical implementations. Numerical results demonstrate a signifi cant performance improvement in the end-to-end throughput.展开更多
This study measures visual attention to examine the impact of banner ads on reading and information processing on the Web. Using a 2 × 3 experimental design, 120 students were randomly assigned to read a series o...This study measures visual attention to examine the impact of banner ads on reading and information processing on the Web. Using a 2 × 3 experimental design, 120 students were randomly assigned to read a series of either short or long articles on webpages presented with no banner ads, a static banner ad, or an animated banner ad. Visual attention was recorded by an eye-tracking device. Results from our study show that when there is too little information presented on a Webpage with no banner ads, the readers might become less attentive to the paper, while a long paper presented with too many visual stimuli may overload viewers＇ cognitive capacity. While these findings are generally consistent with past research that compared the impact of static ads against animated ads, the addition of a control condition and the varying of article length in our study extended previous research by revealing more complex visual processing and cognitive processes.展开更多
Stress analysis of cylindrical grid-stiffened composite shells was conducted under transverse loading,pure bending,torsion and axial compression under clamped-free boundary condition.Electrical strain gauges were empl...Stress analysis of cylindrical grid-stiffened composite shells was conducted under transverse loading,pure bending,torsion and axial compression under clamped-free boundary condition.Electrical strain gauges were employed to measure the strains in transverse loading case to validate the finite element analysis which was conducted using ANSYS software.Good agreement was obtained between the two methods.It was observed that stiffening the composite shell with helical ribs decreased the average equivalent Von Mises stress on the shell.The reduction of the stress seemed to be higher in the intersection of two ribs.It was also seen that the stress reduction ratio was higher when the structure was under bending compared to torsion and axial compression.The reduction ratio was approximately 75% in pure bending in the intersection point of the ribs,while it was approximately 25% in torsion.Therefore,it is concluded that the presence of the ribs is more effective under bending.Failure analysis was done using Tsai-Wu criterion.The ribs were observed to result in maximum and minimum increase in the failure load of the structure under transverse bending and torsional loading,respectively.展开更多
In the present study,we aimed to assess the development of the antimicrobial stewardship(AMS)program in China’s tertiary hospitals to identify the potential challenges for the AMS program and provide references and b...In the present study,we aimed to assess the development of the antimicrobial stewardship(AMS)program in China’s tertiary hospitals to identify the potential challenges for the AMS program and provide references and benchmarks for strategic policymaking.A nationwide cross-sectional study was conducted online by sending questionnaires to tertiary hospitals under China Antimicrobial Resistance Surveillance System(CARSS).The questionnaire included 5 sections regarding structure,technical support,antimicrobial use management,antimicrobial use surveillance,and education.Descriptive statistics were used for data analysis.Of the 1044 tertiary hospitals under CARSS,13.4%(140)hospitals participated in the study.Among them,99.3%(139/140)set up the AMS program.The hospital president(82.1%,115/140)and medical service department(59.3%,83/140)were responsible for AMS outcomes in most hospitals.Structured antimicrobial formulary restriction management was adopted by 99.3%(139/140)hospitals.Infectious disease department,infection control department,and microbiological laboratories were established in 87.1%(122/140),99.3%(139/140)and 100%(140/140)hospitals,respectively.Up to 85.6%(124/140)hospitals applied clinical pathways,and 33.6%(47/140)hospitals implemented hospital-specific guidelines for infectious diseases.Outpatient prescription auditing,inpatient prescription auditing,and prophylactic antimicrobial prescription auditing of aseptic operation were performed in 99.3%(139/140),98.6%(138/140)and 95.7%(134/140)hospitals,respectively.Up to 97.1%(136/140)hospitals participated in antimicrobial use surveillance network,and 99.3%(139/140)hospitals established the specialized management of carbapenem and tigecycline.Staff education and public education were provided with various ways and frequencies in 100%(140/140)and 90.0%(126/140)hospitals,respectively.AMS programs in China’s tertiary hospitals were primarily headed by hospital presidents and involved collaboration among various disciplines and administrative departments.More efforts should be put to further promote and strengthen the development of hospital-specific guidelines and the establishment of a progress and outcome evaluation system.展开更多
基金supported by the National Science and Technology Major Project of China(No.2011ZX05004-003)the National Basic Research Program of China(No.2013CB228602)the National High Tech Research Program of China(No.2013AA064202)
文摘Numerical simulations of a seismic wavefield are important to analyze seismic wave propagation. Elastic-wave equations are used in data simulation for modeling migration and imaging. In elastic wavefield numerical modeling, the rotated staggered-grid method （RSM） is a modification of the standard staggered-grid method （SSM）. The variable-order method is based on the method of variable-length spatial operators and wavefield propagation, and it calculates the real dispersion error by adapting different finite-difference orders to different velocities. In this study, the variable-order rotated staggered-grid method （VRSM） is developed after applying the variable-order method to RSM to solve the numerical dispersion problem of RSM in low-velocity regions and reduce the computation cost. Moreover, based on theoretical dispersion and the real dispersion error of wave propagation calculated with the wave separation method, the application of the original method is extended from acoustic to shear waves, and the calculation is modified from theoretical to time-varying values. A layered model and an overthrust model are used to demonstrate the applicability of VRSM. We also evaluate the order distribution, wave propagation, and computation time. The results suggest that the VRSM order distribution is reasonable and VRSM produces high-precision results with a minimal computation cost.
文摘The paper describes results obtained in the development of adaptive fuzzy-neural navigation subsystem for mobile legged robot. In order to keep the motion sufficiently smooth, free of sharp turnings and transversal swings when moving between closely located obstacles, fuzzy rules are updated on-line. To this end, the fuzzy rules are expressed through a layered feed-forward neural network and parameters are updated on line in two steps--the rough and fine updating. That is followed by the description of the learning fault diagnosis using binary neural network based on the Carpenter and Grossbergs＇ adaptive resonance theory.
文摘The rise of the far right in Europe has captured the attention of the international community in recent years. Its specific features are: an unprecedentedly strong influence, an obvious trend towards the moderate line, horizontal collaboration to expand its reach, and a very adept use of social media networks. The refugee crisis has given the far right an historical opportunity. The rise has also had a profound effect on European politics; it has deepened the political divide inside EU member states, and shaken up the traditional political values and the foundation of the union.The rise of the far right will likely not change Europe's political landscape, but problems of EU governance over its handling of the refugee crisis cannot be ignored.
基金supported by National Natural Science Foundation of China (61172079, 61231008, 61201141, 61301176)111 Project (B08038)+1 种基金National S&T Major Project (2010ZX03003001)Shaanxi Province Science and Technology Research and Development Program (2011KJXX-40)
文摘In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairness, revenue and cost is elaborated in WCDMA networks. Then, the optimal rate allocation problem is formulated as a network utility maximization(NUM) model based on cross-layer design and end-to-end congestion control, aiming at exploring the impacts of wired networks and the characteristics of radio access networks(RANs) on rate allocation. Furthermore, a distributed algorithm is derived, which can effectively match load states between RANs and wired networks, followed by a detailed illustration of the practical implementations. Numerical results demonstrate a signifi cant performance improvement in the end-to-end throughput.
文摘This study measures visual attention to examine the impact of banner ads on reading and information processing on the Web. Using a 2 × 3 experimental design, 120 students were randomly assigned to read a series of either short or long articles on webpages presented with no banner ads, a static banner ad, or an animated banner ad. Visual attention was recorded by an eye-tracking device. Results from our study show that when there is too little information presented on a Webpage with no banner ads, the readers might become less attentive to the paper, while a long paper presented with too many visual stimuli may overload viewers＇ cognitive capacity. While these findings are generally consistent with past research that compared the impact of static ads against animated ads, the addition of a control condition and the varying of article length in our study extended previous research by revealing more complex visual processing and cognitive processes.
文摘Stress analysis of cylindrical grid-stiffened composite shells was conducted under transverse loading,pure bending,torsion and axial compression under clamped-free boundary condition.Electrical strain gauges were employed to measure the strains in transverse loading case to validate the finite element analysis which was conducted using ANSYS software.Good agreement was obtained between the two methods.It was observed that stiffening the composite shell with helical ribs decreased the average equivalent Von Mises stress on the shell.The reduction of the stress seemed to be higher in the intersection of two ribs.It was also seen that the stress reduction ratio was higher when the structure was under bending compared to torsion and axial compression.The reduction ratio was approximately 75% in pure bending in the intersection point of the ribs,while it was approximately 25% in torsion.Therefore,it is concluded that the presence of the ribs is more effective under bending.Failure analysis was done using Tsai-Wu criterion.The ribs were observed to result in maximum and minimum increase in the failure load of the structure under transverse bending and torsional loading,respectively.
基金China Medical Board(Grant No.17-270)National Natural Science Foundation of China(Grant No.81861138048 and 81973294)。
文摘In the present study,we aimed to assess the development of the antimicrobial stewardship(AMS)program in China’s tertiary hospitals to identify the potential challenges for the AMS program and provide references and benchmarks for strategic policymaking.A nationwide cross-sectional study was conducted online by sending questionnaires to tertiary hospitals under China Antimicrobial Resistance Surveillance System(CARSS).The questionnaire included 5 sections regarding structure,technical support,antimicrobial use management,antimicrobial use surveillance,and education.Descriptive statistics were used for data analysis.Of the 1044 tertiary hospitals under CARSS,13.4%(140)hospitals participated in the study.Among them,99.3%(139/140)set up the AMS program.The hospital president(82.1%,115/140)and medical service department(59.3%,83/140)were responsible for AMS outcomes in most hospitals.Structured antimicrobial formulary restriction management was adopted by 99.3%(139/140)hospitals.Infectious disease department,infection control department,and microbiological laboratories were established in 87.1%(122/140),99.3%(139/140)and 100%(140/140)hospitals,respectively.Up to 85.6%(124/140)hospitals applied clinical pathways,and 33.6%(47/140)hospitals implemented hospital-specific guidelines for infectious diseases.Outpatient prescription auditing,inpatient prescription auditing,and prophylactic antimicrobial prescription auditing of aseptic operation were performed in 99.3%(139/140),98.6%(138/140)and 95.7%(134/140)hospitals,respectively.Up to 97.1%(136/140)hospitals participated in antimicrobial use surveillance network,and 99.3%(139/140)hospitals established the specialized management of carbapenem and tigecycline.Staff education and public education were provided with various ways and frequencies in 100%(140/140)and 90.0%(126/140)hospitals,respectively.AMS programs in China’s tertiary hospitals were primarily headed by hospital presidents and involved collaboration among various disciplines and administrative departments.More efforts should be put to further promote and strengthen the development of hospital-specific guidelines and the establishment of a progress and outcome evaluation system.
