Distributed Evaluation and Convergence of Self-Appraisals in Social Networks

We consider in this paper a networked system of opinion dynamics in continuous time, where the agents are able to evaluate their self-appraisals in a distributed way. In the model we formulate, the underlying network topology is described by a rooted digraph. For each ordered pair of agents $(i,j)$, we assign a function of self-appraisal to agent $i$, which measures the level of importance of agent $i$ to agent $j$. Thus, by communicating only with her neighbors, each agent is able to calculate the difference between her level of importance to others and others' level of importance to her. The dynamical system of self-appraisals is then designed to drive these differences to zero. We show that for almost all initial conditions, the trajectory generated by this dynamical system asymptotically converges to an equilibrium point which is exponentially stable

Failure mechanism of single-layer saddle-curve reticulated shells subjected to erathquakes

p. 345-354In order to have a good understanding of the failure mechanism of single-layer saddle-curve reticulated shells under earthquake motion, dynamic failure mode of single-layer saddlecurve reticulated shells under earthquake motion is discussed with accumulation of material damage introduced to analyze the failure of these shells under dynamic actions. Based on the comprehension of the mechanical behaviours and structural full-range characteristic responses in an example, dynamic strength failure due to excessive development of plastic deformation is a mainly failure mode for single-layer saddle-curve reticulated shells subjected to earthquakes. Then, a method is proposed for determination of failure state. The relationships between structural responses under ultimate load and different structural parameters are investigated through simulation.Zhi, X.; Fan, F.; Shen, S.; Fan, Q. (2009). Failure mechanism of single-layer saddle-curve reticulated shells subjected to erathquakes. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/652

Workplace violence and its aftermath in China's health sector: implications from a cross-sectional survey across three tiers of the health system.

OBJECTIVES: To determine the prevalence of physical violence and threats against health workers and the aftermath in tertiary, secondary and primary care facilities in China. DESIGN: A cross-sectional questionnaire study. SETTING: 5 tertiary hospitals, 8 secondary hospitals and 32 primary care facilities located in both urban and rural areas of Zhejiang Province, China, were chosen as the study sites. PARTICIPANTS: A total of 4862 health workers who have contact with patients completed a survey from July 2016 to July 2017. OUTCOME MEASURES: The prevalence of physical violence, threats and Yi Nao, specific forms of physical violence and their aftermath were measured by a self-designed and verified questionnaire. Multivariable logistic regression models were used to examine the association between perceived organisational encouragement of reporting workplace violence (WPV) and physical violence, threats and Yi Nao after controlling for age, sex, level of facility, professional ranking and type of health worker. RESULTS: Among all respondents, 224 (4.6%) were physically attacked and 848 (17.4%) experienced threats in the past year. Respondents in secondary hospitals were more likely to experience physical violence (AOR=3.29, 95% CI 2.21 to 4.89), threats (AOR=1.61, 95% CI 1.32 to 1.98) and Yi Nao (AOR=2.47, 95% CI 2.10 to 2.91), compared with primary care providers. Lack of organisational policies to report WPV was associated with higher likelihood of physical violence (AOR=3.64, 95% CI 2.57 to 5.18) and threats (AOR=2.21, 95% CI 1.76 to 2.78). Among physical violence cases, only 29.1% reported the attack to police mainly because most felt it useless to do so (58.8%). Only 25.7% were investigated and 72.4% of attackers received no punishment. Of all those attacked or threatened, 59.4% wanted to quit current post and 76.0% were fearful of dealing with urgent or severe cases. CONCLUSIONS: Proper management of the aftermath of violence against health workers is inadequate. Formal guidelines for reporting and managing WPV are urgently needed

Corrigendum to: The TianQin project: current progress on science and technology

In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article

Influence of the Roofing System on the Seismic Performance of Single-Layer Spherical Reticulated Shell Structures

The seismic performance of a single-layer spherical reticulated shell is the key problem to be solved in the design and analysis of this structure. In previous studies, the influences of roofing systems on the seismic performance of shells were usually ignored, resulting in large discrepancies between the results of analyses and the actual stress states of shells. In this paper, the finite element analysis method is applied to a shell with a roofing system, and the applicability of the method is proven by static loading experiments. The influences of roofing systems on the seismic performance of shells are obtained from seismic response curves, the proportions and distributions of plastic members and the failure behaviours of the shells during strong earthquakes. The mechanism of the influence of the roofing system on the seismic response of a shell is revealed by analysing the damage of purlin joints and the energy consumption of the components of the shell. The relationships that describe the influence of different parameters of reticulated shells and roofing systems on the seismic response of the shells are studied, and the results show that the roofing system can greatly change the seismic response and failure of a shell under strong earthquake conditions

Quasi-static compressive behaviour of 3D-printed origami-inspired cellular structure: experimental, numerical and theoretical studies

This paper proposed a novel periodic cellular structure by introducing re-entrant hexagon-shaped honeycombs and Miura origami geometry. The large-scale multi-layer metallic specimens were manufactured by a selective laser melting (SLM) system and tested for the first time. The compression deformation and energy absorption characteristics under quasi-static load were investigated thoroughly, considering three loading directions and various geometric parameters. The results show that this novel structure has balanced mechanical properties in the three loading directions. Among them, the z-direction is the best bearing direction. Moreover, this structure exhibits an obvious three-dimensional negative Poisson's ratio effect during the compression process. Besides the experimental study, the numerical investigation base on ANSYS/LS-DYNA was carried out to provide an accurate and effective simulation method. Predictive formulas for the critical energy absorption indexes were derived by theoretical analysis based on the rigid folding assumption, validated to be well-matched with the experimental results

DSM Formula for Local-Global Interaction Buckling of Cold-Formed Stainless Steel I-Beams

The paper presents a set of Direct Strength Method (DSM) formulae for cold-formed stainless steel I-section beams. On basis of a carefully calibrated FE model for stainless steel open-section beams featuring local-global interaction buckling, an extensive database was first established. The existing DSM formula of the best prediction performance was commented on for its drawbacks. For improved strength prediction, a traditional-form DSM formula was proposed first, and novel two-phase DSM formulae were derived on basis of a deep insight into the varying trend of the member strengths. The two-phase DSM formulae were found to be very powerful predictors yielding more accurate strength predictions over the whole range of slenderness and avoiding undue conservatism for intermediate and short members. A considerable boost in design strength by up to 39% can be achieved with the two-phase DSM formula. The DSM curves were developed with a due reliability level to fit into the current design codes