Security and health: Biopolitical health surveillance in China’s digital response to COVID-19

Why is health a security issue now? An emerging paradigm that links epidemics and security concerns has influenced how we think about health and the preparedness of health surveillance. As the ongoing COVID-19 pandemic has swept the world with its tremendous threats to public health and societies, innovative digital health surveillance technologies have been (and continue to be) developed for pandemic surveillance. With a special focus on China’s Health Code system and its implementation in Wuhan since the Wuhan lockdown, this thesis aims to examine the surveillance dynamics of such technological artefacts. In doing so, this thesis applies institutional ethnography (IE) to illustrate how the ruling relations embedded in such assemblages coordinate and organize citizens’ everyday lives. The primary findings of this thesis suggest that Health Code as a health security practice is a flexible and dynamic surveillance assemblage embedded with political classifications and decisions to define and mediate risk in everyday settings, located in a larger network of power relations. The insecurities and anxieties brought by the normalized use of Health Code exacerbate the fear of being classified as sick, as the threat of illness leads people to embrace the current situation and cooperate with the existing surveillance system through the rationalization of collective norms and the valorization and stabilization of data-driven knowledge

H∞ filter for flexure deformation and lever arm effect compensation in M/S INS integration

ABSTRACTOn ship, especially on large ship, the flexure deformation between Master (M)/Slave (S) Inertial Navigation System (INS) is a key factor which determines the accuracy of the integrated system of M/S INS. In engineering this flexure deformation will be increased with the added ship size. In the M/S INS integrated system, the attitude error between MINS and SINS cannot really reflect the misalignment angle change of SINS due to the flexure deformation. At the same time, the flexure deformation will bring the change of the lever arm size, which further induces the uncertainty of lever arm velocity, resulting in the velocity matching error. To solve this problem, a H∞ algorithm is proposed, in which the attitude and velocity matching error caused by deformation is considered as measurement noise with limited energy, and measurement noise will be restrained by the robustness of H∞ filter. Based on the classical “attitude plus velocity” matching method, the progress of M/S INS information fusion is simulated and compared by using three kinds of schemes, which are known and unknown flexure deformation with standard Kalman filter, and unknown flexure deformation with H∞ filter, respectively. Simulation results indicate that H∞ filter can effectively improve the accuracy of information fusion when flexure deformation is unknown but non-ignorable

Cortical Neural Stem Cell Lineage Progression Is Regulated by Extrinsic Signaling Molecule Sonic Hedgehog.

Neural stem cells (NSCs) in the prenatal neocortex progressively generate different subtypes of glutamatergic projection neurons. Following that, NSCs have a major switch in their progenitor properties and produce γ-aminobutyric acid (GABAergic) interneurons for the olfactory bulb (OB), cortical oligodendrocytes, and astrocytes. Herein, we provide evidence for the molecular mechanism that underlies this switch in the state of neocortical NSCs. We show that, at around E16.5, mouse neocortical NSCs start to generate GSX2-expressing (GSX2+) intermediate progenitor cells (IPCs). In vivo lineage-tracing study revealed that GSX2+ IPC population gives rise not only to OB interneurons but also to cortical oligodendrocytes and astrocytes, suggesting that they are a tri-potential population. We demonstrated that Sonic hedgehog signaling is both necessary and sufficient for the generation of GSX2+ IPCs by reducing GLI3R protein levels. Using single-cell RNA sequencing, we identify the transcriptional profile of GSX2+ IPCs and the process of the lineage switch of cortical NSCs

Adaptive EWMA Method Based on Abnormal Network Traffic for LDoS Attacks

The low-rate denial of service (LDoS) attacks reduce network services capabilities by periodically sending high intensity pulse data flows. For their concealed performance, it is more difficult for traditional DoS detection methods to detect LDoS attacks; at the same time the accuracy of the current detection methods for LDoS attacks is relatively low. As the fact that LDoS attacks led to abnormal distribution of the ACK traffic, LDoS attacks can be detected by analyzing the distribution characteristics of ACK traffic. Then traditional EWMA algorithm which can smooth the accidental error while being the same as the exceptional mutation may cause some misjudgment; therefore a new LDoS detection method based on adaptive EWMA (AEWMA) algorithm is proposed. The AEWMA algorithm which uses an adaptive weighting function instead of the constant weighting of EWMA algorithm can smooth the accidental error and retain the exceptional mutation. So AEWMA method is more beneficial than EWMA method for analyzing and measuring the abnormal distribution of ACK traffic. The NS2 simulations show that AEWMA method can detect LDoS attacks effectively and has a low false negative rate and a false positive rate. Based on DARPA99 datasets, experiment results show that AEWMA method is more efficient than EWMA method

Flexible graphene-coated carbon fiber veil/polydimethylsiloxane mats as electrothermal materials with rapid responsiveness

Flexible electrothermal mats with rapid responsiveness were prepared by spray-coating of graphene nanoplates (GNP) acetone dispersion on carbon fiber veil and following curing of polydimethylsiloxane (PDMS) on the mats. Morphological feature, electrical property, and electrothermal behavior of the mats with different area density from 55 to 20 g m−2 were investigated. Scanning electronic microscope (SEM) confirmed that pristine graphene nanoplates were uniformly deposited on the surface of carbon fiber resulting in volume resistance decreased substantially. Compared with the carbon fiber veil without coated GNP, the electric heating behavior of graphene-coated carbon fiber/PDMS mats were improved largely, such as the stead-state maximum temperature reached 297 °C, the maximum heating rate reached 5°Cs−1 tested by an infrared camera, the maximum power density reached 11.11 kW m−2. The respond time from room temperature 25 °C–200 °C was only 40 s tested by infrared thermal image. Even under high twisting/bending state or continuous stepwise voltage changes, the graphene-coated carbon fiber/PDMS mats retained stable electrical heating performance in aspects of temperature responsiveness and steady-state maximum temperature

Subtle features of delamination in cross-ply laminates due to low speed impact

In cross-ply laminates, the shape of delamination areas, which form due to low velocity impact, have two subtle features, which have been observed consistently in numerous experiments. Those are the pointed delamination tips and the intact zone between the lobes of delamination. However, there have not been any account available in the literature how they can be consistently captured through numerical modelling, and hence these features in published modelling results were often absent. It is the objective of this paper to identify the underlying modelling considerations so that these features can be captured with confidence. A key and unique reason has been identified in each case. Namely, inclusion of intra-laminar damage allows to reproduce the pointed delamination tips, while the gap between the lobes of delamination can be captured by models with sufficiently refined mesh, where friction between the laminas is taken into account. The capability of capturing these subtle features helps to raise the level of fidelity on the simulation of delamination due to impact

Study on toughness improvement of a rosin-sourced epoxy matrix composite for green aerospace application

A high temperature epoxy resin was formulated by using a rosin-sourced anhydride-type curing agent, i.e., maleopimaric acid (RAM), and a two-component epoxy consisting of an E51-type epoxy and a solid phenolic epoxy to form a bio-sourced green matrix resin. The glass transition temperature of the final resin was 238◦C Carbon fiber composite prepreg and was manufactured and laminated into composite specimens. Interleaving Toughening Technology (ITT) was applied to the laminates by using Polyamide interleaf veils. The interlaminar fracture toughness and compression after impact (CAI) strength were investigated and showed that the opening Mode I interlaminar fracture toughness GIC and the Mode II interlaminar fracture toughness GIIC of the specimens with interleaves were significantly improved from 227.51 J/m2 to 509.22 J/m2 and 1064.3 J/m2 to 1510.8 J/m2, respectively. Correspondingly, the drop-weight impact test shows that the interleaves reduced the impact damage area from 20.9% to 11.3% of the total area, and the CAI residual strength was increased from 144 MPa to 191 MPa. Meanwhile, mechanical tests showed that the in-plane properties of the interleaved laminates were slightly reduced due to carbon fiber volume fraction reduction. In conclusion, the high glass transition temperature, fracture toughness and CAI behaviour make the green resin matrix composite a potential candidate for aerospace applications

Outlook on ecologically improved composites for aviation interior and secondary structures

Today, mainly man-made materials such as carbon and glass fibres are used to produce composite parts in aviation. Renewable materials such as natural fibres or bio-sourced resin systems have not found their way into aviation, yet. The project ECO-COMPASS aims to evaluate the potential applications of ecologically improved composite materials in the aviation sector in an international collaboration of Chinese and European partners. Natural fibres such as flax and ramie will be used for different types of reinforcements and sandwich cores. Furthermore, the bio-based epoxy resins to substitute bisphenol-A based epoxy resins in secondary structures are under investigation. Adapted material protection technologies to reduce environmental influence and to improve fire resistance are needed to fulfil the demanding safety requirements in aviation. Modelling and simulation of chosen eco-composites aims for an optimized use of materials while a life cycle assessment aims to prove the ecological advantages compared to synthetic state-of-the-art materials. In this paper, the status of selected ecologically improved materials will be presented with an outlook for potential application in interior and secondary structures