Online self-test wrapper for runtime-reconfigurable systems

Reconfigurable Systems-on-a-Chip (SoC) architectures consist of microprocessors and Field Programmable Gate Arrays (FPGAs). In order to implement runtime reconfigurable systems, these SoC devices combine the ease of programmability and the flexibility that FPGAs provide. One representative of these is the new Xilinx Zynq-7000 Extensible Processing Platform (EPP), which integrates a dual-core ARM Cortex-A9 based Processing System (PS) and Programmable Logic (PL) in a single device. After power on, the PS is booted and the PL can subsequently be configured and reconfigured by the PS. Recent FPGA technologies incorporate the dynamic Partial Reconfiguration (PR) feature. PR allows new functionality to be programmed online into specific regions of the FPGA while the performance and functionality of the remaining logic is preserved. This on-the-fly reconfiguration characteristic enables designers to time-multiplex portions of hardware dynamically, load functions into the FPGA on an as-needed basis. The configuration access port on the FPGA can be used to load the configuration data from memory to the reconfigurable block, which enables the user to reconfigure the FPGA online and test runtime systems. Manufactured in the advanced 28 nm technologies, the modern generations of FPGAs are increasingly prone to latent defects and aging-related failure mechanisms. To detect faults contained in the reconfigurable gate arrays, dedicated on and off-line test methods can be employed to test the device in the field. Adaptive systems require that the fault is detected and localized, so that the faulty logic unit will not be used in future reconfiguration steps. This thesis presents the development and evaluation of a self-test wrapper for the reconfigurable parts in such hybrid SoCs. It comprises the implementation of Test Configurations (TCs) of reconfigurable components as well as the generation and application of appropriate test stimuli and response analysis. The self-test wrapper is successfully implemented and is fully compatible with the AMBA protocols. The TC implementation is based on an existing Java framework for Xilinx Virtex-5 FPGA, and extended to the Zynq-7000 EPP family. These TCs are successfully redesigned to have a full logic coverage of FPGA structures. Furthermore, the array-based testing method is adopted and the tests can be applied to any part of the reconfigurable fabric. A complete software project has been developed and built to allow the reconfiguration process to be triggered by the ARM microprocessor. Functional test of the reconfigurable architecture, online self-test execution and retrieval of results are under the control of the embedded processor. Implementation results and analysis demonstrate that TCs are successfully synthesized and can be dynamically reconfigured into the area under test, and subsequent tests can be performed accordingly

Haemodynamic mechanism of formation and distribution of coronary atherosclerosis: A lesion-specific model

© IMechE 2020. Coronary arterial disease, as the most devastated cardiovascular disease, is caused by the atherosclerosis in the coronary arteries, which blocks the blood flow to the heart, resulting in the deficient supply of oxygen and nutrition to the heart, and eventually leading to heart failure. To date, haemodynamic mechanisms for atherosclerosis development are not fully understood although it is believed that the haemodynamic disturbance at the region of the arterial bifurcation, particular, bifurcation angle, plays an important role in the atherosclerosis development. In this study, two types of computational fluid dynamics models, lesion-specific and idealized models, combined with the computer tomography imaging techniques, are used to explore the mechanism of formation and distribution of the atherosclerosis around the bifurcation of left coronary artery and its association with the bifurcation angle. The lesion-specific model is used to characterize the effect of personalized features on the haemodynamic performance, while the idealized model is focusing on the effect of single factor, bifurcation angle, on the haemodynamic performance. The simulated results from both types of the models, combined with the clinical observation, revealed that the three key areas around the bifurcations are prone to formation of the atherosclerosis. Unlike the idealized models, lesion-specific modelling results did not show the significant correlation between the wall shear stress and bifurcation angle, although the mean value of the wall shear stress in smaller bifurcation angles (less than 90°) is higher than that with larger bifurcation angles (greater than 90°). In conclusion, lesion-specific computational fluid dynamics modelling is an efficient and convenient way to predict the haemodynamic performance around the bifurcation region, allowing the comprehensive information for the clinicians to predict the atherosclerosis development. The idealized models, which only focus on single parameter, may not provide the sufficient and reliable information for the clinical application. A novel multi-parameters modelling technique, therefore, is suggested to be developed in future, allowing the effects of many parameters on the haemodynamic performance to be evaluated

The design and impact of in-situ and operando thermal sensing for smart energy storage

Lithium-ion is increasingly the technology of choice for battery-powered systems. Current cell performance monitoring, which relies on measurements of full cell voltage and sporadic surface temperature, does not provide a reliable information on the true internal battery state. Here, we address this issue by transforming off the shelf cells into smart systems by embedding flexible distributed sensors for long-term in-situ and operando thermodynamic data collection. Our approach, which enables the monitoring of the true battery state, does not impact its performance. In particular, our results show that this unprecedented methodology can be used to optimise the performance and map the safety limits of lithium-ion cells. We find that the cell core temperature is consistently and significantly higher than the surface temperature, and reveal a breach of safety limits during a rapid discharge test. We also demonstrate an application of a current considerably higher than the manufacturers’ specification, enabling a significant decrease in charging time, without compromising the cell’s thermal stability. Consequently, this work on cell instrumentation methodology has the potential to facilitate significant advances in battery technology

Thyroid function and associated mood changes after COVID-19 vaccines in patients with Hashimoto thyroiditis

ContextSevere acute respiratory syndrome-coronavirus 2 (COVID-19) vaccines may incur changes in thyroid functions followed by mood changes, and patients with Hashimoto thyroiditis (HT) were suggested to bear a higher risk.ObjectivesWe primarily aim to find whether COVID-19 vaccination could induce potential subsequent thyroid function and mood changes. The secondary aim was to find inflammatory biomarkers associated with risk.MethodsThe retrospective, multi-center study recruited patients with HT receiving COVID-19–inactivated vaccines. C-reactive proteins (CRPs), thyroid-stimulating hormones (TSHs), and mood changes were studied before and after vaccination during a follow-up of a 6-month period. Independent association was investigated between incidence of mood state, thyroid functions, and inflammatory markers. Propensity score–matched comparisons between the vaccine and control groups were carried out to investigate the difference.ResultsFinal analysis included 2,765 patients with HT in the vaccine group and 1,288 patients in the control group. In the matched analysis, TSH increase and mood change incidence were both significantly higher in the vaccine group (11.9% versus 6.1% for TSH increase and 12.7% versus 8.4% for mood change incidence). An increase in CRP was associated with mood change (p< 0.01 by the Kaplan–Meier method) and severity (r = 0.75) after vaccination. Baseline CRP, TSH, and antibodies of thyroid peroxidase (anti-TPO) were found to predict incidence of mood changes.ConclusionCOVID-19 vaccination seemed to induce increased levels and incidence of TSH surge followed by mood changes in patients with HT. Higher levels of pre-vaccine serum TSH, CRP, and anti-TPO values were associated with higher incidence in the early post-vaccine phase

Experimental Verification of the Elastic Formula for the Aspirated Length of a Single Cell Considering the Size and Compressibility of Cell During Micropipette Aspiration

In this study, an aspiration system for elastic spheres was developed to verify the approximate elastic formula for the aspirated length of a single solid-like cell undergoing micropipette aspiration (MPA), which was obtained in our previous study by theoretical analysis and numerical simulation. Using this system, foam silicone rubber spheres with different diameters and mechanical properties were aspirated in a manner similar to the MPA of single cells. Comparisons between the approximate elastic formula and aspiration experiments of spheres indicated that the predictions of the formula agreed with the experimental results. Additionally, combined with the MPA data of rabbit chondrocytes, differences in terms of the elastic parameters derived from the half-space model, incompressible sphere model, and compressible sphere model were explored. The results demonstrated that the parameter ξ (ξ = R/a, where R is the radius of the cell and a is the inner radius of the micropipette) and Poisson’s ratio significantly influenced the determination of the elastic modulus and bulk modulus of the cell. This work developed for the first time an aspiration system of elastic spheres to study the elastic responses of the MPA of a single cell and provided new evidence supporting the use of the approximate elastic formula to determine cellular elastic parameters from the MPA data

Effectiveness of wildlife crossing structures on providing habitat connectivity for wild animals

Roads running through the middle of forests provide connectivity for humans, but are considered to be barriers to wildlife searching for food, shelter and mates. Wildlife crossing structures are now being designed and incorporated into numerous road constructions in many places in the world. However, the effectiveness of these wildlife crossing structures on providing wildlife connectivity remains uncertain. Studies from Banff National Park, Clark Fork River Valley, and Utah State clearly indicate factors affecting effectiveness of the crossing structures, which includes types of structures, dimensions, placement, noise levels, light level, vegetative cover, moisture, temperature, time, human disturbances, etc. All the factors make the evaluation of crossing structure effectiveness complex. While it is impractical to design a perfect structure that accommodate all species affected by roads, it may be possible to generate a comprehensive mitigation strategy integrating with all affecting factors and make the highways more permeable for wildlife in the future.Forestry, Faculty ofUnreviewedUndergraduat

Reconciliation with the Cats

This project investigates the cat eradication program on Christmas Island, Australia, through the lens of Landscape Architecture. By focusing on the unequal power relations between people and animals, Reconciliation with the Cats extends environmental issues into social issues and asks for a radical change in human society through landscape design and intervention. It opens opportunities to redefine the relationships between human, animals, and nature, and showcases an alternative future for Christmas Island.Applied Science, Faculty ofArchitecture and Landscape Architecture (SALA), School ofUnreviewedGraduat