6 research outputs found
Dynamic modeling and analysis of load sharing characteristics of wind turbine gearbox
A coupled dynamic model, which contains helical gears-shafts-bearings for a wind turbine gearbox transmission system, was built considering nonlinear factors of the time-varying mesh stiffness, the external varying load, and the dynamic transmission error at first. The model is confirmed to be right after comparing the theoretical data with the experimental load sharing values, and also it is found that the static load sharing is conservative to evaluate the non-equilibrium effect of a planetary gear system. Besides, the analyzing results of the influence of average error and amplitude error on the load sharing show that the load sharing could be decreased if the error goes up a little. Then, by means of treating the static tracing point as the dynamic initial values, we analyzed the initial positionâs influence on the load sharing of transmission system to provide a theoretical basis of load sharing control. Furthermore, we explored the influence of high-speed shaft position angle on the load sharing and the dynamic load factor of gears fixed on the parallel shafts. The results provide useful theoretical guidelines for the design of parallel shaft gear system in the wind turbines
Attack mitigation of hardware trojans for thermal sensing via micro-ring resonator in optical NoCs
As an emerging role in new-generation on-chip communication, optical networks-on-chip (ONoCs) provide ultra-high bandwidth, low latency and low power dissipation for data transfers. However, the thermo-optic effects of the photonic devices have a great impact on the operating performance and reliability of ONoCs, where the thermal-aware control with accurate measurements, e.g., thermal sensing, is typically applied to alleviate it. Besides, the temperature-sensitive ONoCs are prone to be attacked by the hardware Trojans (HTs) covertly embedded in the counterfeit integrated circuits (ICs) from the malicious third-party vendors, leading to performance degradation, denial-of-service (DoS), or even permanent damages. In this paper, we focus on the tampering and snooping attacks during the thermal sensing via micro-ring resonator (MR) in ONoCs. Based on the provided work flow and attack model, a new structure of the anti-HT module is proposed to verify and protect the obtained data from the thermal sensor for attacks in its optical sampling and electronic transmission processes. In addition, we present the detection scheme based on the spiking neural networks (SNNs) to implement an accurate classification of the network security statuses for further high-level control. Evaluation results indicate that, with less than 1% extra area of a tile, our approach can significantly enhance the hardware security of thermal sensing for ONoC with trivial costs of up to 8.73%, 5.32% and 6.14% in average latency, execution time and energy consumption, respectively.Ministry of Education (MOE)Nanyang Technological UniversityAccepted versionThis work is partially supported by the Ministry of Education, Singapore, under its Academic Research Fund Tier 2 (Grant No. MOE2019-T2-001-071) and Tier 1 (Grant No. MOE2019-T1-001-072), and Nanyang Technological University, Singapore, under its NAP (Grant No. M4082282) and SUG (Grant No. M4082087)
Mitigation of tampering attacks for MR-based thermal sensing in optical NoCs
As an emerging role in on-chip communication, the optical networks-on-chip (ONoCs) can provide ultra-high bandwidth, low latency and low power dissipation for the data transfer. However, the thermo-optic effects of the photonic devices have a great impact on the operating performance and reliability of ONoCs, where the thermal-aware control is used to alleviate it. Furthermore, the temperature-sensitive ONoCs are prone to be attacked by the hardware Trojans (HTs) covertly embedded in the integrated circuits (ICs) from the malicious third-party components, leading to performance degradation, denial of service (DoS), or even permanent damages. In this paper, we focus on the tampering attacks on optical sampling during the thermal sensing process in ONoCs. Corresponding approaches are proposed to mitigate the negative impacts from HT attacks. Evaluation results indicate that our approach can significantly enhance the hardware security of thermal sensing for ONoC with trivial overheads of up to 3.06% and 2.6% in average latency and energy consumption, respectively.Ministry of Education (MOE)Accepted versio
Fault-tolerant routing mechanism in 3D optical network-on-chip based on node reuse
The three-dimensional Network-on-Chips (3D NoCs) has become a mature multi-core interconnection architecture in recent years. However, the traditional electrical lines have very limited bandwidth and high energy consumption, making the photonic interconnection promising for future 3D Optical NoCs (ONoCs). Since existing solutions cannot well guarantee the fault-tolerant ability of 3D ONoCs, in this paper, we propose a reliable optical router (OR) structure which sacrifices less redundancy to obtain more restore paths. Moreover, by using our fault-tolerant routing algorithm, the restore path can be found inside the disabled OR under the deadlock-free condition, i.e., fault-node reuse. Experimental results show that the proposed approach outperforms the previous related works by maximum 81.1 percent and 33.0 percent on average for throughput performance under different synthetic and real traffic patterns. It can improve the system average optical signal to noise ratio (OSNR) performance by maximum 26.92 percent and 12.57 percent on average, and it can improve the average energy consumption performance by 0.3 percent to 15.2 percent under different topology types/sizes, failure rates, OR structures, and payload packet sizes
MiRâ223â3p alleviates trigeminal neuropathic pain in the male mouse by targeting MKNK2 and MAPK/ERK signaling
Abstract Background Trigeminal neuralgia (TN) is a neuropathic pain that occurs in branches of the trigeminal nerve. MicroRNAs (miRNAs) have been considered key mediators of neuropathic pain. This study was aimed to elucidate the pathophysiological function and mechanisms of miRâ223â3p in mouse models of TN. Methods Infraorbital nerve chronic constriction injury (CCIâION) was applied in male C57BL/6J mice to establish mouse models of TN. Pain responses were assessed utilizing Von Frey method. The expression of miRâ223â3p, MKNK2, and MAPK/ERK pathway protein in trigeminal ganglions (TGs) of CCIâION mice was measured using RTâqPCR and Western blotting. The concentrations of inflammatory cytokines were evaluated using Western blotting. The relationship between miRâ223â3p and MKNK2 was tested by a luciferase reporter assay. Results We found that miRâ223â3p was downregulated, while MKNK2 was upregulated in TGs of CCIâION mice. MiRâ223â3p overexpression by an intracerebroventricular injection of LvâmiRâ223â3p attenuated trigeminal neuropathic pain in CCIâION mice, as well as reduced the protein levels of proâinflammatory cytokines in TGs of CCIâION mice. MKNK2 was verified to be targeted by miRâ223â3p. Additionally, miRâ223â3p overexpression decreased the phosphorylation levels of ERK1/2, JNK, and p38 protein in TGs of CCIâION mice to inhibit MAPK/ERK signaling. Conclusions Overall, miRâ223â3p attenuates the development of TN by targeting MKNK2 to suppress MAPK/ERK signaling