Research on trajectory tracking control for wet clutch engagement based on SMC

AbstractTo improve tracking control quality of the clutch actuator during the wet clutch engagement, models of the clutch actuator were established firstly, including the control cylinder model, flow equilibrium equation and pressure control model. Secondly, taking the clutch output speed as tracking target, the state space equation of the tracking control system was set up and the sliding mode controller (SMC) was designed. Finally, a simulation test was performed. The results show that a higher tracking accuracy as well as a better performance to resist disturbance can be achieved with the proposed sliding control method, compared to PI control. It was also shown that the exponent approaching sliding mode control can produce smaller chattering compared with the constant rate approaching sliding mode control

True-data Testbed for 5G/B5G Intelligent Network

Future beyond fifth-generation (B5G) and sixth-generation (6G) mobile communications will shift from facilitating interpersonal communications to supporting Internet of Everything (IoE), where intelligent communications with full integration of big data and artificial intelligence (AI) will play an important role in improving network efficiency and providing high-quality service. As a rapid evolving paradigm, the AI-empowered mobile communications demand large amounts of data acquired from real network environment for systematic test and verification. Hence, we build the world's first true-data testbed for 5G/B5G intelligent network (TTIN), which comprises 5G/B5G on-site experimental networks, data acquisition & data warehouse, and AI engine & network optimization. In the TTIN, true network data acquisition, storage, standardization, and analysis are available, which enable system-level online verification of B5G/6G-orientated key technologies and support data-driven network optimization through the closed-loop control mechanism. This paper elaborates on the system architecture and module design of TTIN. Detailed technical specifications and some of the established use cases are also showcased.Comment: 12 pages, 10 figure

Synthesis, Biological Evaluation of Fluorescent 23-Hydroxybetulinic Acid Probes, and Their Cellular Localization Studies

© 2018 American Chemical Society. 23-Hydroxybetulinic acid (23-HBA) is a complex lupane triterpenoid, which has attracted increasing attention as an anticancer agent. However, its detailed mechanism of anticancer action remains elusive so far. To reveal its anticancer mode of action, a series of fluorescent 23-HBA derivatives conjugated with coumarin dyes were designed, synthesized, and evaluated for their antiproliferative activities. Subcellular localization and uptake profile studies of representative fluorescent 23-HBA probe 26c were performed in B16F10 cells, and the results suggested that probe 26c was rapidly taken up into B10F10 cells in a dose-dependent manner and mitochondrion was the main site of its accumulation. Further mode of action studies implied that the mitochondrial pathway was involved in 23-HBA-mediated apoptosis. Together, our results provided new clues for revealing the molecular mechanism of natural product 23-HBA for its further development into an antitumor agent

6,7-seco-ent-kauranoids derived from oridonin as potential anticancer agents

Structurally unique 6,7-seco-ent-kaurenes, which are widely distributed in the genus Isodon, have attracted considerable attention because of their antitumor activities. Previously, a convenient conversion of commercially available oridonin (1) to 6,7-seco-ent-kaurenes was developed. Herein, several novel spiro-lactone-type ent-kaurene derivatives bearing various substituents at the C-1 and C-14 positions were further designed and synthesized from the natural product oridonin. Moreover, a number of seven-membered C-ring-expanded 6,7-seco-ent-kaurenes were also identified for the first time. It was observed that most of the spiro-lactone-type ent-kaurenes tested markedly inhibited the proliferation of cancer cells, with an IC50 value as low as 0.55 μM. An investigation on its mechanism of action showed that the representative compound 7b affected the cell cycle and induced apoptosis at a low micromolar level in MCF-7 human breast cancer cells. Furthermore, compound 7b inhibited liver tumor growth in an in vivo mouse model and exhibited no observable toxic effects. Collectively, the results warrant further preclinical investigations of these spiro-lactone-type ent-kaurenes as potential novel anticancer agents

Discovery of novel antitumor nitric oxide-donating b-elemene hybrids through inhibiting the PI3K/Akt pathway

A series of novel furoxan-based NO-donating b-elemene hybrids were designed and synthesized to improve the anticancer efficacy of natural b-elemene. The bioassay results indicated that all of the target compounds exhibited significantly improved antiproliferative activities against three cancer cell lines (SGC-7901, HeLa and U87) compared to parent compound b-elemene. Interestingly, these compounds displayed excellent sensitivity to U87 cells with IC50 values ranging from 173 to 2 nM. Moreover, most compounds produced high levels of NO in vitro, and the antitumor activity of 11a in U87 cells was markedly attenuated by an NO scavenger (hemoglobin or carboxy-PTIO). Further mechanism studies revealed that 11a caused the G2 phase arrest of the cell cycle and induced apoptosis of U87 cells by preventing the activation of the PI3K/Akt pathway. Moreover, 11a significantly suppressed the tumor growth in H22 liver cancer xenograft mouse model with a tumor inhibitory ratio (TIR) of 64.8%, which was superior to that of b-elemene (TIR, 49.6%) at the same dose of 60 mg/kg. Together, the remarkable biological profiles of these novel NO-donating b-elemene derivatives may make them promising candidates for the intervention of human cancers

Design, synthesis, and biological evaluation of NAD(P)H: quinone oxidoreductase (NQO1)-targeted oridonin prodrugs possessing indolequinone moiety for hypoxia-selective activation

The enzyme NQO1 is a potential target for selective cancer therapy due to its overexpression in certain hypoxic tumors. A series of prodrugs possessing a variety of cytotoxic diterpenoids (oridonin and its analogues) as the leaving groups activated by NQO1 were synthesized by functionalization of 3-(hydroxymethyl)indolequinone, which is a good substrate of NQO1. The target compounds (29a-m) exhibited relatively higher antiproliferative activities against NQO1-rich human colon carcinoma cells (HT-29) and human lung carcinoma (A549) cells (IC50 ¼ 0.263e2.904 mM), while NQO1-defficient lung adenosquamous carcinoma cells (H596) were less sensitive to these compounds, among which, compound 29h exhibited the most potent antiproliferative activity against both A549 and HT-29 cells, with IC50 values of 0.386 and 0.263 mM, respectively. Further HPLC and docking studies demonstrated that 29h is a good substrate of NQO1. Moreover, the investigation of anticancer mechanism showed that the representative compound 29h affected cell cycle and induced NQO1 dependent apoptosis through an oxidative stress triggered mitochondria-related pathway in A549 cells. Besides, the antitumor activity of 29h was also verified in a liver cancer xenograft mouse model. Biological evaluation of these compounds concludes that there is a strong correlation between NQO1 enzyme and induction of cancer cell death. Thus, this suggests that some of the target compounds activated by NQO1 are novel prodrug candidates potential for selective anticancer therapy

6G Network AI Architecture for Everyone-Centric Customized Services

Mobile communication standards were developed for enhancing transmission and network performance by using more radio resources and improving spectrum and energy efficiency. How to effectively address diverse user requirements and guarantee everyone's Quality of Experience (QoE) remains an open problem. The Sixth Generation (6G) mobile systems will solve this problem by utilizing heterogenous network resources and pervasive intelligence to support everyone-centric customized services anywhere and anytime. In this article, we first coin the concept of Service Requirement Zone (SRZ) on the user side to characterize and visualize the integrated service requirements and preferences of specific tasks of individual users. On the system side, we further introduce the concept of User Satisfaction Ratio (USR) to evaluate the system's overall service ability of satisfying a variety of tasks with different SRZs. Then, we propose a network Artificial Intelligence (AI) architecture with integrated network resources and pervasive AI capabilities for supporting customized services with guaranteed QoEs. Finally, extensive simulations show that the proposed network AI architecture can consistently offer a higher USR performance than the cloud AI and edge AI architectures with respect to different task scheduling algorithms, random service requirements, and dynamic network conditions

A Study on Correlation of Traffic Accident Tendency with Driver Characters Using In-Depth Traffic Accident Data

Traffic accidents are often related to the driver’s driving behavior, which is mainly decided by his or her characters. In order to explore the correlation of traffic accident risk with driver characters, the age, driving experience, and driving style were statistically analyzed based on the China In-Depth Accident Study (CIDAS) database. Taking the number of casualties in the accident as evaluation indicators, the grey cluster analysis was used to classify the drivers into four accident risk ranks: low, medium to low, medium to high, and high. The results show that drivers aged 18–30 years are more likely to induce accidents; drivers with 6–10 years of driving experience have the highest risk to accidents, followed by drivers with 4-5 years of driving experience; and the driving style is also highly correlated with accident risk tendency

Internal Biomechanical Study of a 70-Year-Old Female Human Lumbar Bi-Segment Finite Element Model and Comparison with a Middle-Aged Male Model

The main purpose of this article is to study the biomechanics of spine tissue in elderly female. In this study, the L3-L5 lumbar bi-segmental finite element model for elderly female was obtained from the Advanced Human Modeling Laboratory of the Bioengineering Center at Wayne State University. The effects of flexion and extension on bone geometry, distribution of ligament fibers, location of nucleus, and changes in intervertebral disc height were studied by comparing the results obtained before and after the update of older female and middle-aged male models. For the purpose of comparing the calculated range of motion (ROM) with the experimental data, additional calculations for axial rotation and lateral bending were performed. The study found that the parameters of the model affected the deformation of the disc herniation, ligament and intervertebral disc, and the axial force carrying capacity of the model. The three predicted ROMs are usually similar to the experimental results. Only the older female model has a slightly larger ROM. Therefore, older women are more vulnerable to lumbar spine injuries than men