49 research outputs found
Event-based Global Stabilization of Linear Systems via a Saturated Linear Controller
SUMMARY This paper investigates the problem of event-based linear control of systems subject to input saturation. First, for discrete-time systems with neutrally stable or double-integrator dynamics, novel event-triggered control algorithms with non-quadratic event-triggering conditions are proposed to achieve global stabilization. Compared with the quadratic event-triggering conditions, the non-quadratic ones can further reduce unnecessary control updates for the input-saturated systems. Furthermore, for continuous-time systems with neutrally stable or double-integrator dynamics, since that an inherent lower bound of the inter-event time does not exist for systems subject to input saturation, novel event-triggered control algorithms with an appropriately selected minimum inter-event time are proposed to achieve global stabilization. Finally, numerical examples are provided to illustrate the theoretical results
Wind power ramp detection algorithms based on slope point correction
Wind power ramp event refers to the large fluctuation of wind power in a short time interval, which will seriously affect the safe and stable operation of power grid system. In order to maintain the stable operation of power grid system, wind power ramp detection is extremely necessary. Therefore, how to improve the accuracy of wind power ramp detection is a problem worthy of study. In the existing wind power ramp detection algorithms, the accuracy of the ramp endpoint is not considered. Aiming at the problem of end-point accuracy in climbing section, this work proposes a wind power climbing detection algorithm RPCRD (ramp point correct climbing detection) based on ramp point correction, which considers the detection accuracy of wind power climbing point for the first time. In this algorithm, a merging method of climbing sections is proposed to solve the fracture problem, and a scoring mechanism for selecting climbing points is proposed to find the two extreme points that most conform to the climbing characteristics, and the climbing points at both ends of the climbing section of wind power are modified
Efficacy and safety of prophylactic intraoperative sac embolization in EVAR for abdominal aortic aneurysm: A meta-analysis
ObjectiveWe aimed to investigate the effectiveness and safety of prophylactic sac embolization during endovascular aneurysm repair (EVAR) in patients suffering from abdominal aortic aneurysms.MethodsWe performed a systematic literature search of PubMed, Web of Science, EMbase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP, Wanfang and China Biomedical Literature Database (CBM) to identify studies evaluating the outcomes of sac embolization vs. no embolization among patients who had received EVAR. The time limit of the search was from the establishing database to July 22, 2022. Outcome measures involved the type II endoleak rate, the other endoleak rate, the reintervention rate, mortality, and operation time. Fixed (no heterogeneity) or random effects models were constructed for each outcome. The outcomes are represented as the odds ratio (OR) with a 95% confidence interval (CI).ResultsAmong the 2,622 studies screened, 13 studies involving 747 participants were included in the review. The incidence of early-term type II endoleak (OR = 0.2, 95% CI (0.13,0.31), P < 0.00001), mid-term type II endoleak (OR = 0.23, 95% CI (0.15,0.37), P < 0.00001), late-term type II endoleak (OR = 0.27, 95% CI (0.16,0.46), P < 0.00001) and reintervention (OR = 0.50, 95% CI (0.37,0.78), P = 0.002) within the sac embolization group were significantly lower than those in the non-embolization group. No significant differences were observed between the two groups were found for the other endoleak rates (OR = 0.67, 95% CI (0.34,1.32), P = 0.25), mortality (OR = 0.64, 95% CI (0.25,1.66), P = 0.36) and operation time operation (MD = 5.76, 95% CI (-8.30,19.83), P = 0.42).ConclusionsEVAR combined with sac embolization effectively reduces the incidence of type II endoleak and the reintervention rate without enhancing the operation time. Therefore, more high-quality studies are still needed for validation due to the limited amount and quality of included literature.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022365648
Biodegradable Thermosensitive Hydrogel for SAHA and DDP Delivery: Therapeutic Effects on Oral Squamous Cell Carcinoma Xenografts
Background: OSCC is one of the most common malignancies and numerous clinical agents currently applied in combinative chemotherapy. Here we reported a novel therapeutic strategy, SAHA and DDP-loaded PECE (SAHA-DDP/PECE), can improve the therapeutic effects of intratumorally chemotherapy on OSCC cell xenografts. Objective/Purpose: The objective of this study was to evaluate the therapeutic efficacy of the SAHA-DDP/PECE in situ controlled drug delivery system on OSCC cell xenografts. Methods: A biodegradable and thermosensitive hydrogel was successfully developed to load SAHA and DDP. Tumorbeared mice were intratumorally administered with SAHA-DDP/PECE at 50 mg/kg (SAHA) +2 mg/kg (DDP) in 100 ul PECE hydrogel every two weeks, SAHA-DDP at 50 mg/kg(SAHA) +2 mg/kg(DDP) in NS, 2 mg/kg DDP solution, 50 mg/kg SAHA solution, equal volume of PECE hydrogel, or equal volume of NS on the same schedule, respectively. The antineoplastic actions of SAHA and DDP alone and in combination were evaluated using the determination of tumor volume, immunohistochemistry, western blot, and TUNEL analysis. Results: The hydrogel system was a free-flowing sol at 10uC, become gel at body temperature, and could sustain more than 14 days in situ. SAHA-DDP/PECE was subsequently injected into tumor OSCC tumor-beared mice. The results demonstrated that such a strategy as this allows the carrier system to show a sustained release of SAHA and DDP in vivo, and coul
Enabling real-life deployment of piggyback-VLC via light emission composition
Whereas the increasing popularity of both commercial light-emitting diode (LED) lighting and mobile devices certainly creates opportunity for real-life deployment of visible light communication (VLC) systems, reaching the high throughput promised by lab experiments still faces major obstacles. In particular, lacking the sophisticated hardware and software support under experimental conditions, real-life systems are challenged in many aspects, especially low signal-to-noise ratio, low operation frequency, uncontrollable LED nonlinearity, and illumination requirements. Nonetheless, deployments tapping commercial infrastructure are critical to gain market penetration for VLC-enabled wireless applications, so boosting the performance of these real-life systems becomes imperative. In this article, we consider the multiple LED chips and/or light sources nature of indoor commercial lighting infrastructure, and propose a spatial modulation that composes the cooperative light emissions (transmissions) from multiple LEDs. In addition to gaining a higher spectral efficiency, this scheme utilizes the multiple-LED nature of commercial lighting to overcome LED nonlinearity with a novel yet simplified hardware construction. We present two typical designs adopting this special modulation under different infrastructural constraints, and provide an introduction on its potential contribution to the standardization of VLC. Finally, we discuss potential extensions to further improve performance.Ministry of Education (MOE)This work was supported in part by National Natural Science Foundation of China under Grant 61902267 and Grant 61901065, in part by the Fundamental Research Funds for the Central Universities under Grant YJ201868, in part by the Sichuan Science and Technology Program under Grant 19ZDYF0045 and Grant 19CXTD0005, in part by the the AcRF Tier 2 Grant MOE2016-T2-2- 022, and in part by the DSAIR Center at NTU
Dividend regulation and cost stickiness: evidence from a quasi-natural experiment
This paper aims to examine the effect of dividend regulation on cost stickiness (i.e. the asymmetric change in firm expense between sales increase and sales decrease) and explore the underlying mechanism.
Based on the quasi-natural experiment of the Guideline for Dividend Policy of Listed Companies issued by the Shanghai Stock Exchange (SSE) in 2013, the authors employ a difference-in-difference model to investigate the impact of dividend regulation on cost stickiness.
The authors find that the cost stickiness of treatment group firms has decreased significantly when compared with control group firms after the dividend regulation. Moreover, this effect is more pronounced among firms in lower marketization regions, in lower competition industries and those with less analyst coverage and lower cash flow levels. Further analyses show that dividend regulation reduces the cost stickiness of firms by mitigating agency problems. Finally, the conclusion holds after several robust tests, including controlling for firm fixed effect, propensity score matching (PSM), placebo test and reconstruction of expense variable.
This paper confirms that dividend regulation serves an important role in corporate governance, which reduces firms' agency costs and thereby decreases cost stickiness. The conclusions shed light on the dividend policies of listed companies and capital market regulation in the future
Effects of LAB Inoculants on the Fermentation Quality, Chemical Composition, and Bacterial Community of Oat Silage on the Qinghai-Tibetan Plateau
Lactic acid bacteria (LAB) have been proposed for the control of undesirable fermentation and, subsequently, aerobic deterioration due to their ability to produce antimicrobial metabolites in silage mass. To investigate the effect of specific LAB on the silage fermentation characteristics and bacterial community composition of oat in cold regions, silages were treated without (control) or with three LAB strains (LB, Lentilactobacillus buchneri; nLP, low temperature tolerant Lactiplantibacillus plantarum; pLP, phenyllactic acid-producing Lactiplantibacillus plantarum), and then stored at ambient temperature (−2.63 ± 5.47–14.29 ± 5.48 °C) for 30, 60, and 90 days. Compared with control, inoculation of LAB decreased the final pH value, butyric acid content, ammonia-N of total N and dry matter loss of silage. Treatments with nLP and pLP increased (p < 0.05) lactic acid content, whereas LB increased (p < 0.05) acetic acid content of silage. Lactiplantibacillus and Leuconostoc dominated in the silages with relative abundance of 68.29–96.63%. A prolonged storage period enhanced the growth of Leuconostoc in pLP-treated silage. In addition, pLP increased (p < 0.05) the aerobic stability of silage as compared with nLP. In conclusion, inoculation of LAB improved silage fermentation and/or delayed aerobic deterioration by shifting bacterial community composition during ensiling. Phenyllactic acid-producing Lactiplantibacillusplantarum as an inoculant exhibited potential for high quality silage production
MMRDF: An improved multitask multi‐modal rumor detection framework
Abstract As images are attractive and contained in plenty of posts, some studies show that combining multimodal information helps to represent posts effectively, while these approaches (1) simply concatenated unimodal features without considering inter‐modality relations, which failed to improve the prediction performance and generalization ability; (2) lacked careful consideration of the social network data composition structure, assuming that social network data was composed of image‐text pairs, cannot process the data composed of multi‐images, and cannot operate when one of the modalities is missing. To address these issues, a novel framework named multitask multimodal rumor detection framework (MMRDF) is proposed, comprising three sub‐networks, which is available to generate joint multimodal representation through merging different levels of features in multi‐modalities and can deal with all types of tweets (pure text, pure image, image‐text pair and text with multi‐images) flexibly. Since the framework does not take the data that causes extra time delay as inputs, such as propagation structures and response content, it can be applied as soon as the tweets are posted up and decrease the time delays of rumor debunking. Experiments on two real‐world datasets demonstrate the framework significantly outperforms the state‐of‐the‐art by the accuracy of 6.5% and 7.6%