Shifting from a thermal-constrained to water-constrained ecosystem over the Tibetan Plateau

IntroductionUnderstanding the seasonality of vegetation growth is important for maintaining sustainable development of grassland livestock systems over the Tibetan Plateau (TP). Current knowledge of changes in the seasonality of TP grasslands is restricted to spring and autumn phenology, with little known about the date of peak vegetation growth, the most relevant quantity for grassland productivity.MethodsWe investigate the shifts of the date of peak vegetation growth and its climatic controls for the alpine grasslands over the TP during 2001–2020 using a framework based on the law of minimum, which is based on the assumption that peak vegetation growth would be consistent with the peak timing of the most limiting climatic resource.ResultsThe date of peak vegetation growth over the TP advanced by 0.81 days decade-1 during 2001–2020. This spring-ward shift mainly occurs in the semi-humid eastern TP, where the peak growth date tracks the advancing peak precipitation, and shifted towards the timing of peak temperature. The advancing peak growth over the eastern TP significantly stimulated the ecosystem production by 1.99 gCm-2 year-1 day-1 during 2001–2020, while this positive effect weakened from 3.02 gCm-2 year-1 day-1 during 2000s to 1.25 gCm-2 year-1 day-1 during 2010s.DiscussionOur results highlighted the importance of water availability in vegetation growth over the TP, and indicated that the TP grassland is moving towards a tipping point of transition from thermal-constrained to water-constrained ecosystem under the rapid warming climate

Stereoscopic Omnidirectional Image Quality Assessment Based on Predictive Coding Theory

Objective quality assessment of stereoscopic omnidirectional images is a challenging problem since it is influenced by multiple aspects such as projection deformation, field of view (FoV) range, binocular vision, visual comfort, etc. Existing studies show that classic 2D or 3D image quality assessment (IQA) metrics are not able to perform well for stereoscopic omnidirectional images. However, very few research works have focused on evaluating the perceptual visual quality of omnidirectional images, especially for stereoscopic omnidirectional images. In this paper, based on the predictive coding theory of the human vision system (HVS), we propose a stereoscopic omnidirectional image quality evaluator (SOIQE) to cope with the characteristics of 3D 360-degree images. Two modules are involved in SOIQE: predictive coding theory based binocular rivalry module and multi-view fusion module. In the binocular rivalry module, we introduce predictive coding theory to simulate the competition between high-level patterns and calculate the similarity and rivalry dominance to obtain the quality scores of viewport images. Moreover, we develop the multi-view fusion module to aggregate the quality scores of viewport images with the help of both content weight and location weight. The proposed SOIQE is a parametric model without necessary of regression learning, which ensures its interpretability and generalization performance. Experimental results on our published stereoscopic omnidirectional image quality assessment database (SOLID) demonstrate that our proposed SOIQE method outperforms state-of-the-art metrics. Furthermore, we also verify the effectiveness of each proposed module on both public stereoscopic image datasets and panoramic image datasets

Simplified Neutrosophic Sets Based on Interval Dependent Degree for Multi-Criteria Group Decision-Making Problems

In this paper, a new approach and framework based on the interval dependent degree for multi-criteria group decision-making (MCGDM) problems with simplified neutrosophic sets (SNSs) is proposed. Firstly, the simplified dependent function and distribution function are defined. Then, they are integrated into the interval dependent function which contains interval computing and distribution information of the intervals

Information Flow Topology in Mixed Traffic: A Comparative Study between "Looking Ahead" and "Looking Behind"

The emergence of connected and automated vehicles (CAVs) promises smoother traffic flow. In mixed traffic where human-driven vehicles (HDVs) also exist, existing research mostly focuses on "looking ahead" (i.e., the CAVs receive information from preceding vehicles) strategies for CAVs, while recent work reveals that "looking behind" (i.e., the CAVs receive information from their rear vehicles) strategies might provide more possibilities for CAV longitudinal control. This paper presents a comparative study between these two types of information flow topology (IFT) from the string stability perspective, with the role of maximum platoon size (MPS) also under investigation. Precisely, we provide a dynamical modeling framework for the mixed platoon under the multi-predecessor-following (MPF) topology and the multi-successor-leading (MSL) topology. Then, a unified method for string stability analysis is presented, with explicit consideration of both IFT and MPS. Numerical results suggest that MSL ("looking behind") outperforms MPF ("looking ahead" ) in mitigating traffic perturbations. In addition, increasing MPS could further improve string stability of mixed traffic flow.Comment: This paper has been accepted by 26th IEEE International Conference on Intelligent Transportation Systems ITSC 202

Experimental Validation of DeeP-LCC for Dissipating Stop-and-Go Waves in Mixed Traffic

We present results on the experimental validation of leading cruise control (LCC) for connected and autonomous vehicles (CAVs). In a mixed traffic situation that is dominated by human-driven vehicles, LCC strategies are promising to smooth undesirable stop-and-go waves. Our experiments are carried out on a mini-scale traffic platform. We first reproduce stop-and-go traffic waves in a miniature scale, and then show that these traffic instabilities can be dissipated by one or a few CAVs that utilize Data-EnablEd Predicted Leading Cruise Control (DeeP-LCC). Rather than identifying a parametric traffic model, DeeP-LCC relies on a data-driven non-parametric behavior representation for traffic prediction and CAV control. DeeP-LCC also incorporates input and output constraints to achieve collision-free guarantees for CAVs. We experimentally demonstrate that DeeP-LCC is able to dissipate traffic waves caused by car-following behavior and significantly improve both driving safety and travel efficiency. CAVs utilizing DeeP-LCC may bring additional societal benefits by mitigating stop-and-go waves in practical traffic.Comment: 8 pages, 6 figure

PO-228 Effects of Different Cryotherapy Models on Timing Sequence Recovery of Exercise Induced Muscle Damage in Middle and Long Distance Runners

Objective Exercise induced muscle damage (EIMD) is one common physiological phenomenon in competitive sports and mass sports. Water immersion recovery and whole body cryotherapy (cryostimulation) (WBC) has become one of the fast recovery methods adopted by high level athletes in the world. The aim of this study was to compare the water immersion recovery and WBC from timing sequential recovery on EIMD, subjective scales, biochemical indicators, exercise performance indicators. Methods Twelve middle and long distance runners from Beijing Sport University were recruited in this study (exercise performance is secondary level in China). All participants performed four models in four weeks which included rest control (CON), cold water immersion(CWI), contrast water therapy (CWT) and whole body cryotherapy (cryostimulation) (WBC) separated by one week. The subjects needed to complete the EIMD exercise program, includes two parts: the treadmill running and the jump step. The individual speed of treadmill running was based on the individual VO2max. running including 5 sets and total time is about 90 min. Every set consist of 6 min flat running, 6 min uphill running and 6 min downhill running. The speed of the treadmill was stable in different stages. The slope of the uphill running is（＋6,＋5,＋4,＋3,＋2）, and the slope of downhill running is (-8, -7, -6, -5, -4). The jump was performed 20 times separated by 30 s via special step ( height is 40 cm) . After the EIMD exercise program, the subjects were treated with different recovery methods immediately after exercise, 24 h, 48 h, 72 h after exercise, while CON group received no intervention. The CWI group was immerged in 15 °C cold water for 12min, and the CWT groups was immerged in 15°C cold water for 1min and 38°C hot water for 1min with 6 cycles. The whole body cryotherapy (cryostimulation) group was immerged in special chamber (-110—-140℃）for 3 min. The three interventions were immerged body to the position of shoulders. The indexes including subjective scales (VAS scale, RPE scale, Borg scale, WHO deep sleep scale, PQSI scale), biochemical indicators (creatine kinase, lactate dehydrogenase, myoglobin, interleukin-6, C reactive protein, SICAM-1), exercise performance indicators ( vertical jump height, grip, running distance). The indexes was collected in different periods (i.e. Before exercise, immediately after exercise,Post1h, Post 24h, Post 48h, Post 72h, Post 96h after exercise etc.). Results  (1) Subjective scales. From results of VAS scale, RPE scale, and Borg scale, the WBC had best recovery effects than the other three interventions (P<0.05).  The recovery effect of the CWI group was similar with the CON group. From results of WHO deep sleep scale and PQSI scale, the WBC group had better recovery effects than CON group (P<0.05). (2) Biochemical indicators. From results of CK, Mb and SICAM-1, the WBC group had better recovery effect than the other three groups (P<0.05). In the LDH, the WBC group had similar effects with the CWT group (P>0.05). From results of CRP and IL-6, the WBC group had better recovery effects than the other three groups (P<0.05).（3）Exercise performance indicators. From results of vertical jump, WBC had lower decrease than the other three groups (P<0.05).  From results of the grip, of the WBC and CWT groups have significant retentive effects than CON group (P<0.05), but there was no significant difference between CON and CWI groups (P>0.05). Conclusions (1)Through combine the treadmill running and the jump step exercise program,Can effectively lead to human body appear the EIMD. (2)WBC has positive effects on the subjective scale, biochemical indicators, exercise performance indicators associated with EIMD.For middle and long distance runners EIMD,compared with CWI CWT,WBC effect is better.(3) CWI and CWT has a positive effect on some subjective scales, biochemical indicators, and exercise performance indicators related to EIMD. However, the positive effect of CWI and CWT is lower than WBC in the extent of action and timing sequence. (4)For the middle and long distance runners EIMD timing sequence recovery effects,WBC have better effects,Followed by CWT , CWI  effect is not significant