A Multiobjective Robust Scheduling Optimization Mode for Multienergy Hybrid System Integrated by Wind Power, Solar Photovoltaic Power, and Pumped Storage Power

Wind power plant (WPP), photovoltaic generators (PV), cell-gas turbine (CGT), and pumped storage power station (PHSP) are integrated into multienergy hybrid system (MEHS). Firstly, this paper presents MEHS structure and constructs a scheduling model with the objective functions of maximum economic benefit and minimum power output fluctuation. Secondly, in order to relieve the uncertainty influence of WPP and PV on system, robust stochastic theory is introduced to describe uncertainty and propose a multiobjective stochastic scheduling optimization mode by transforming constraint conditions with uncertain variables. Finally, a 9.6 MW WPP, a 6.5 MW PV, three CGT units, and an upper reservoir with 10 MW·h equivalent capacity are chosen as simulation system. The results show MEHS system can achieve the best operation result by using the multienergy hybrid generation characteristic. PHSP could shave peak and fill valley of load curve by optimizing pumping storage and inflowing generating behaviors based on the load supply and demand status and the available power of WPP and PV. Robust coefficients can relieve the uncertainty of WPP and PV and provide flexible scheduling decision tools for decision-makers with different risk attitudes by setting different robust coefficients, which could maximize economic benefits and minimize operation risks at the same time

A Genetic Algorithm-based BP Neural Network Method for Operational Performance Assessment of ATC Sector

To assess operational performance of air traffic control sector, a multivariate detection index system consisting of 5 variables and 17 indicators is presented, which includes operational trafficability, operational complexity, operational safety, operational efficiency, and air traffic controller workload. An improved comprehensive evaluation method, is designed for the assessment by optimizing initial weights and thresholds of back propagation (BP) neural network using genetic algorithm. By empirical study conducted in one air traffic control sector, 400 sets of sample data are selected and divided into 350 sets for network training and 50 sets for network testing, and the architecture of genetic algorithm-based back propagation (GABP) neural network is established as a three-layer network with 17 nodes in input layer, 5 nodes in hidden layers, and 1 node in output layer. Further testing with both GABP and traditional BP neural network reveals that GABP neural network performs betterthan BP neural work in terms of mean error, mean square error and error probability, indicating that GABP neural network can assess operational performance of air traffic control sector with high accuracy and stable generalization ability. The multivariate detection index system and GABP neural network method in this paper can provide comprehensive, accurate, reliable and practical operational performance assessment of air traffic control sector, which enable the frontline of air traffic service provider to detect and evaluate operational performance of air traffic control sector in real time, and trigger an alarm when necessary.</p

Quantifying the effects of five rehabilitation training methods on the ability of elderly men to control bowel movements: a finite element analysis study

PurposeThe study aims to develop a finite element model of the pelvic floor and thighs of elderly men to quantitatively assess the impact of different pelvic floor muscle trainings and the urinary and defecation control ability.MethodsA finite element model of the pelvic floor and thighs of elderly men was constructed based on MRI and CT. Material properties of pelvic floor tissues were assigned through literature review, and the relative changes in waistline, retrovesical angle (RVA) and anorectad angulation (ARA) to quantitatively verify the effectiveness of the model. By changing the material properties of muscles, the study analyzed the muscle strengthening or impairment effects of the five types of rehabilitation training for four types of urination and defecation dysfunction. The changes in four outcome indicators, including the retrovesical angle, anorectad angulation, stress, and strain, were compared.ResultsThis study indicates that ARA and RVA approached their normal ranges as material properties changed, indicating an enhancement in the urinary and defecation control ability, particularly through targeted exercises for the levator ani muscle, external anal sphincter, and pelvic floor muscles. This study also emphasizes the effectiveness of personalized rehabilitation programs including biofeedback, exercise training, electrical stimulation, magnetic stimulation, and vibration training and advocates for providing optimized rehabilitation training methods for elderly patients.DiscussionBased on the results of computational biomechanics, this study provides foundational scientific insights and practical recommendations for rehabilitation training of the elderly’s urinary and defecation control ability, thereby improving their quality of life. In addition, this study also provides new perspectives and potential applications of finite element analysis in elderly men, particularly in evaluating and designing targeted rehabilitation training

The Effect of Longitudinal Trajectories of Triglyceride-glucose Index on the New-onset Cardiovascular and Cerebrovascular Diseases

BackgroundTriglyceride glucose index (TyG) at baseline is an important influencing factor of cardiovascular and cerebrovascular diseases (CVD) , but there is still a lack of prospective cohort studies on the influence of TyG longitudinal trajectory on new-onset CVD at home and abroad.ObjectiveTo explore the influence of TyG longitudinal trajectory on the occurrence of new-onset CVD.MethodsThe Kailuan Study has been followed up every 2 years that began in 2006. A prospective cohort study method was used to select those who participated in three consecutive health examinations in 2006, 2008, and 2010, with complete triacylglycerol and blood glucose levels, and no history of malignant tumors, cardiovascular and cerebrovascular diseases as the observation objects. The 2010 health check-up time point was used as the starting point for the follow-up, and the occurrence of CVD, death or the end of the follow-up (2017-12-31) was used as the end point of the follow-up. SAS Proc Traj program was used to establish the trajectory model of the research object TyG, four different groups were determine daccording to the longitudinal trajectories of TyG: low-stable group, medium and low-stable group, medium and high-stable group, and high-stable group. The general data and laboratory observation indicatorsof the patients were collected and the Cox proportional hazard model was used to analyze the influence of TyG longitudinal trajectory on new-onset CVD.ResultsA total of 54 258 subjects meeting the inclusion criteriawere included, including 13 150 cases (24.24%) in the low-stable group, 28 488 cases (52.50%) in the medium-low-stable group, 10 808 cases (19.92%) in the medium-high-stable group, and 1 812 cases (3.34%) cases in the high-stable group. There were statistically significant differences in the age, gender, BMI, heart rate, TyG2006, TyG2008, TyG2010, HDL-C, LDL-C, UA, hs-CRP, TG, FBG, ALT, smoking, drinking, and physical exercise and the proportion of taking lipid-lowering drugs among different groups (P&lt;0.05) . The subjects were followed up for (6.73±1.12) years, and a total of 2 267 cases of CVD occurred, including 499 cases of acute myocardial infarction and 1 800 cases of stroke. There were significant difference in the cumulative incidence of CVD of patients among different TyG longitudinal trajectory groups (P&lt;0.05) . Cox regression analysis showed after adjusting for confounding factors, the HR value (95%CI) of CVD in each group were 1.29 (1.14, 1.46) , 1.40 (1.20, 1.63) and 1.76 (1.41, 2.20) when compared with the low-stable group; the HR value (95%CI) for acute myocardial infarctionwere 1.48 (1.10, 1.98) , 1.91 (1.36, 2.69) and 2.03 (1.22, 3.36) in each group when compared with the low-stable group; the HR value (95%CI) for stroke were 1.23 (1.07, 1.42) , 1.27 (1.07, 1.50) and 1.63 (1.27, 2.08) in each group; the HR value (95%CI) for ischemic strokewere 1.25 (1.08, 1.45) , 1.35 (1.12, 1.60) and 1.77 (1.37, 2.30) in each group.ConclusionThe increased longitudinal trajectory of TyG index is a risk factor for the incidence of CVD and is independent of the baseline of TyG index

Circulating Lysophosphatidylcholines in Early Pregnancy and Risk of Gestational Diabetes in Chinese Women.

ObjectivesThis study aimed to explore associations of lysophosphatidylcholines (LPCs) in early pregnancy with gestational diabetes mellitus (GDM), and whether LPCs mediated the associations of bile acids with GDM risk or had interactive effects with bile acids on GDM risk.DesignWe conducted a 1:1 nested case-control study (n = 486) from a large prospective pregnant women cohort in urban Tianjin, China. Blood samples were collected at their first antenatal care visit (median at 10th gestational week). LPCs were measured by liquid chromatography-tandem mass spectrometry analysis. Conditional binary logistic regression and restricted cubic spline analysis were used to identify cutoff points of these metabolites for GDM risk.ResultsOf the 6 detectable LPCs, LPC14:0 less than 0.24 nmol/mL, LPC15:0 at 0.45 nmol/mL or greater, and LPC18:0 at 18.00 nmol/mL or greater were independently associated with GDM risk. Adjustment for LPC18:0 slightly attenuated odds ratios (ORs) of deoxycholic acid (DCA, ≤ 0.36 nmol/mL) and glycoursodeoxycholic acid (GUDCA, ≤ 0.07 nmol/mL) for GDM, and the correlations of DCA and GUDCA with LPC18:0 were weak. However, the presence of DCA at 0.36 nmol/mL or less greatly amplified the adjusted OR of LPC18:0 at 18.00 nmol/mL or greater alone for GDM from 8.18 (2.51-26.7) up to 17.7 (6.64-47.1), with significant additive interaction. Similarly, the presence of GUDCA at 0.07 nmol/mL or less also greatly amplified the adjusted OR of LPC18:0 at 18.00 nmol/mL or greater alone for GDM from 17.2 (1.77-168) up to 73.8 (12.7-429), with significant additive interaction.ConclusionsLPCs in early pregnancy were associated with GDM risk. Low DCA or GUDCA greatly amplified the effect of high LPC18:0 on GDM, and its molecular mechanism is worth further investigations

Robust purchase and sale transactions optimization strategy for electricity retailers with energy storage system considering two-stage demand response

A new two-stage demand response is designed for the electricity retailers with energy storage system (ESS-ER) in the deregulated power market. The ESS-ER could response to the output of different power sources by adjusting the charging-discharging behavior according to the bidding power price. The paper models the two-stage demand response for electric power retailers and proposed a two-layer coordinated optimal model for the purchase and sale of the electric power retailers. In the upper layer model, the conditional value at risk method and robust stochastic theory are applied to describe the uncertainty influence of wind power and Photovoltaic (PV) power, and the minimum whole cost of power purchasing is taken as the objective. In the lower-layer, the power consumption behaviors of different customers are considered to get the maximum revenue of power selling by implementing differentiated demand response. Then, to solve the two-layer mathematical model, the lower-layer model is converted into the Karush-Kuhn-Tucker (KKT) optimality conditions. The results show that: (1) The two-stage demand response could smooth the curves of power purchasing and terminal users’ load, which could bring more flexible transaction space. (2) The proposed two-layer transaction model could balance the cost and risk of power purchasing, bringing more trading opportunities for wind power and PV, which can also reduce the energy consumption cost of the end-users. (3) By introducing the risk cost coefficient, confidence degree and robust coefficient, the decision-makers can adjust the power trading behaviors, and establish the optimal power trading scheme in line with their expected situation. (4) When higher energy storage capacity is set, the efficiency of demand response rises. When the capacity ratio of wind to energy storage is 4:1, the efficiency of demand response reaches the best. When larger energy storage capacity is set, the demand response turns to be more effective. However, when the capacity ratio of wind and PV to energy storage is 4:1, the effect of demand response reaches the best. Overall, the proposed model could provide an effective tool for power retailers in China's electric power market