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Economic dispatch problems (EDPs) can be reduced to non-convex constrained optimization problems, and most of the population-based algorithms are prone to have problems of premature and falling into local optimum when solving EDPs. Therefore, this paper proposes a hybrid quantum-behaved particle swarm optimization (HQPSO) algorithm to alleviate the above problems. In the HQPSO, the Solis and Wets local search method is used to enhance the local search ability of the QPSO so that the algorithm can find solutions that is close to optimal when the constraints are met, and two evolution operators are proposed and incorporated for the purpose of making a better balance between local search and global search abilities at the later search stage. The performance comparison is made among the HQPSO and the other ten population-based random search methods under two different experimental configurations and four different power systems in terms of solution quality, robustness, and convergence property. The experimental results show that the HQPSO improves the convergence properties of the QPSO and finally obtains the best total generation cost without violating any constraints. In addition, the HQPSO outperforms all the other algorithms on 7 cases of all 8 experimental cases in terms of global best position and mean position, which verifies the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

The endwall effect has a great impact on the aerodynamic performance of compressor blades. Based on three conventional near-endwall blade modeling methods of bowed blade, endbend blade and leading-edge strake blade (LESB), two combined optimization design methods of highly loaded blades have been developed considering the endwall effect in the current study, i.e., the bowed blade combined with the LESB (bowed LESB blade) and the endbend blade combined with the LESB (endbend LESB blade). Optimization designs were conducted for a compressor cascade with low solidity by using the two combined modeling methods and the three conventional modeling methods, and the optimization results were compared and analyzed in detail. The results showed that the five optimization modelling methods could all improve the performance for the original cascade, and the optimized cascade with the bowed LESB modeling method has the best aerodynamic performance. The total pressure loss of the optimal bowed LESB cascade was only 40.3% of that in the original cascade while reducing the solidity of the original cascade from 1.53 to 1.25 and keeping the static pressure rise and diffusion factor at the same level as the original one. Among the optimal cascades, the radial migration height of the low-energy fluid and the corresponding vortex have great effects on the aerodynamic performance, and the optimal bowed LESB cascade is superior to the other optimal cascades in this aspect. [ABSTRACT FROM AUTHOR]

In this article, an improved Gaussian distribution based quantum-behaved particle swarm optimization (IG-QPSO) algorithm is proposed to solve engineering shape design problems with multiple constraints. In this algorithm, the Gaussian distribution is employed to generate the sequence of random numbers in the QPSO algorithm. By decreasing the variance of the Gaussian distribution linearly, the algorithm is able not only to maintain its global search ability during the early search stages, but can also obtain gradually enhanced local search ability in the later search stages. Additionally, a weighted mean best position in the IG-QPSO is employed to achieve a good balance between local search and global search. The proposed algorithm and some other well-known PSO variants are tested on ten standard benchmark functions and six well-studied engineering shape design problems. Experimental results show that the IG-QPSO algorithm can optimize these problems effectively in terms of precision and robustness compared to its competitors. [ABSTRACT FROM AUTHOR]

In this paper, we propose a particle swarm optimization method incorporating quantum qubit operation to construct and optimize fuzzy rule-based classifiers. The proposed algorithm, denoted as QiQPSO, is inspired by the quantum computing principles. It employs quantum rotation gates to update the probability of each qubit with the corresponding quantum angle updating according to the update equation of the quantum-behaved particle swarm optimization (QPSO). After description of the principle of QiQPSO, we show how to apply QiQPSO to establish a fuzzy classifier through two procedures. The QiQPSO algorithm is first used to construct the initial fuzzy classification system based on the sample data and the grid method of partitioning the feature space, and then the fuzzy rule base of the initial fuzzy classifier is optimized further by QiQPSO in order to reduce the number of the fuzzy rules and thus improve its interpretability. In order to verify the effectiveness of the proposed method, QiQPSO is tested on various real-world classification problems. The experimental results show that the QiQPSO is able to effectively select feature variables and fuzzy rules of the fuzzy classifiers with high classification accuracies. The performance comparison with other methods also shows that the fuzzy classifier optimized by QiQPSO has higher interpretability as well as comparable or even better classification accuracies. [ABSTRACT FROM AUTHOR]

GNSS spoofing interference utilizes falsified navigation signals to launch attacks on GNSS systems, posing a significant threat to applications that rely on GNSS signals for positioning, navigation, and time services. Therefore, achieving effective localization of the sources causing spoofing interference is crucial in ensuring the secure operation of GNSS. This article proposes a method for locating GNSS spoofing interference sources using a moving array antenna. Firstly, the proposed method utilizes the inherent characteristics of the double-differenced carrier phase from the deception signals received by the array antenna to effectively extract the spoofing signals. Subsequently, by moving the antenna array, the original carrier phase single-difference data of multiple observation points for deception signals are fused to provide a cost function for direct localization of spoofing interference, and a solution method for the cost function is designed. The proposed method addresses the challenge of extracting and localizing GNSS spoofing interference weak signals, effectively avoiding the data correlation of traditional two-step methods for DOA estimation parameters and ensuring the location accuracy of spoofing interference and the robustness of the method. The effectiveness of the proposed method has been validated through simulation experiments, and its adaptability to factors such as errors in carrier phase measurements has been examined. The method exhibits strong applicability and is well-suited for the hardware platform of the GNSS nulling antenna, thereby enabling it to possess simultaneous capabilities in both anti-interference and spoofing interference localization. [ABSTRACT FROM AUTHOR]

Continual relation extraction techniques aim to meet the requirements of real-world applications, in which new data and relations emerge constantly. To strike a balance between continual learning ability and computational cost, many previous works on replay-based methods emphasized on employing different strategies to use a smaller number of stored replay samples to maintain the continual ability of the model. However, catastrophic forgetting is prone to occur if a limited number of previously stored replay samples have been used. In this paper, we proposed a continual learning method which contains three learning phases, namely preliminary learning, memory retention, and memory reconsolidation. In more detail, the model is fine-tuned on the model of the last previous task firstly in the preliminary learning stage. During the memory retention stage, the method utilizes the characteristics of the model's linear mode connectivity between the multi-task learning model and the continual learning model to retain the knowledge of previous tasks as much as possible. At the memory reconsolidation stage, it uses the previously stored samples as well as the ones of the current task for interval cross training to reconsolidate the learned knowledge. In order to evaluate the continual learning ability of the model learning by the proposed method, we tested it on three well-studied benchmarks, and the experimental results show that our algorithm performs better than the other compared algorithms in terms of the average accuracy as well as overall accuracy. [ABSTRACT FROM AUTHOR]

Background: Previous economic studies conducted in developed countries showed intravenous tissue-type plasminogen activator (tPA) is cost-effective for acute ischemic stroke. The present study aimed to determine the cost-effectiveness of tPA treatment in China, the largest developing country. Methods: A combination of decision tree and Markov model was developed to determine the cost-effectiveness of tPA treatment versus non-tPA treatment within 4.5 hours after stroke onset. Outcomes and costs data were derived from the database of Thrombolysis Implementation and Monitor of acute ischemic Stroke in China (TIMS-China) study. Efficacy data were derived from a pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials. Costs and quality-adjusted life-years (QALYs) were compared in both short term (2 years) and long term (30 years). One-way and probabilistic sensitivity analyses were performed to test the robustness of the results. Results: Comparing to non-tPA treatment, tPA treatment within 4.5 hours led to a short-term gain of 0.101 QALYs at an additional cost of CNY 9,520 (US$ 1,460), yielding an incremental cost-effectiveness ratio (ICER) of CNY 94,300 (US$ 14,500) per QALY gained in 2 years; and to a long-term gain of 0.422 QALYs at an additional cost of CNY 6,530 (US$ 1,000), yielding an ICER of CNY 15,500 (US$ 2,380) per QALY gained in 30 years. Probabilistic sensitivity analysis showed that tPA treatment is cost-effective in 98.7% of the simulations at a willingness-to-pay threshold of CNY 105,000 (US$ 16,200) per QALY. Conclusions: Intravenous tPA treatment within 4.5 hours is highly cost-effective for acute ischemic strokes in China. [ABSTRACT FROM AUTHOR]

Background and Purpose: Few studies have reported on the risk factors of dilated Virchow-Robin Spaces (dVRS) in large samples of ischemic stroke patients. Little evidence exists regarding the relationship between dVRS and etiologic subtype of ischemic stroke or lacune. We aimed to investigate the risk factors associated with the severity of dVRS in a large sample of ischemic stroke patients. Methods: We consecutively enrolled 1,090 patients who experienced an ischemic stroke within the past seven days and underwent a 3.0 T MRI scan in the Chinese IntraCranial AtheroSclerosis Study (ICAS). Clinical data and cranial MRI information of patients included age, sex, vascular risk factors, dVRS, leukoaraiosis, lacune, and etiologic subtype of ischemic stroke. Analyses were performed regarding the risk factors associated with the severity of dVRS by univariate analysis and multivariable ordinal logistic regression analysis. Results: Through multivariable ordinal logistic regression analysis, age, the severity of leukoaraiosis, lacune, admission National Institutes of Health Stroke Scale (NIHSS) ≤3, and the severity of dVRS in the white matter (WM) and hippocampus (Hip) were correlated with the severity of dVRS in basal ganglia (BG); male, history of hypertension, admission NIHSS ≤3, and the severity of dVRS in BG and Hip were correlated with the severity of dVRS in WM; female, the severity of leukoaraiosis, admission NIHSS >3, small artery occlusion subtype of ischemic stroke, and the severity of dVRS in BG and WM were correlated with the severity of dVRS in Hip. Conclusion: dVRS is an indicator of cerebral small vessel diseases such as leukoaraiosis and lacune. However, the risk factors of dVRS differ in various brain regions. [ABSTRACT FROM AUTHOR]

Objective: Quality of care for Chinese patients with heart failure was substandard. This study aimed to ascertain the characteristics related to quality of care to narrow the gap.Methods: Data from 2064 heart failure patients between 1 January 2012 and 31 December 2015 at a hospital in Fujian Province were analyzed. The Bayesian network was used to assess the regulatory relationships between demographic and clinical characteristics and compliance with quality indicators.Results: The compliance with quality indicators ranged from 42.5% to 90.2%. The compliance with recommended doses for medications all reached or was close to 100% except indapamide. Residence place, hypertension, troponin, B-type natriuretic peptide, heart rate, lung disease, number of emergency treatments (ETs) and ejection fraction directly regulated the compliance, and gender, age, medical payment methods, myocardiopathy, coronary heart disease and arrhythmia indirectly regulated the compliance in the Bayesian network. The lower compliance was found in patients under ET, patients with abnormal testing indicators, patients without specific comorbidities and patients under the New Rural Cooperative Medical Scheme or self-paying. Patients with lung disease and those who lived in urban areas had a longer length of stay.Conclusions: The compliance with medication indicators for heart failure was suboptimal, but recommended doses were prescribed to patients who received medications. A series of strategies should be developed to improve the quality of care, such as expanding the scope and depth of knowledge of guidelines and clinical pathways, integrating the reminder and quality assessment model into the hospital medical record information system, paying more attention to the vulnerable population and improving the medical security system. [ABSTRACT FROM AUTHOR]

The seasonal properties and heat budget of marine heatwaves (MHWs) on the northern South China Sea (SCS) continental shelf are investigated. The winter MHWs are generally the warmest, gradually weakening in the following seasons. In winter and spring, all events have a temperature elevated by more than 1 °C while approximately half of the MHWs in summer and fall have temperatures elevated by less than 1 °C. The MHW duration is longest in winter, second longest in fall, and shortest in spring. Three types of MHWs have been defined based on the main heat source; i.e., air–sea heat flux dominant, ocean advection dominant, and mixed types. Air–sea heat flux is the dominant source for more than 80% of MHWs in winter and fall, ~ 70% of MHWs in spring, and ~ 50% in summer. There are slightly more ocean advection dominant events than Mixed-MHWs. Ocean advection always weakens an air–sea heat flux dominant MHW and enhances other types of events, so that the net heat supply is smallest for air–sea heat flux dominant MHW types. Ocean advection is mainly modulated by cross-slope water exchanges along the continental shelf edge. The offshore (onshore) cross-slope flow induces a negative (positive) contribution to MHW development. These results provide new insight into the seasonal cycle of MHWs on the northern SCS continental shelf. [ABSTRACT FROM AUTHOR]

This paper proposes the shrink Gaussian distribution quantum-behaved optimization (SG-QPSO) algorithm to solve economic dispatch (ED) problems from the power systems area. By shrinking the Gaussian probability distribution near the learning inclination point of each particle iteratively, SG-QPSO maintains a strong global search capability at the beginning and strengthen its local search capability gradually. In this way, SG-QPSO improves the weak local search ability of QPSO and meets the needs of solving the ED optimization problem at different stages. The performance of the SG-QPSO algorithm was obtained by evaluating three different power systems containing many nonlinear features such as the ramp rate limits, prohibited operating zones, and nonsmooth cost functions and compared with other existing optimization algorithms in terms of solution quality, convergence, and robustness. Experimental results show that the SG-QPSO algorithm outperforms any other evaluated optimization algorithms in solving ED problems. [ABSTRACT FROM AUTHOR]

This paper proposes the shrink Gaussian distribution quantum-behaved optimization (SG-QPSO) algorithm to solve economic dispatch (ED) problems from the power systems area. By shrinking the Gaussian probability distribution near the learning inclination point of each particle iteratively, SG-QPSO maintains a strong global search capability at the beginning and strengthen its local search capability gradually. In this way, SG-QPSO improves the weak local search ability of QPSO and meets the needs of solving the ED optimization problem at different stages. The performance of the SG-QPSO algorithm was obtained by evaluating three different power systems containing many nonlinear features such as the ramp rate limits, prohibited operating zones, and nonsmooth cost functions and compared with other existing optimization algorithms in terms of solution quality, convergence, and robustness. Experimental results show that the SG-QPSO algorithm outperforms any other evaluated optimization algorithms in solving ED problems. [ABSTRACT FROM AUTHOR]

This review mainly focuses on the topics related to metal complex based delayed fluorescence (DF) materials including their molecular design principle, photophysical studies, as well as their performance in the device settings. Due to the choice of various metal ions and metal complex system, metal based DF materials can be categorized into four major material classes based on their emission mechanisms at room temperature: (I) TADF materials exhibiting both fluorescence and DF; (II) TADF materials exhibiting DF only; (III) metal assisted delayed fluorescence (MADF) materials exhibiting both phosphorescence and DF; (IV) DF materials exhibiting fluorescence, phosphorescence and DF. Image 1 • This review focuses on recent progress of metal complex based delayed fluorescence materials. • Their molecular design principle, photophysical studies, as well as the device performance have been summarized. • These materials can be categorized into four major material classes based on their emission mechanisms. • An outlook on the future development of metal complex based delayed fluorescence materials is given. [ABSTRACT FROM AUTHOR]

The architectures of many state‐of‐the‐art local tempering detection models are complexity, and the training process of those models is also time‐consuming. Therefore, this paper constructs a lightweight local tampering detection method based on the convolutional network MobileNetV2 and a dual‐stream network. Specifically, the algorithm first improves the MobileNetv2, which not only reduces the multiple of its downsampling operator to retain richer traces of image tampering, but also introduces the dilated convolution in it to expand the receptive field of feature maps. The dual‐stream network uses RGB stream to extract image tampering features such as strong contrast difference and unnatural tampered boundaries, and implements spatial rich model (SRM) stream to extract image tampered area and noise features of real area. Finally, the features extracted from two streams are fused through an improved attention mechanism called parallel convolutional block attention module (CBAM), which can improve the sensitivity of the model to important features in RGB and SRM. The experimental results show that the proposed algorithm still has higher positioning accuracy than some existing algorithms, while achieving lightweight. [ABSTRACT FROM AUTHOR]

High spatial resolution bathymetric maps of coral reefs can show the details of terrain. However, most satellite-based imagery with a spatial resolution < 10 m has only three visible bands and one near-infrared (NIR) band. When in situ bathymetric data are unavailable, it is difficult to map bathymetry from high spatial resolution imagery with spectral matching or empirical models for clear or turbid waters. In this study, we developed a downscaled bathymetric mapping approach (DBMA) that uses the water depth estimated from multitemporal Landsat-8 data to calibrate the empirical model for high spatial resolution imagery (e.g., Sentinel-2A/B, GaoFen-1/2, ZiYuan-3, and WorldView-2) in the absence of in situ bathymetric data. Our results show that DBMA provides high accuracy for depth ranging from 0 to 12 m for clear waters (0 m to 5 m for turbid waters), with a root mean squared error (RMSE) smaller than 2 m. Relative to empirical models (calibrated with in situ data), DBMA underestimates water depth more for depth >12 m for clear waters (5 m for turbid waters) while slightly overestimates more for depth < 4 m for clear waters (3 m for turbid waters). Nevertheless, DBMA performs better than the empirical models for depth between 4 m and 12 m for clear waters (3 m and 5 m for turbid waters). Furthermore, the good performance of DBMA is also demonstrated by the finding that the scaling effect on the DBMA is limited. DBMA presents a reliable solution to obtain high spatial resolution bathymetric maps without leaving out small regions in the absence of in situ data. [ABSTRACT FROM AUTHOR]

To control tip leakage flow and reduce related loss in axial-flow compressors, the oscillating suction scheme was introduced in a high-load compressor cascade with a tip clearance, and its flow control mechanisms on the tip leakage flow were studied numerically. It is found that the flow control effect of oscillating suction is the best when the unsteady excitation frequency is equal or harmonic to the feature frequency of the flow field related to the flow separation. The loss of the cascade controlled by the oscillating suction with a reduced frequency of 0.39 and excitation amplitude of 10 kPa was reduced by about 3.4% compared with the steady suction scheme, and about 11.14% less than that of the non-suction scheme. Oscillating suction discretized the concentrated tip leakage vortex into a series of scale-reduced vortex structures by the periodic unsteady excitation, which can be identified by the analysis using proper orthogonal decomposition (POD). The feature frequencies became consistent with the oscillating excitation frequency or its multiple, and the fluctuation generated by the tip leakage flow was enhanced. The energy proportion of high-order POD modes was increased by oscillating excitation, which indicated the vortex structures with weak fluctuation intensity were more active. The mixing and energy exchange among the mainstream, separated flow, endwall secondary flow, and tip leakage flow were enhanced, so that a better flow control effect could be achieved. Furthermore, flow capacity of tip passage was modified, the overall aerodynamic performance of the compressor cascade was improved thereby. [ABSTRACT FROM AUTHOR]