Combined heat and power dynamic economic dispatch considering field operational characteristics of natural gas combined cycle plants

Combined heat and power dynamic economic dispatch (CHPDED) is one of the key technologies for the efficient operation of natural gas combined cycle (NGCC) plants in integrated energy systems. In this study, based on the actual operational characteristics of NGCC plants at combined heat and power mode, a plant advanced loads variation capacity model is developed. The advanced loads variation capacity models of NGCC plants are integrated into the CHPDED model to guarantee the feasibility of the dispatched demands. Moreover, a field operational data based simplification method for the advanced loads variation capacity model is proposed to alleviate the computational burden. The field operational data of an actual NGCC station is taken to perform case studies. The calculation cases show that all the dispatched demands calculated from the CHPDED model with advanced loads variation capacity models are feasible. Furthermore, the influence of the heat load variation process on the power load adjustment process is employed to achieve better dispatch results. Compared with CHPDED models in the existing research, the CHPDED model with advanced loads variation capacity models significantly improves the feasibility of the dispatched demands, thereby enhancing the real application value of CHPDED in the field operation of NGCC plants.acceptedVersio

An improved combined heat and power economic dispatch model for natural gas combined cycle power plants

An increasing number of natural gas combined cycle (NGCC) plants are operated under combined heat and power mode. Therefore, a combined heat and power economic dispatch (CHPED) is the key to achieve the optimal utilization of fuel. In this paper, an improved CHPED model is developed, in which short-term loads variation process models of plants are integrated to ensure the feasibility of dispatched demands. The short-term loads variation process of NGCC plants is modelled based on the power and heat loads control logic in the field operation process. In comparison with the CHPED models in most existing researches, the improved CHPED model can be applied in the real-time field operation of plants. In addition, the influence of heat load ramp rates on CHPED results is investigated, which can offer theoretical support and guidance for field operation. Based on the data from field operation and manufacturer of an NGCC power station, case studies are performed. Results show that the errors between the short-term loads variation process model and field operational data are less than 2.6 s on power load, and less than 1 s on heat load, which proves the accuracy of the model. All the dispatched demands of the improved CHPED model can be met in the required regulation time limits. On one-hour cumulative fuel consumption, the improved CHPED model saves 171.4 kg (0.12%) over the field operational demands. The improved CHPED model not only enhances the economic performance, but also guarantees the operational reliability of plants.acceptedVersion© 2020. This is the authors’ accepted and refereed manuscript to the article. Locked until 26.8.2022 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

Continuous Piecewise-Affine Based Motion Model for Image Animation

Image animation aims to bring static images to life according to driving videos and create engaging visual content that can be used for various purposes such as animation, entertainment, and education. Recent unsupervised methods utilize affine and thin-plate spline transformations based on keypoints to transfer the motion in driving frames to the source image. However, limited by the expressive power of the transformations used, these methods always produce poor results when the gap between the motion in the driving frame and the source image is large. To address this issue, we propose to model motion from the source image to the driving frame in highly-expressive diffeomorphism spaces. Firstly, we introduce Continuous Piecewise-Affine based (CPAB) transformation to model the motion and present a well-designed inference algorithm to generate CPAB transformation from control keypoints. Secondly, we propose a SAM-guided keypoint semantic loss to further constrain the keypoint extraction process and improve the semantic consistency between the corresponding keypoints on the source and driving images. Finally, we design a structure alignment loss to align the structure-related features extracted from driving and generated images, thus helping the generator generate results that are more consistent with the driving action. Extensive experiments on four datasets demonstrate the effectiveness of our method against state-of-the-art competitors quantitatively and qualitatively. Code will be publicly available at: https://github.com/DevilPG/AAAI2024-CPABMM

Lateral Buckling Analysis of the Steel-Concrete Composite Beams in Negative Moment Region

Distortional buckling is one of the important buckling models of steel-concrete composite beam in negative moment region. Rotation restraining rigidity and lateral restraining rigidity which steel beam web to bottom plate of steel-concrete composite are the key factors to influence the distortional buckling behavior. A comprehensive and intensive study on rotation restraining rigidity and lateral restraining rigidity which steel beam web to bottom plate of I-shaped steel-concrete composite beam in negative moment region is conducted in this paper. Energy variation principle is adopted to deduce the analytical expressions to calculate the rotation restraining rigidity and lateral restraining rigidity. Combined with the buckling theory of axial compression thin-walled bars in elastic medium, the buckling moment is obtained. Theoretical analysis shows that the rotation restraining rigidity and lateral restraining rigidity of steel beam web appear to have a linear relationship with the external loads and could also be negative. Compared with other methods, the results calculated by the proposed expressions agree well with the numerical results by ANSYS. The proposed expressions are more concise and suitable than the existing formulas for the engineering application

Interventions for treating depression after stroke

Background: Depression is an important consequence of stroke that impacts on recovery yet is often not detected or inadequately treated. This is an update of a Cochrane review first published in 2004. Objectives: To determine whether pharmaceutical, psychological, or electroconvulsive treatment (ECT) of depression in patients with stroke can improve outcome. Search strategy: We searched the trials registers of the Cochrane Stroke Group (last searched October 2007) and the Cochrane Depression Anxiety and Neurosis Group (last searched February 2008). In addition, we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2008), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006), CINAHL (1982 to May 2006), PsycINFO (1967 to May 2006) and other databases. We also searched reference lists, clinical trials registers, conference proceedings and dissertation abstracts, and contacted authors, researchers and pharmaceutical companies. Selection criteria: Randomised controlled trials comparing pharmaceutical agents with placebo, or various forms of psychotherapy or ECT with standard care (or attention control), in patients with stroke, with the intention of treating depression. Data collection and analysis: Two review authors selected trials for inclusion and assessed methodological quality; three review authors extracted, cross-checked and entered data. Primary analyses were the prevalence of diagnosable depressive disorder at the end of treatment. Secondary outcomes included depression scores on standard scales, physical function, death, recurrent stroke and adverse effects. Main results: Sixteen trials (17 interventions), with 1655 participants, were included in the review. Data were available for 13 pharmaceutical agents, and four trials of psychotherapy. There were no trials of ECT. The analyses were complicated by the lack of standardised diagnostic and outcome criteria, and differing analytic methods. There was some evidence of benefit of pharmacotherapy in terms of a complete remission of depression and a reduction (improvement) in scores on depression rating scales, but there was also evidence of an associated increase in adverse events. There was no evidence of benefit of psychotherapy. Authors' conclusions: A small but significant effect of pharmacotherapy (not psychotherapy) on treating depression and reducing depressive symptoms was found, as was a significant increase in adverse events. More research is required before recommendations can be made about the routine use of such treatments

Mining and analysis of dizziness adverse event signals in postoperative analgesia patients based on the FDA adverse event reporting system database

ObjectiveThis study aimed to explore the association between drugs used in postoperative anesthesia patients and postoperative dizziness using the U.S. Food and Drug Administration’s Adverse Event Reporting System (FAERS) database, along with other risk factors for dizziness.MethodsUsing the FAERS database, we retrospectively analyzed dizziness cases reported between 2004 and the third quarter of 2023. We analyzed the relationship between drugs during postoperative anesthesia and the risk of postoperative dizziness, and conducted subgroup analysis according to age, sex and other factors. Signal detection was further performed using the reported odds ratio (ROR) method to identify medications significantly associated with an increased risk of postoperative dizziness.ResultsA total of 166,292 dizziness case reports were obtained, with 128 cases specifically related to postoperative analgesia. The number of dizziness reports has been increasing yearly, with a higher concentration of cases among individuals aged 18–85 years, predominantly in female patients. The analysis identified that amitriptyline, clonazepam, and ketamine were significantly associated with an increased risk of dizziness, with RORs of 34.91, 17.39, and 7.37, respectively. Subgroup analyses revealed variations in the relative risk of dizziness based on sex and age groups. Ketamine may be associated with higher risk of dizziness in the adult male subgroup.ConclusionThe results of this study suggest that specific medications used by patients with postoperative analgesia are associated with an increased risk of postoperative dizziness. Future studies should further validate this finding and explore other potential risk factors