31 research outputs found

    Multi-Microgrid Collaborative Optimization Scheduling Using an Improved Multi-Agent Soft Actor-Critic Algorithm

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    The implementation of a multi-microgrid (MMG) system with multiple renewable energy sources enables the facilitation of electricity trading. To tackle the energy management problem of a MMG system, which consists of multiple renewable energy microgrids belonging to different operating entities, this paper proposes a MMG collaborative optimization scheduling model based on a multi-agent centralized training distributed execution framework. To enhance the generalization ability of dealing with various uncertainties, we also propose an improved multi-agent soft actor-critic (MASAC) algorithm, which facilitates en-ergy transactions between multi-agents in MMG, and employs automated machine learning (AutoML) to optimize the MASAC hyperparameters to further improve the generalization of deep reinforcement learning (DRL). The test results demonstrate that the proposed method successfully achieves power complementarity between different entities, and reduces the MMG system operating cost. Additionally, the proposal significantly outperforms other state-of-the-art reinforcement learning algorithms with better economy and higher calculation efficiency.Comment: Accepted by Energie

    Exploring Methods of the Sustainable Development for Safety Engineering International Course

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    To improve the effectiveness of the international course for safety engineering at China University of Mining & Technology (Beijing) (CUMTB), we explored sustainable development methods, co-occurrence analysis, statistical analysis, and questionnaire survey methods in a discussion of the international course’s current state and problems. First, the international course’s research topics and trends were analyzed. Second, other Chinese universities with international courses in safety engineering were counted. Finally, the international courses in safety engineering at CUMTB were analyzed from three aspects: teachers, teaching content, and course effect. The results show that there is a developing trend in international course research focusing on specific disciplines. For the safety engineering international course at CUMTB, foreign university teachers are the first choice for course instruction; however, the language barrier is a primary problem. In terms of teaching content, students are more interested in their intended employment fields and lack an understanding of various research fields. The course meets the students’ expectations but can still be improved. According to the results, we conclude that bilingual teaching by ethnic Chinese university teachers leads to more efficient knowledge acquisition. A guidance course and a survey of students’ employment intentions should be added before the course. Through these measures, the international course’s effectiveness and quality can be improved to better realize sustainable development

    Label Leakage and Protection in Two-party Split Learning

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    Two-party split learning is a popular technique for learning a model across feature-partitioned data. In this work, we explore whether it is possible for one party to steal the private label information from the other party during split training, and whether there are methods that can protect against such attacks. Specifically, we first formulate a realistic threat model and propose a privacy loss metric to quantify label leakage in split learning. We then show that there exist two simple yet effective methods within the threat model that can allow one party to accurately recover private ground-truth labels owned by the other party. To combat these attacks, we propose several random perturbation techniques, including Marvell\texttt{Marvell}, an approach that strategically finds the structure of the noise perturbation by minimizing the amount of label leakage (measured through our quantification metric) of a worst-case adversary. We empirically demonstrate the effectiveness of our protection techniques against the identified attacks, and show that Marvell\texttt{Marvell} in particular has improved privacy-utility tradeoffs relative to baseline approaches

    Wind tunnel modeling experiments on airflow characteristics of underground metro station with sunken squares

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    Building airflow characteristics can affect the indoor air environment, thereby affecting indoor air quality and building energy consumption. In recent years, the sunken square has increasingly designed and applied to underground transportation hub systems, because of their special advantages, such as improving the ventilation and lighting of the underground space, blurring the feeling of the ground and underground and improving the quality of the space. However, at present, there are few systematic and comprehensive researches on the airflow characteristics of the sunken squares to the underground metro station. In this study, the wind tunnel modeling experiment and the particle image velocity (PIV) technology are comprehensively used to study the influence of the sunken square on the airflow characteristics of the underground metro station, the influence of the sunken square on the flow field distribution and air exchange rate of underground metro station are obtained. The dimensionless average wind velocity at the large openings of the sunken square is 0.053-0.18, and the air exchange rate of the underground metro station is changed with the number and the relative positions of sunken squares. Conclusions of this research could provide useful reference to the design of airflow characteristics for underground buildings

    Genome Sequences of Marine Shrimp Exopalaemon carinicauda Holthuis Provide Insights into Genome Size Evolution of Caridea

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    Crustacea, particularly Decapoda, contains many economically important species, such as shrimps and crabs. Crustaceans exhibit enormous (nearly 500-fold) variability in genome size. However, limited genome resources are available for investigating these species. Exopalaemon carinicauda Holthuis, an economical caridean shrimp, is a potential ideal experimental animal for research on crustaceans. In this study, we performed low-coverage sequencing and de novo assembly of the E. carinicauda genome. The assembly covers more than 95% of coding regions. E. carinicauda possesses a large complex genome (5.73 Gb), with size twice higher than those of many decapod shrimps. As such, comparative genomic analyses were implied to investigate factors affecting genome size evolution of decapods. However, clues associated with genome duplication were not identified, and few horizontally transferred sequences were detected. Ultimately, the burst of transposable elements, especially retrotransposons, was determined as the major factor influencing genome expansion. A total of 2 Gb repeats were identified, and RTE-BovB, Jockey, Gypsy, and DIRS were the four major retrotransposons that significantly expanded. Both recent (Jockey and Gypsy) and ancestral (DIRS) originated retrotransposons responsible for the genome evolution. The E. carinicauda genome also exhibited potential for the genomic and experimental research of shrimps

    The Synergistic Activity of Rhamnolipid Combined with Linezolid against Linezolid-Resistant <i>Enterococcus faecium</i>

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    Enterococci resistance is increasing sharply, which poses a serious threat to public health. Rhamnolipids are a kind of amphiphilic compound used for its bioactivities, while the combination of nontraditional drugs to restore linezolid activity is an attractive strategy to treat infections caused by these pathogens. This study aimed to investigate the activity of linezolid in combination with the rhamnolipids against Enterococcus faecium. Here, we determined that the rhamnolipids could enhance the efficacy of linezolid against enterococci infections by a checkerboard MIC assay, a time–kill assay, a combined disk test, an anti-biofilm assay, molecular simulation dynamics, and mouse infection models. We identified that the combination of rhamnolipids and linezolid restored the linezolid sensitivity. Anti-biofilm experiments show that our new scheme can effectively inhibit biofilm generation. The mouse infection model demonstrated that the combination therapy significantly reduced the bacterial load in the feces, colons, and kidneys following subcutaneous administration. This study showed that rhamnolipids could play a synergistic role with linezolid against Enterococcus. Our combined agents could be appealing candidates for developing new combinatorial agents to restore antibiotic efficacy in the treatment of linezolid-resistant Enterococcus infections

    Whole Transcriptome Analysis Provides Insights into Molecular Mechanisms for Molting in <i>Litopenaeus vannamei</i>

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    <div><p>Molting is one of the most important biological processes in shrimp growth and development. All shrimp undergo cyclic molting periodically to shed and replace their exoskeletons. This process is essential for growth, metamorphosis, and reproduction in shrimp. However, the molecular mechanisms underlying shrimp molting remain poorly understood. In this study, we investigated global expression changes in the transcriptomes of the Pacific white shrimp, <i>Litopenaeus vannamei</i>, the most commonly cultured shrimp species worldwide. The transcriptome of whole <i>L</i>. <i>vannamei</i> was investigated by RNA-sequencing (RNA-seq) throughout the molting cycle, including the inter-molt (C), pre-molt (D0, D1, D2, D3, D4), and post-molt (P1 and P2) stages, and 93,756 unigenes were identified. Among these genes, we identified 5,117 genes differentially expressed (log<sub>2</sub>ratio ≥1 and FDR ≤0.001) in adjacent molt stages. The results were compared against the National Center for Biotechnology Information (NCBI) non-redundant protein/nucleotide sequence database, Swiss-Prot, PFAM database, the Gene Ontology database, and the Kyoto Encyclopedia of Genes and Genomes database in order to annotate gene descriptions, associate them with gene ontology terms, and assign them to pathways. The expression patterns for genes involved in several molecular events critical for molting, such as hormone regulation, triggering events, implementation phases, skelemin, immune responses were characterized and considered as mechanisms underlying molting in <i>L</i>. <i>vannamei</i>. Comparisons with transcriptomic analyses in other arthropods were also performed. The characterization of major transcriptional changes in genes involved in the molting cycle provides candidates for future investigation of the molecular mechanisms. The data generated in this study will serve as an important transcriptomic resource for the shrimp research community to facilitate gene and genome annotation and to characterize key molecular processes underlying shrimp development.</p></div

    Hierarchical clustering of 236 immunity genes.

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    <p>Colored keys represent the fold changes (log<sub>2</sub> transformed counts) of gene expression between adjacent molt stages Red represents up-regulation and green represents down-regulation. Each column represents an experimental condition (e.g. C-D0), and each row represents an immunity gene.</p

    Morphological changes of shrimp uropods during molting stages under a light microscope (400 Ă— magnification).

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    <p>Observed physical characteristics of each stage were as follows: 1) Inter-molt stage (C stage): mature setal cones and fully-spread epidermis. 2) Pre-molt stage (D stage): D0, a clear margin of epidermal tissue at the base of the setal cones. D1, a clear, narrow zone between the setal cones and the epidermis. D2, a wider clear zone and a wavy edge of epidermis. D3, a wider clear zone, highly wavy edge of epidermis, and a thin, white layer at the edge of the epidermis. D4, a noticeably wider clear zone, serrated edges of epidermis, a light-reflecting white layer at the edge of the epidermis, and parallel-band edepidermis. 3) Post-molt stage (P stage): P1, soft and delicate setae, absence of setal cones. P2, presence of young setal cones.</p
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