1,016 research outputs found

    DisDiff: Unsupervised Disentanglement of Diffusion Probabilistic Models

    Full text link
    Targeting to understand the underlying explainable factors behind observations and modeling the conditional generation process on these factors, we connect disentangled representation learning to Diffusion Probabilistic Models (DPMs) to take advantage of the remarkable modeling ability of DPMs. We propose a new task, disentanglement of (DPMs): given a pre-trained DPM, without any annotations of the factors, the task is to automatically discover the inherent factors behind the observations and disentangle the gradient fields of DPM into sub-gradient fields, each conditioned on the representation of each discovered factor. With disentangled DPMs, those inherent factors can be automatically discovered, explicitly represented, and clearly injected into the diffusion process via the sub-gradient fields. To tackle this task, we devise an unsupervised approach named DisDiff, achieving disentangled representation learning in the framework of DPMs. Extensive experiments on synthetic and real-world datasets demonstrate the effectiveness of DisDiff.Comment: Accepted by NeurIPS 202

    An adaptive reclosing scheme based on phase characteristics for MMC-HVDC systems

    Get PDF
    To improve the reliability of power supply, reclosing schemes are required after transient faults, which commonly occur in overhead line based high voltage DC (HVDC) systems. However, in the event of permanent faults, the auto-reclosing scheme may cause a severe strike. To avoid the severe impacts caused by permanent faults, the fault type should be discriminated before activating the reclosing scheme. Therefore, an adaptive reclosing scheme based on phase characteristics is proposed in this paper. Firstly, the modulation of a periodic voltage by actively controlling the hybrid DC circuit breaker (DCCB) is introduced. Then, a cascaded π equivalent model and its decoupling algorithm are presented to analyze the frequency-domain characteristics of the measured impedance of the coupled overhead lines. From the frequency-domain characteristics, the frequency of the periodic detecting voltage is determined to analyze the phase features of the measured impedance at primary frequency. The permanent or transient faults can thus be accurately identified by using these different phase characteristics, with negligible influence on the healthy lines. In addition, the proposed scheme is robust to various fault resistances, leading to improved reliability. The effectiveness of the proposed scheme is verified in PSCAD/EMTDC

    An integrated control and protection scheme based on FBSM-MMC active current limiting strategy for DC distribution network

    Get PDF
    DC faults can easily lead to overcurrent in DC distribution networks; these faults pose serious threats to the safe operation of the system. The blocking of modular multilevel converters based on the full-bridge sub-modules (FBSM-MMC) is mostly utilized to cut off the fault current. However, the blocking causes short-term blackouts in the entire DC distribution network and there are presently no effective solutions to address this problem. In this study, an integrated control and protection scheme based on the FBSM-MMC active current limiting strategy is proposed. The project includes three stages: first, MMC active current limiting strategy is used to limit the output current of the converter to about 1.2 p.u. after the occurrence of the fault (Stage 1); next, faulty lines are identified based on the asynchronous zero-crossing features of the DC currents of the two ends of the line (Stage 2); then, a fault isolation scheme based on the cooperation of converters, DC circuit breakers, and high-speed switches is proposed to isolate the faulty line (Stage 3). The distribution network can restart quickly via control of the converters. Finally, the simulation of a four-terminal flexible DC distribution network in PSCAD/EMTDC demonstrates the effectiveness of the proposed integrated scheme

    Penggunaan Media Kartu Bergambar Dalam Pengembangan Materi Ajar Buku Hanyu Tingli Jiaocheng Untuk Mata Kuliah Menyimak I Dan II Bahasa Mandarin

    Full text link
    This research focused on the study on the development of teaching materials using the instructional media card with a picture in a book “Hanyu Tingli Jiaocheng” especially vocabulary as supporting the learning process. The choosing of appropriate learning media supported the teaching-learning process. The choosing of the media must be done carefully using many considerations to achieve the target of learning in facilitating the learners. This research was conducted on the Mandarin Listening I and II. Approproate teaching materials are needed to support teachers who teach this course. This study used qualitative research. The research was done in the Basic Class I and Basic Class II. The result showed that the Mandarin students got new concept for Mandarin learning process

    Audio Deepfake Detection Based on a Combination of F0 Information and Real Plus Imaginary Spectrogram Features

    Full text link
    Recently, pioneer research works have proposed a large number of acoustic features (log power spectrogram, linear frequency cepstral coefficients, constant Q cepstral coefficients, etc.) for audio deepfake detection, obtaining good performance, and showing that different subbands have different contributions to audio deepfake detection. However, this lacks an explanation of the specific information in the subband, and these features also lose information such as phase. Inspired by the mechanism of synthetic speech, the fundamental frequency (F0) information is used to improve the quality of synthetic speech, while the F0 of synthetic speech is still too average, which differs significantly from that of real speech. It is expected that F0 can be used as important information to discriminate between bonafide and fake speech, while this information cannot be used directly due to the irregular distribution of F0. Insteadly, the frequency band containing most of F0 is selected as the input feature. Meanwhile, to make full use of the phase and full-band information, we also propose to use real and imaginary spectrogram features as complementary input features and model the disjoint subbands separately. Finally, the results of F0, real and imaginary spectrogram features are fused. Experimental results on the ASVspoof 2019 LA dataset show that our proposed system is very effective for the audio deepfake detection task, achieving an equivalent error rate (EER) of 0.43%, which surpasses almost all systems

    Update on the Clinical Effect of Acupuncture Therapy in Patients with Gouty Arthritis: Systematic Review and Meta-Analysis

    Get PDF
    Objective. The aim of this study is to evaluate the clinical efficacy and safety of acupuncture therapy in the treatment of acute gouty arthritis. Methods. A literature search of PubMed, EMBASE, ISI Web of Science, CENTRAL, and CNKI was conducted from the inception date of each database up to October 2015. Two investigators screened each article independently and were blinded to the findings of the other reviewer. Data was extracted according to the predetermined collection form. Meta-analysis was performed. Results. We analyzed data from 28 RCTs involving 2237 patients with gouty arthritis. Compared with conventional pharmacological treatments acupuncture was more effective in rendering patients free from symptoms after 24 hours, lowering serum urate, alleviating pain associated with gouty arthritis, and decreasing the ESR; regarding CRP, no statistically significant difference was found. In addition, the frequency of adverse events in acupuncture treatment was lower than that in control group. Conclusion. Based on the findings of our study, we cautiously suggest that acupuncture is an effective and safe therapy for patients with gouty arthritis. However, the potential beneficial effect of acupuncture might be overstated due to the methodological deficiency of included studies. High quality RCTs with larger scale are encouraged

    Drug and therapeutics committee interventions in managing irrational drug use and antimicrobial stewardship in China

    Get PDF
    Aim: This study aimed to investigate the key points in the transformation of the functions of the Drug and Therapeutics Committee (DTC) of the Shandong Provincial Third Hospital and how to provide full authority to its role in the control of rational drug use, especially in the management of antibiotic use.Method: A prescription review management group, antimicrobial stewardship group, and rational drug use service group were established under the DTC. From January 2016 to December 2021, each group played a role in promoting rational drug use and antimicrobial stewardship. In addition, we performed statistics on typical management cases, irrational drug use, bacterial resistance rate, and drug costs from 2015 to 2021 to evaluate the effect of management by the DTC.Results: Intervention by the DTC led to a significant reduction in prescribing errors (71.43%, p < 0.05), the intervention acceptance rate increased by 16.03%, and the problem solved rate increased by 32.41% (p < 0.05). Resistance rates of general spectrum antibiotics were reduced remarkably after the intervention. The quality of drug treatment was improved and patient drug expenses was continuously reduced.Conclusion: Giving full play to the functions of the DTC can significantly improve the level of drug treatment and reduce unreasonable drug use to save unnecessary drug expenses and slow the development of drug resistance

    Necrostatin-1 Attenuates Trauma-Induced Mouse Osteoarthritis and IL-1β Induced Apoptosis via HMGB1/TLR4/SDF-1 in Primary Mouse Chondrocytes

    Get PDF
    Necrostatin-1 (Nec-1) is a specific small molecule inhibitor of receptor-interacting protein kinase 1 (RIPK1) that specifically inhibits phosphorylation of RIPK1. RIPK1 regulates inflammation and cell death by interacting with receptor-interacting serine/threonine protein kinases 3(RIPK3). We hypothesized that Nec-1 may have anti-inflammatory efficacy in patients with osteoarthritis (OA), as the pathophysiology of OA involves the activation of inflammation-related signaling pathways and apoptosis. In this study, we explored the effects of Nec-1 on interleukin (IL)-1β-induced inflammation in mouse chondrocytes and the destabilised medial meniscus (DMM) mouse model. Inhibiting RIPK1 with Nec-1 dramatically suppressed catabolism both in vivo and in vitro, but did not inhibit changes in subchondral bone. Nec-1 abolished the in vitro increases in matrix metalloproteinase (MMP) and ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTs5) expression induced by IL-1β. However, adding high-mobility group box 1 (HMGB1) partially abrogated this effect, indicating the essential role of HMGB1 and Nec-1 in the protection of primary chondrocytes. Furthermore, Nec-1 decreased the expression of Toll-like receptor 4 (TLR4) and stromal cell-derived factor-1 (SDF-1), and attenuated the interaction between TLR4 and HMGB1. Western blot results suggested that Nec-1 significantly suppressed IL-1β-induced NF-κB transcriptional activity, but not MAPK pathway. Micro-computed tomography, immunohistochemical staining, and Safranin O/Fast Green staining were used in vivo to assess the degree of destruction of OA cartilage. The results show that NEC-1 can significantly reduce the degree of destruction of OA cartilage. Therefore, Nec-1 may be a novel therapeutic candidate to treat OA

    Genome and transcriptome analysis of Enterococcus faecium from intestinal colonization and Enterococcus faecium from urinary tract infection

    Get PDF
    IntroductionEnterococcus faecium is a common pathogen responsible for urinary tract infections (UTIs) and often establishes extensive colonization within the intestinal tract. Our aim was to assess the genomic and transcriptomic differences between colonized E. faecium without UTI (only-colonization) and colonized E. faecium causing UTI (endogenous infections).MethodWe investigated the correlation between fecal isolates from the same patient and UTI-causing isolates using PFGE and WGS, and classified fecal isolates into two groups: those that solely colonized and those associated with endogenous urinary tract infections. We characterized the genomes of colonization-only and endogenously infected isolates by Scoary GWAS, and the transcriptomes of the isolates at 3 h urine exposure to assess pathogen-related changes.ResultBased on PFGE and WGS, eight isolates of endogenously infected E. faecium and nine isolates of only-colonized E. faecium were characterized and carbon and nitrogen regulated metabolisms such as genes encoding the phosphotransferase (PTS) system were enriched in endogenously infected E. faecium. Transcriptome analysis revealed significant differences in gene expression in the PTS system, lysine synthesis, galactose metabolism and citrate import between endogenously infected and only-colonized E. faecium isolates, highlighting the important role of certain carbon regulatory genes in the colonization and survival of endogenously infected E. faecium.ConclusionIn only-colonized and endogenously infected isolates, we observed differential expression patterns of genes related to carbon metabolism and amino acids, suggesting that metabolic diversity is a strategy for isolates leading to endogenous infection
    corecore