Non-intrusive Load Monitoring based on Self-supervised Learning

Deep learning models for non-intrusive load monitoring (NILM) tend to require a large amount of labeled data for training. However, it is difficult to generalize the trained models to unseen sites due to different load characteristics and operating patterns of appliances between data sets. For addressing such problems, self-supervised learning (SSL) is proposed in this paper, where labeled appliance-level data from the target data set or house is not required. Initially, only the aggregate power readings from target data set are required to pre-train a general network via a self-supervised pretext task to map aggregate power sequences to derived representatives. Then, supervised downstream tasks are carried out for each appliance category to fine-tune the pre-trained network, where the features learned in the pretext task are transferred. Utilizing labeled source data sets enables the downstream tasks to learn how each load is disaggregated, by mapping the aggregate to labels. Finally, the fine-tuned network is applied to load disaggregation for the target sites. For validation, multiple experimental cases are designed based on three publicly accessible REDD, UK-DALE, and REFIT data sets. Besides, state-of-the-art neural networks are employed to perform NILM task in the experiments. Based on the NILM results in various cases, SSL generally outperforms zero-shot learning in improving load disaggregation performance without any sub-metering data from the target data sets.Comment: 12 pages,10 figure

Effect of Double-Ovsynch and Presynch-Ovsynch on postpartum ovarian cysts and inactive ovary in high-yielding dairy cows

IntroductionOptimizing the management of dairy cattle reproduction can reduce postpartum ovarian disease in high-yielding dairy cows and thus enhance ranch economic benefit. The hypothesis of this study was that the Double-Ovsynch (DO) protocol in high-producing dairy cows would result in a lower incidence of follicular cysts but a higher incidence of luteal cysts compared to those undergoing the Presynch-Ovsynch (PS) protocol.MethodsIn this experiment, 384 cows (204 primiparous and 180 multiparous) were allocated to the DO group, which followed the protocol: GnRH-7d-PGF2α-3d-GnRH-7d-Ovsynch-56 h (GnRH-7d-PGF2α-56 h-GnRH-16hTAI), starting on 39 ± 3 days in milk (DIM). Additionally, 359 cows (176 primiparous and 183 multiparous) were assigned to the PS group, which followed the protocol: PGF2α-14d-PGF2α-12d-Ovsynch-56 h, starting on 31 ± 3 DIM. In DO, B-mode ultrasound examinations were conducted 1 day after the GnRH-7d-PGF2α-3d-GnRH protocol to diagnose the presence of ovarian diseases followed by reexamination after 7 days of suspected cases. In PS, B-mode ultrasound examinations were conducted 1 day after the PGF2α-14d-PGF2α protocol to diagnose the presence of ovarian diseases followed by reexamination after 7 days. For all cows confirmed to having ovarian diseases, a second B-mode ultrasound examination was conducted at the time of the second GnRH and timed artificial insemination (TAI). If the ovary showed a normal developing follicle in combination with normal ovulation, the ovarian disease was considered to be cured.ResultsThe current study revealed no significant difference in the overall incidence and cure rate of postpartum ovarian diseases between DO and PS (incidence rate: 3.9% vs. 6.7%, cure rate: 50% vs. 41.7%, DO vs. PS). Also, there was no significant difference in the incidence and cure rate of luteal cysts between DO and PS (incidence rate: 2.9% vs. 2.2%, cure rate: 50.0% vs. 50.0%). The incidence of follicular cysts was significantly lower in the DO group than in the PS group (0.8% vs. 2.8%, DO vs. PS, p = 0.037), but there was no significant difference in the cure rates (66.7% vs. 50%). The occurrence of inactive ovary was lower in DO compared to PS (0.2% vs. 1.7%, p = 0.047). There was no significant difference in the pregnancy rate between the DO and PS groups (48.2% vs. 41.8%), although the DO group had a higher rate. What is different from our assumption is that PS did not effectively reduce the incidence of postpartum luteal cysts

Extracellular electron transfer drives ATP synthesis for nitrogen fixation by Pseudomonas stutzeri

Biological nitrogen fixation is a key step in the reduction of N2 to available nitrogen in the global nitrogen cycle. Pseudomonas stutzeri A1501 is an electroactive diazotroph and previous studies have shown that its nitrogen fixation performance is better in a micro-oxygen environment than in an oxygen-free environment. In this study, a bioelectrochemical system (nitrogen fixation in an anode chamber) was set up to explore whether extracellular electrodes can replace oxygen in acting as electron acceptors to drive ATP synthesis for nitrogen fixation by P. stutzeri under oxygen-free conditions. Nitrogenase activity, extracellular NH4+ production, increase of total nitrogen, 15N/14N atom ratio and the genes related to nitrogen fixation by P. stutzeri in the anodic bioelectrochemical group under oxygen-free conditions were at least 1.64 times higher than the corresponding values without electron output to the anode. The planktonic cells in the anode chamber were responsible for most of the electron output via an electron shuttle–electron transfer pathway. The transmembrane proton motive force produced by the transfer of electrons from the intracellular environment to the anode drives ATP synthesis to meet the high energy demand of the nitrogen fixation reaction in the absence of O2. These findings provide a basis for optimization of the nitrogen fixing performance of P. stutzeri in an oxygen-free environment

ZrC–ZrB2–SiC ceramic nanocomposites derived from a novel single-source precursor with high ceramic yield

Abstract For the first time, ZrC–ZrB2–SiC ceramic nanocomposites were successfully prepared by a single-source-precursor route, with allylhydridopolycarbosilane (AHPCS), triethylamine borane (TEAB), and bis(cyclopentadienyl) zirconium dichloride (Cp2ZrCl2) as starting materials. The polymer-to-ceramic transformation and thermal behavior of obtained single-source precursor were characterized by means of Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The results show that the precursor possesses a high ceramic yield about 85% at 1000 °C. The phase composition and microstructure of formed ZrC–ZrB2–SiC ceramics were investigated by means of X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Meanwhile, the weight loss and chemical composition of the resultant ZrC–ZrB2–SiC nanocomposites were investigated after annealing at high temperature up to 1800 °C. High temperature behavior with respect to decomposition as well as crystallization shows a promising high temperature stability of the formed ZrC–ZrB2–SiC nanocomposites

Effects of whole-body vibration on sensorimotor deficits and brain plasticity among people with chronic ankle instability: a study protocol for a single-blind randomized controlled trial

Abstract Background Chronic ankle instability (CAI) is a form of musculoskeletal disease that can occur after a lateral ankle sprain, and it is characterized by pain, recurrent ankle sprains, a feeling of “giving way” at the ankle joint, and sensorimotor deficits. There has been increasing evidence to suggest that plastic changes in the brain after the initial injury play an important role in CAI. As one modality to treat CAI, whole-body vibration (WBV) has been found to be beneficial for treating the sensorimotor deficits accompanying CAI, but whether these benefits are associated with brain plasticity remains unknown. Therefore, the current study aims to investigate the effect of WBV on sensorimotor deficits and determine its correlation with plastic changes in the brain. Methods The present study is a single-blind randomized controlled trial. A total of 80 participants with CAI recruited from the university and local communities will be divided into 4 groups: whole-body vibration and balance training (WBVBT), balance training (BT), whole-body vibration (WBV), and control group. Participants will be given the WBV intervention (25-38 Hz, 1.3-2 mm, 3-time per week, 6-week) supervised by a professional therapist. Primary outcome measures are sensorimotor function including strength, balance, proprioception and functional performance. Brain plasticity will be evaluated by corticomotor excitability, inhibition, and representation of muscles, as measured by transcranial magnetic stimulation. Activation of brain areas will be assessed through functional near-infrared spectroscopy. Secondary outcome measures are self-reported functional outcomes involving the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure. All tests will be conducted before and after the WBV intervention, and at 2-week follow-up. Per‑protocol and intention-to-treat analysis will be applied if any participants withdraw. Discussion This is the first trial to investigate the role of brain plasticity in sensorimotor changes brought by WBV for individuals with CAI. As plastic changes in the brain have been an increasingly important aspect in CAI, the results of the current study can provide insight into the treatment of CAI from the perspective of brain plasticity. Trial registration Chinese Clinical Trial Registry (ChiCTR2300068972); registered on 02 March 2023