6,915 research outputs found
A Novel Probabilistic Method for Energy Loss Estimation Using Minimal Line Current Information
Despite it is essential to distribution network economics, computing energy loss for most major networks is still a tough task due to the absence of full monitoring. Assume the line current follows a normal distribution, the sum of its square is a linear combination of independent chi-square variables, which follows a generalized noncentral chi-square distribution. Based on this finding, we develop a new probability-based analytical method to estimate distribution network energy losses efficiently. The proposed analytical method requires merely the knowledge of mean and variance of line current as well as the line resistance while provides a closed-form formula of the probability characteristics of energy loss. The method is demonstrated on a three-feeder radial network.<br/
Estimate the Probability Distribution of Imbalance-Induced Energy Loss with Minimal Data
Imbalance-induced energy loss accounts for a significant part of energy loss in low-voltage distribution networks. However, due to the prohibitive cost of full monitoring, high-resolution time-series data of low-voltage feeder currents are usually absent for accurate energy loss computation. This letter presents a novel method to estimate the probability distribution of imbalance-induced energy loss. In the proposed method, only the line resistance and statistical data (mean and covariance) of the phase currents are required to estimate imbalanced networks energy loss. Furthermore, a Bayesian statistics-based data-driven method is also proposed to get the mean and covariance value of phase current with minimal measurements. Numerical tests on a real three-phase imbalanced circuit show the proposed approach obtains the probability distribution of imbalance-induced energy loss with a low estimating error and low field measurement frequency.</p
Comparison of relapse rates, postoperative infections and operation time between BSSO and DO: a meta-analysis
Purpose: Differences in common complications and operation times suggest that complications after mandibular advancement surgery for Class II mandibular hypoplasia using bilateral sagittal split ramus osteotomy (BSSO) and distraction osteogenesis (DO) require further evaluation. The aim here is to compare relapse and postoperative infection incidences and operation times by meta-analysis to provide information for surgeons in selecting the appropriate surgical method and to inform patients about the complication risks of both.Method: A comprehensive search using Medline, PubMed, Web of Science, Cochrane Library, EBSCO, CQVIP, CBA, CNKI, and SinoMed and the Internet until February 2017 was performed. Only randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies (RS) were included. We performed study selection, data extraction, and risk of bias assessment and meta-analyses with fixed and random effects models based on statistical heterogeneity. Data were combined using Review Manager software.Results: In total, 388 articles were retrieved; 8 met our inclusion criteria: 4 RCTs, 1 CCT, and 3 RSs. Five of the included articles were analyzed regarding horizontal and vertical relapse. Although horizontal relapse was not significantly different between treatment options (P=0.65), vertical relapse was (P=0.03). Three and 2 studies were included in analyses of postoperative infections and of operation time; both showed significant differences between treatment options (P=0.0009 and P=0.006, respectively).Conclusion: This analysis revealed lower incidence rates of vertical relapse and postoperative infections after BSSO, with the operation time also being significantly shorter. More high-quality RCTs are needed for a more reliable and convincing conclusion
Prompt-aligned Gradient for Prompt Tuning
Thanks to the large pre-trained vision-language models (VLMs) like CLIP, we
can craft a zero-shot classifier by "prompt", e.g., the confidence score of an
image being "[CLASS]" can be obtained by using the VLM provided similarity
measure between the image and the prompt sentence "a photo of a [CLASS]".
Therefore, prompt shows a great potential for fast adaptation of VLMs to
downstream tasks if we fine-tune the prompt-based similarity measure. However,
we find a common failure that improper fine-tuning may not only undermine the
prompt's inherent prediction for the task-related classes, but also for other
classes in the VLM vocabulary. Existing methods still address this problem by
using traditional anti-overfitting techniques such as early stopping and data
augmentation, which lack a principled solution specific to prompt. We present
Prompt-aligned Gradient, dubbed ProGrad, to prevent prompt tuning from
forgetting the the general knowledge learned from VLMs. In particular, ProGrad
only updates the prompt whose gradient is aligned (or non-conflicting) to the
"general direction", which is represented as the gradient of the KL loss of the
pre-defined prompt prediction. Extensive experiments demonstrate the stronger
few-shot generalization ability of ProGrad over state-of-the-art prompt tuning
methods. Codes are available at https://github.com/BeierZhu/Prompt-align.Comment: Accepted by ICCV202
Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye
<p>Abstract</p> <p>Background</p> <p>Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the <it>Drosophila </it>eye. Here we report the isolation of a new loss-of-function <it>ras </it>allele, <it>ras</it><sup><it>KP</it></sup>, which causes excessive apoptosis in the <it>Drosophila </it>eye.</p> <p>Results</p> <p>This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress <it>ras</it><sup><it>KP</it></sup>-induced apoptosis, whereas the removal of <it>hid </it>only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the <it>ras</it><sup><it>KP </it></sup>cell death. In addition, we find a strong correlation between <it>ras</it><sup><it>KP</it></sup>-induced apoptosis in the eye disc and the activation of JNK signalling.</p> <p>Conclusion</p> <p>In the <it>Drosophila </it>eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.</p
Lead-free Pseudo-three-dimensional Organic-inorganic Iodobismuthates for Photovoltaic Applications
X-ray diffraction, electronic characterisation and mesoscopic solar cell evaluation were performed for two novel iodobismuthates, C5H6NBiI4 ([py][BiI4]) and C6H8NBiI4 ([mepy][BiI4]).</p
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