1,192 research outputs found
Beyond Probability Partitions: Calibrating Neural Networks with Semantic Aware Grouping
Research has shown that deep networks tend to be overly optimistic about
their predictions, leading to an underestimation of prediction errors. Due to
the limited nature of data, existing studies have proposed various methods
based on model prediction probabilities to bin the data and evaluate
calibration error. We propose a more generalized definition of calibration
error called Partitioned Calibration Error (PCE), revealing that the key
difference among these calibration error metrics lies in how the data space is
partitioned. We put forth an intuitive proposition that an accurate model
should be calibrated across any partition, suggesting that the input space
partitioning can extend beyond just the partitioning of prediction
probabilities, and include partitions directly related to the input. Through
semantic-related partitioning functions, we demonstrate that the relationship
between model accuracy and calibration lies in the granularity of the
partitioning function. This highlights the importance of partitioning criteria
for training a calibrated and accurate model. To validate the aforementioned
analysis, we propose a method that involves jointly learning a semantic aware
grouping function based on deep model features and logits to partition the data
space into subsets. Subsequently, a separate calibration function is learned
for each subset. Experimental results demonstrate that our approach achieves
significant performance improvements across multiple datasets and network
architectures, thus highlighting the importance of the partitioning function
for calibration
Deadline Constrained Cloud Computing Resources Scheduling through an Ant Colony System Approach
Cloud computing resources scheduling is essential for executing workflows in the cloud platform because it relates to both execution time and execution cost. In this paper, we adopt a model that optimizes the execution cost while meeting deadline constraints. In solving this problem, we propose an Improved Ant Colony System (IACS) approach featuring two novel strategies. Firstly, a dynamic heuristic strategy is used to calculate a heuristic value during an evolutionary process by taking the workflow topological structure into consideration. Secondly, a double search strategy is used to initialize the pheromone and calculate the heuristic value according to the execution time at the beginning and to initialize the pheromone and calculate heuristic value according to the execution cost after a feasible solution is found. Therefore, the proposed IACS is adaptive to the search environment and to different objectives. We have conducted extensive experiments based on workflows with different scales and different cloud resources. We compare the result with a particle swarm optimization (PSO) approach and a dynamic objective genetic algorithm (DOGA) approach. Experimental results show that IACS is able to find better solutions with a lower cost than both PSO and DOGA do on various scheduling scales and deadline conditions
Reparameterized Policy Learning for Multimodal Trajectory Optimization
We investigate the challenge of parametrizing policies for reinforcement
learning (RL) in high-dimensional continuous action spaces. Our objective is to
develop a multimodal policy that overcomes limitations inherent in the
commonly-used Gaussian parameterization. To achieve this, we propose a
principled framework that models the continuous RL policy as a generative model
of optimal trajectories. By conditioning the policy on a latent variable, we
derive a novel variational bound as the optimization objective, which promotes
exploration of the environment. We then present a practical model-based RL
method, called Reparameterized Policy Gradient (RPG), which leverages the
multimodal policy parameterization and learned world model to achieve strong
exploration capabilities and high data efficiency. Empirical results
demonstrate that our method can help agents evade local optima in tasks with
dense rewards and solve challenging sparse-reward environments by incorporating
an object-centric intrinsic reward. Our method consistently outperforms
previous approaches across a range of tasks. Code and supplementary materials
are available on the project page https://haosulab.github.io/RPG
An Efficient General-Purpose Modular Vision Model via Multi-Task Heterogeneous Training
We present a model that can perform multiple vision tasks and can be adapted
to other downstream tasks efficiently. Despite considerable progress in
multi-task learning, most efforts focus on learning from multi-label data: a
single image set with multiple task labels. Such multi-label data sets are
rare, small, and expensive. We say heterogeneous to refer to image sets with
different task labels, or to combinations of single-task datasets. Few have
explored training on such heterogeneous datasets. General-purpose vision models
are still dominated by single-task pretraining, and it remains unclear how to
scale up multi-task models by leveraging mainstream vision datasets designed
for different purposes. The challenges lie in managing large intrinsic
differences among vision tasks, including data distribution, architectures,
task-specific modules, dataset scales, and sampling strategies. To address
these challenges, we propose to modify and scale up mixture-of-experts (MoE)
vision transformers, so that they can simultaneously learn classification,
detection, and segmentation on diverse mainstream vision datasets including
ImageNet, COCO, and ADE20K. Our approach achieves comparable results to
single-task state-of-the-art models and demonstrates strong generalization on
downstream tasks. Due to its emergent modularity, this general-purpose model
decomposes into high-performing components, efficiently adapting to downstream
tasks. We can fine-tune it with fewer training parameters, fewer model
parameters, and less computation. Additionally, its modularity allows for easy
expansion in continual-learning-without-forgetting scenarios. Finally, these
functions can be controlled and combined to meet various demands of downstream
tasks
Thermalization Effect in semiconductor Si, and metallic silicide NiSi2, CoSi2 by using Non-Adiabatic Molecular Dynamics Approach
Recently, cold source transistor (CSFET) with steep-slope subthreshold swing
(SS) < 60 mV/decade has been proposed to overcome Boltzmann tyranny in its
ballistic regime. However the scattering, especially by inelastic scattering
may lead serious SS degradation through cold carrier thermalization. In this
study, the electronic excitation/relaxation dynamic process is investigated
theoretically by virtue of the state-of-the-art nonadiabatic molecular dynamics
(NAMD) method, i.e., the mixed quantum-classical NAMD. The mixed
quantum-classical NAMD considers both carrier decoherence and detailed balance
to calculate the cold carrier thermalization and transfer processes in
semiconductor Si, and metallic silicide (NiSi2 and CoSi2). The dependence of
the thermalization factor, relaxation time, scattering time and scattering rate
on energy level are obtained. The thermalization of carrier gradually increases
from low energy to high energy. Partially thermalization from the ground state
to reach the thermionic current window is realized with sub-100 time
scale. Fully thermalization to entail energy region depends on the barrier
height sensitively, i.e., the scattering rate decreases exponentially as the
energy of the out-scattering state increase. The scattering rate of NiSi2 and
CoSi2 is 2 orders of magnitude higher than that of Si, arising from their
higher density of states than that in Silicon This study can shed light on the
material design for low power tunneling FET as well as the emerging CSFET.Comment: 14 pages, 17 figre
Characterization of myeloperoxidase and its contribution to antimicrobial effect on extracellular traps in flounder (Paralichthys olivaceus)
Myeloperoxidase (MPO) is a cationic leukocyte haloperoxidase and together with other proteins, they possess activities against various microorganisms and are involved in extracellular trap (ET) formation. The present work describes the gene and deduced protein sequences, and functions of MPO in flounder (PoMPO). The PoMPO possesses a 2313 bp open reading frame (ORF) that encodes a protein of 770 amino acids. The highest PoMPO mRNA expression levels were found in the head kidney, followed by peritoneal cells, gill, spleen, skin, muscle, and liver. PoMPO was expressed in MHCII+ and GCSFR+ cells which indicated that PoMPO mainly is expressed in flounder macrophages and granulocytes. Bacterial lipopolysaccharide-stimulated peritoneal leukocytes showed an increased protein level of PoMPO while it seemed that LPS also promoted the migration of MPO+ cells from the head kidney into the peripheral blood and peritoneal cavity. After phorbol 12-myristate 13-acetate (PMA) or bacterial stimulation, flounder leukocytes produced typical ET structures containing DNA with decoration by MPO. The ETs containing DNA and PoMPO effectively inhibited the proliferation of ET-trapped bacteria. Blocking PoMPO with antibodies decreased the enzymatic activity, which attenuated the antibacterial activity of ETs. This study pinpoints the involvement of ETs in flounder innate responses to pathogens
Recommended from our members
Differential effects of partial and complete loss of TREM2 on microglial injury response and tauopathy.
Alzheimer's disease (AD), the most common form of dementia, is characterized by the abnormal accumulation of amyloid plaques and hyperphosphorylated tau aggregates, as well as microgliosis. Hemizygous missense variants in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) are associated with elevated risk for developing late-onset AD. These variants are hypothesized to result in loss of function, mimicking TREM2 haploinsufficiency. However, the consequences of TREM2 haploinsufficiency on tau pathology and microglial function remain unknown. We report the effects of partial and complete loss of TREM2 on microglial function and tau-associated deficits. In vivo imaging revealed that microglia from aged TREM2-haploinsufficient mice show a greater impairment in their injury response compared with microglia from aged TREM2-KO mice. In transgenic mice expressing mutant human tau, TREM2 haploinsufficiency, but not complete loss of TREM2, increased tau pathology. In addition, whereas complete TREM2 deficiency protected against tau-mediated microglial activation and atrophy, TREM2 haploinsufficiency elevated expression of proinflammatory markers and exacerbated atrophy at a late stage of disease. The differential effects of partial and complete loss of TREM2 on microglial function and tau pathology provide important insights into the critical role of TREM2 in AD pathogenesis
- …