Self-Paced Learning: an Implicit Regularization Perspective

Self-paced learning (SPL) mimics the cognitive mechanism of humans and animals that gradually learns from easy to hard samples. One key issue in SPL is to obtain better weighting strategy that is determined by minimizer function. Existing methods usually pursue this by artificially designing the explicit form of SPL regularizer. In this paper, we focus on the minimizer function, and study a group of new regularizer, named self-paced implicit regularizer that is deduced from robust loss function. Based on the convex conjugacy theory, the minimizer function for self-paced implicit regularizer can be directly learned from the latent loss function, while the analytic form of the regularizer can be even known. A general framework (named SPL-IR) for SPL is developed accordingly. We demonstrate that the learning procedure of SPL-IR is associated with latent robust loss functions, thus can provide some theoretical inspirations for its working mechanism. We further analyze the relation between SPL-IR and half-quadratic optimization. Finally, we implement SPL-IR to both supervised and unsupervised tasks, and experimental results corroborate our ideas and demonstrate the correctness and effectiveness of implicit regularizers.Comment: 12 pages, 3 figure

Initial-boundary value problems for Poiseuille flow of nematic liquid crystal via full Ericksen-Leslie model

In this paper, we study the initial-boundary value problem for the Poiseuille flow of hyperbolic-parabolic Ericksen-Leslie model of nematic liquid crystals in one space dimension. Due to the quasilinearity, the solution of this model in general forms cusp singularity. We prove the global existence of H\"older continuous solution, which may include cusp singularity, for initial-boundary value problems with different types of boundary conditions.Comment: 36 pages, 3 figure

Event-related potential measures of the intending process: Time course and related ERP components

<p>Abstract</p> <p>Background</p> <p>The intending process plays an important part to the successful completion of many daily activities. However, few researchers have paid attention to this issue. This study was set to investigate the time course and the electrophysiological evidence of the intending process with a cue-respond task.</p> <p>Methods</p> <p>Event-related potentials (ERPs) were recorded while participants were performing different cued conditions (deceptive, truthful, and watch-only). The time course of intending process was analyzed through the different effect of the cue stimuli.</p> <p>Results</p> <p>The P2 component, that appeared between 200 and 400 ms after the cue was onset, can be observed in the intended conditions (deceptive, truthful), but cannot be found in un-intended condition (watch-only). The mean amplitude in P2 between the truthful and deceptive conditions was consistent with previous studies. P2 was thought to be the reflection of the intention process.</p> <p>Conclusions</p> <p>The results suggested that the intention process happened 200 to 400 ms after the cue stimuli was onset, and the P2 in the posterior scalp during this period could be a specific component that related with the process of intention.</p

Nitrate transporters in leaves and their potential roles in foliar uptake of nitrogen dioxideâ€

While plant roots are specialized organs for the uptake and transport of water and nutrients, the absorption of gaseous or liquid mineral elements by aerial plant parts has been recognized since more than one century. Nitrogen (N) is an essential macronutrient which generally absorbed either as nitrate (NO(−)(3)) or ammonium (NH(+)(4)) by plant roots. Gaseous nitrogen pollutants like N dioxide (NO(2)) can also be absorbed by plant surfaces and assimilated via the NO(−)(3) assimilation pathway. The subsequent NO(−)(3) flux may induce or repress the expression of various NO(−)(3)-responsive genes encoding for instance, the transmembrane transporters, NO(−)(3)/NO(−)(2) (nitrite) reductase, or assimilatory enzymes involved in N metabolism. Based on the existing information, the aim of this review was to theoretically analyze the potential link between foliar NO(2) absorption and N transport and metabolism. For such purpose, an overview of the state of knowledge on the NO(−)(3) transporter genes identified in leaves or shoots of various species and their roles for NO(−)(3) transport across the tonoplast and plasma membrane, in addition to the process of phloem loading is briefly provided. It is assumed that a NO(2)-induced accumulation of NO(−)(3)/NO(−)(2) may alter the expression of such genes, hence linking transmembrane NO(−)(3) transporters and foliar uptake of NO(2). It is likely that NRT1/NRT2 gene expression and species-dependent apoplastic buffer capacity may be also related to the species-specific foliar NO(2) uptake process. It is concluded that further work focusing on the expression of NRT1 (NRT1.1, NRT1.7, NRT1.11, and NRT1.12), NRT2 (NRT2.1, NRT2.4, and NRT2.5) and chloride channel family genes (CLCa and CLCd) may help us elucidate the physiological and metabolic response of plants fumigated with NO(2)

Brain activity in advantageous and disadvantageous situations: implications for reward/punishment sensitivity in different situations

OBJECTIVE: This study modeled win and lose trials in a simple gambling task to examine the effect of entire win-lose situations (WIN, LOSS, or TIE) on single win/lose trials and related neural underpinnings. METHODS: The behavior responses and brain activities of 17 participants were recorded by an MRI scanner while they performed a gambling task. Different conditions were compared to determine the effect of the task on the behavior and brain activity of the participants. Correlations between brain activity and behavior were calculated to support the imaging results. RESULTS: In win trials, LOSS caused less intense posterior cingulate activity than TIE. In lose trials, LOSS caused more intense activity in the right superior temporal gyrus, bilateral superior frontal gyrus, bilateral anterior cingulate, bilateral insula cortex, and left orbitofrontal cortex than WIN and TIE. CONCLUSIONS: The experiences of the participants in win trials showed great similarity among different win-lose situations. However, the brain activity and behavior responses of the participants in lose trials indicated that they experienced stronger negative emotion in LOSS. The participants also showed an increased desire to win in LOSS than in WIN or TIE conditions