In this paper, an inexact proximal-point penalty method is studied for constrained optimization problems, where the objective function is non-convex, and the constraint functions can also be ...non-convex. This method approximately solves a sequence of subproblems, each of which is formed by adding to the original objective function a proximal term and quadratic penalty terms associated to the constraint functions. Under a weak-convexity assumption, each subproblem is made strongly convex and can be solved effectively to a required accuracy by an optimal gradient-based method. The computational complexity of this approach is analyzed separately for the cases of convex constraint and non-convex constraint. For both cases, the complexity results are established in terms of the number of proximal gradient steps needed to find an
ε
-stationary point. When the constraint functions are convex, we show a complexity result of
O
~
(
ε
-
5
/
2
)
to produce an
ε
-stationary point under the Slater’s condition. When the constraint functions are non-convex, the complexity becomes
O
~
(
ε
-
3
)
if a non-singularity condition holds on constraints and otherwise
O
~
(
ε
-
4
)
if a feasible initial solution is available.
•All patients' clinical symptoms improved significantly after surgery.•It can reduce the chance of mucosa tear and accelerate postoperative recovery.•No complications were found.•It’s especially ...suitable for the septal deviation with spur.
To introduce our method managing nasal septal spurs during endoscopic septoplasty.
We conducted a prospective study of cases treated with endoscopic septoplasty between March 2022 and June 2023. We innovated a surgical method to reduce the local mucosal tension at the spur by cutting the spur above and below the bony connection, and reducing the chance of mucosal tear and loss during dissection. The authors performed these cases at the First Affiliated Hospital of Fujian Medical University, where 40 surgeries were performed with regular postoperative follow-ups for 6–12 months.
All patients' clinical symptoms improved significantly after surgery. After 2–4 weeks of follow-up, the mucosa could recover to the preoperative state on both sides of the nasal septum.
This surgical method is suitable for most patients with nasal septal deviation, especially those with a spur, which can effectively reduce the chance of nasal septal mucosa tear and accelerate postoperative recovery.
Ⅳ.
Vagal reflexes regulate homeostasis in visceral organs and systems through afferent and efferent neurons and nerve fibers. Small, unmyelinated, C-type afferents comprise over 80% of fibers in the ...vagus and form the sensory arc of autonomic reflexes of the gut, lungs, heart and vessels and the immune system. Selective bioelectronic activation of C-afferents could be used to mechanistically study and treat diseases of peripheral organs in which vagal reflexes are involved, but it has not been achieved.
We stimulated the vagus in rats and mice using trains of kHz-frequency stimuli. Stimulation effects were assessed using neuronal c-Fos expression, physiological and nerve fiber responses, optogenetic and computational methods.
Intermittent kHz stimulation for 30 min activates specific motor and, preferentially, sensory vagus neurons in the brainstem. At sufficiently high frequencies (>5 kHz) and at intensities within a specific range (7–10 times activation threshold, T, in rats; 15-25 × T in mice), C-afferents are activated, whereas larger, A- and B-fibers, are blocked. This was determined by measuring fiber-specific acute physiological responses to kHz stimulus trains, and by assessing fiber excitability around kHz stimulus trains through compound action potentials evoked by probing pulses. Aspects of selective activation of C-afferents are explained in computational models of nerve fibers by how fiber size and myelin shape the response of sodium channels to kHz-frequency stimuli.
kHz stimulation is a neuromodulation strategy to robustly and selectively activate vagal C-afferents implicated in physiological homeostasis and disease, over larger vagal fibers.
•Selective activation of small visceral vagus afferents has not been achieved. .•kHz stimulation (kS) activates motor and mostly sensory vagal neurons in brainstem. .•kS activates afferent while blocking larger efferent fibers in rats and mice. .•Afferent fiber selectivity is frequency- and intensity-dependent. .•Selectivity is explained by how fiber size and myelin shape Na-channel responses. .
Precompression is vital when performing gastrointestinal anastomosis with staplers. However, research on the internal changes in intestinal tissue under stapling is lacking, and the effects of ...precompression have not been clarified. In this study, a stapler was modified, and the multifrequency bioimpedance of porcine small intestinal tissue was measured from before clamping the tissue with the stapler until the release of the tissue after precompression without firing. The Cole
model was fitted to the bioimpedance, and the changes in the tissue were analyzed using the model parameters: G
, extracellular fluid conductance, and Δ G, intracellular fluid conductance. The results show that the changes of G
and Δ G could be divided into four stages: rapid decrease, slow decrease, intense resilience, and slow recovery. During slow decrease stage, there was a greater decrease of G
and Δ G (1.02E-05 ± 1.12E-05 S and 1.73E-05 ± 2.12E-05 S in precompression time's increase, 1.68E-05 ± 8.74E-06 S and 1.20E-05 ± 1.09E-05 S in precompression strength's increase). On the contrary, during intense resilience stage, there was a less increase of G
and Δ G (0.88E-05 ± 4.86E-05 S and 9.15E-05 ± 9.37E-05 S in precompression time's increase, 2.72E-05 ± 3.53E-05 S and 1.02E-04 ± 8.54E-05 S in precompression strength's increase). In conclusion, the effects of precompression factors on tissue have been preliminary revealed: the tissue under precompression becomes thinner and less resilient. To improve the precompression effects and reduce any excessive pressure exerted on the staples by tissue resilience, the precompression time and strength should be increased appropriately.
We consider optimization problems with an objective function that is the sum of two convex terms: one is smooth and given by a black-box oracle, and the other is general but with a simple, known ...structure. We first present an accelerated proximal gradient (APG) method for problems where the smooth part of the objective function is also strongly convex. This method incorporates an efficient line-search procedure, and achieves the optimal iteration complexity for such composite optimization problems. In case the strong convexity parameter is unknown, we also develop an adaptive scheme that can automatically estimate it on the fly, at the cost of a slightly worse iteration complexity. Then we focus on the special case of solving the
ℓ
1
-regularized least-squares problem in the high-dimensional setting. In such a context, the smooth part of the objective (least-squares) is not strongly convex over the entire domain. Nevertheless, we can exploit its restricted strong convexity over sparse vectors using the adaptive APG method combined with a homotopy continuation scheme. We show that such a combination leads to a global geometric rate of convergence, and the overall iteration complexity has a weaker dependency on the restricted condition number than previous work.
The biocompatible strechable ionogels were prepared by a facile solution-processed method. The ionogels showed outstanding stretchable and self-healing properties. The electrical property could ...revert to its original state after 4 s. The repaired ionogels could still bear stretching about 150%. Moreover, the ionogels exhibited high sensitivity and wide-detection range to temperature. The temperature-sensitive sensor could detect the human breath frequency and intensity, showing potential application in detecting disease.
Abstract-In this article, we consider the nonparametric regression problem with multivariate predictors. We provide a characterization of the degrees of freedom and divergence for estimators of the ...unknown regression function, which are obtained as outputs of linearly constrained quadratic optimization procedures; namely, minimizers of the least-squares criterion with linear constraints and/or quadratic penalties. As special cases of our results, we derive explicit expressions for the degrees of freedom in many nonparametric regression problems, for example, bounded isotonic regression, multivariate (penalized) convex regression, and additive total variation regularization. Our theory also yields, as special cases, known results on the degrees of freedom of many well-studied estimators in the statistics literature, such as ridge regression, Lasso and generalized Lasso. Our results can be readily used to choose the tuning parameter(s) involved in the estimation procedure by minimizing the Stein's unbiased risk estimate. As a by-product of our analysis we derive an interesting connection between bounded isotonic regression and isotonic regression on a general partially ordered set, which is of independent interest.
Supplementary materials
for this article are available online.
A novel wearable human-machine interface (W-HMI) is purposed based on the signals processing system and arrayed strain sensors. Utilizing the coupling effects of different sensors to different eyes’ ...motions, the W-HMI can control the movements of UAV to the Right, Left, UP and Down. Importantly, the W-HMI based on the destroyed sensors also stably controls the movement of UAV.
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•A novel wearable human-machine interface (W-HMI) was proposed based on self-healing arrayed strain sensors.•The strain sensors showed high sensitivity, wide-detection range and excellent self-healing ability.•The proposed flexible and transparent W-HMI was capable of capturing eye motion.•The W-HMI could control the movement of the unmanned aerial vehicle (UAV) to the Right, Left, UP and Down.
Flexible strain sensors have been widely adopted for wearable systems in detecting the human activities and health. However, the demonstration of controlling interface based on strain sensor is still limited. Herein, a novel wearable human-machine interface (W-HMI) is proposed based on the signal processing system and self-healing strain sensors array. The strain sensor shows high sensitivity with the Gauge Factor max of 20, wide-detection range of 0.2–3000 % and self-healing ability. The proposed flexible and transparent W-HMI is capable of effectively capturing eyes' motions through four-array strain sensors. Based on the coupling effect of different sensors, W-HMI collects and processes the signals of the four sensors under different movements of the eyes, and then outputs different signals to control the right, left, up and down movements of the UAV. Importantly, the destroyed sensor can still show excellent performance due to its self-healing ability and can be used as a W-HMI to control the movement of UAV, which is an important characteristic to compensate for the vulnerability of W-HMI under continuous tension or extrusion. This innovative, cost-effective, simple-designed W-HMI based on the self-healing strain sensors will open a novel way to its application in the human-machine field.
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