181 research outputs found
A simple iterative algorithm for maxcut
We propose a simple iterative (SI) algorithm for the maxcut problem through
fully using an equivalent continuous formulation. It does not need rounding at
all and has advantages that all subproblems have explicit analytic solutions,
the cut values are monotonically updated and the iteration points converge to a
local optima in finite steps via an appropriate subgradient selection.
Numerical experiments on G-set demonstrate the performance. In particular, the
ratios between the best cut values achieved by SI and the best known ones are
at least and can be further improved to at least by a
preliminary attempt to break out of local optima.Comment: 30 pages, 1 figure. Subgradient selection, cost analysis and local
breakout are adde
UK credit and discouragement during the GFC
The availability of credit to entrepreneurs with good investment opportunities is an important facilitator of economic growth. Under normal economic conditions, most entrepreneurs who requested loans receive them. In a global financial crisis, popular opinion is that banks are severely restricting lending to smaller businesses. This assumes that low levels of investment are caused by supply-side restrictions in the credit market. Little is said about potential changes in the demand for credit and how it is influenced by entrepreneurs’ perceptions about supply-side restrictions. One particularly interesting, and under-researched, group of small businesses is that who have potentially good investment opportunities, but are discouraged from applying for external funding as they fear rejection. In this study, we question whether these entrepreneurs were correct in their assumptions. We find that levels of discouragement are quite low in general at 2.7 % of the total smaller business population. Further analysis implies that 55.6 % of discouraged borrowers would have got loans had they applied
Optimization study on longitudinal joints in quasi-rectangular shield tunnels
Featured Application: (1) The damage process of the newly adopted type of longitudinal joint with ductile iron joint panels (DIJPs) in quasi-rectangular tunnels was obtained. (2) The effect of bolt position improvements was investigated through joint tests. (3) Within the service conditions, the joint behavior could be divided into three stages under both positive and negative moments. (4) Effects of the modifications related to concrete and bolt properties were explored. (5) Through comparison, increasing the lever arm between bolts and the compression zone to resist exerted moments is believed to be the most effective optimization method.
There are large bending moments in quasi-rectangular shield tunnels due to their deviation from the circular shape, and as for other types of shield tunnels, the longitudinal joints are the most critical parts in the lining structure. A new type of joint with ductile iron joint panels (DIJPs) was installed in quasi-rectangular tunnels to solve these problems. The distance from the bolts to the segment's inner surface was improved for better performance under specific bending moment types. Both tests and finite element modeling (FEM) simulations were conducted to investigate the effect of the bolt position improvements. The resistances to crack appearance increased by 33.6% and 18.0% for positive and negative moment cases, respectively. The resistances to crack penetration increased by 13.8% and 18.4% for positive and negative cases. From the FEM approach, it was found that the behavior of the joint under the design bending moment range can be divided into three stages, whereby the bolts are only active from the second stage on. The effects of other optimizing methods, such as enhancement of concrete properties and increase of bolt diameters and numbers, are explored. Through comparison, it is believed that optimizing the joint section to increase the lever arm between bolts and the compression zone can improve the joint behavior most effectively. This optimization direction is recommended when designing a shield tunnel joint with DIJPs
Decomposed Human Motion Prior for Video Pose Estimation via Adversarial Training
Estimating human pose from video is a task that receives considerable
attention due to its applicability in numerous 3D fields. The complexity of
prior knowledge of human body movements poses a challenge to neural network
models in the task of regressing keypoints. In this paper, we address this
problem by incorporating motion prior in an adversarial way. Different from
previous methods, we propose to decompose holistic motion prior to joint motion
prior, making it easier for neural networks to learn from prior knowledge
thereby boosting the performance on the task. We also utilize a novel
regularization loss to balance accuracy and smoothness introduced by motion
prior. Our method achieves 9\% lower PA-MPJPE and 29\% lower acceleration error
than previous methods tested on 3DPW. The estimator proves its robustness by
achieving impressive performance on in-the-wild dataset
γ-Secretase Inhibitor Alleviates Acute Airway Inflammation of Allergic Asthma in Mice by Downregulating Th17 Cell Differentiation
T helper 17 (Th17) cells play an important role in the pathogenesis of allergic asthma. Th17 cell differentiation requires Notch signaling. γ-Secretase inhibitor (GSI) blocks Notch signaling; thus, it may be considered as a potential treatment for allergic asthma. The aim of this study was to evaluate the effect of GSI on Th17 cell differentiation in a mouse model of allergic asthma. OVA was used to induce mouse asthma model in the presence and absence of GSI. GSI ameliorated the development of OVA-induced asthma, including suppressing airway inflammation responses and reducing the severity of clinical signs. GSI also significantly suppressed Th17-cell responses in spleen and reduced IL-17 levels in serum. These findings suggest that GSI directly regulates Th17 responses through a Notch signaling-dependent pathway in mouse model of allergic asthma, supporting the notion that GSI is a potential therapeutic agent for the treatment of allergic asthma
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