Optimizing the Location of Virtual Stations in Free-Floating Bike-Sharing Systems with the User Demand during Morning and Evening Rush Hours

In recent years, free-floating bike-sharing systems (FFBSSs) have been considerably developed in China. As there is no requirement to construct bike stations, this system can substantially reduce the cost when compared to the traditional bike-sharing systems. However, FFBSSs have also become a critical cause of parking disorder, especially during the morning and evening rush hours. To address this issue, the local governments stipulated that FFBSSs are required to deploy virtual stations near public transit stations and major establishments. Therefore, the location assignment of virtual stations is sufficiently considered in the FFBSSs, which is required to solve the parking disorder and satisfy the user demand, simultaneously. The purpose of this study is to optimize the location assignment of virtual stations that can meet the growing demand of users by analyzing the usage data of their shared bikes. This optimization problem is generally formulated as a mixed-integer linear programming (MILP) model to maximize the user demand. As an alternative solution, this article proposes a clustering algorithm, which can solve this problem in real time. The experimental results demonstrate that the MILP model and the proposed method are superior to the K-means method. Our method not only provides a solution for maximizing the user demand but also gives an optimized design scheme of the FFBSSs that represents the characteristics of virtual stations. Document type: Articl

Optimal moral-hazard-free reinsurance under extended distortion premium principles

We study an optimal reinsurance problem under a diffusion risk model for an insurer who aims to minimize the probability of lifetime ruin. To rule out moral hazard issues, we only consider moral-hazard-free reinsurance contracts by imposing the incentive compatibility constraint on indemnity functions. The reinsurance premium is calculated under an extended distortion premium principle, in which the distortion function is not necessarily concave. We first show that an optimal reinsurance contract always exists and then derive two sufficient and necessary conditions to characterize it. Due to the presence of the incentive compatibility constraint and the nonconcavity of the distortion, the optimal contract is obtained as a solution to a double obstacle problem. At last, we apply the general result to study three examples and obtain the optimal contract in (semi)closed form

Turbo-FLASH based arterial spin labeled perfusion MRI at 7 T.

Motivations of arterial spin labeling (ASL) at ultrahigh magnetic fields include prolonged blood T1 and greater signal-to-noise ratio (SNR). However, increased B0 and B1 inhomogeneities and increased specific absorption ratio (SAR) challenge practical ASL implementations. In this study, Turbo-FLASH (Fast Low Angle Shot) based pulsed and pseudo-continuous ASL sequences were performed at 7T, by taking advantage of the relatively low SAR and short TE of Turbo-FLASH that minimizes susceptibility artifacts. Consistent with theoretical predictions, the experimental data showed that Turbo-FLASH based ASL yielded approximately 4 times SNR gain at 7T compared to 3T. High quality perfusion images were obtained with an in-plane spatial resolution of 0.85×1.7 mm(2). A further functional MRI study of motor cortex activation precisely located the primary motor cortex to the precentral gyrus, with the same high spatial resolution. Finally, functional connectivity between left and right motor cortices as well as supplemental motor area were demonstrated using resting state perfusion images. Turbo-FLASH based ASL is a promising approach for perfusion imaging at 7T, which could provide novel approaches to high spatiotemporal resolution fMRI and to investigate the functional connectivity of brain networks at ultrahigh field

Study of wave propagation induced by sea dike breaching

In this paper, wave propagation induced by sea dike breaching is studied by physical model. Two sea dike layouts with seaside slope 1: 2 are applied. For layout A, inland area has the same elevations as the breach, and seaside water depth is 27.4cm. For layout B, inland area is 7cm lower than the breach, and seaside water depth is 34.4cm. Impacts of breach width, inland elevation, water depth and wave period on inundation area and overtopping discharge are carefully examined separately. Four breach widths, 5m, 10m, 15m and 20m, are selected. A series of irregular waves (JONSWAP ??=3.3) with mean wave periods 1.0s, 1.5s, 2.0s, and significant wave height 10 cm are applied at the offshore boundary for each layout. Several empirical formulas are proposed and indicate that change of inland area elevations affects the relationship among inundation area, overtopping discharge and breach width, wave propagation time and wave period. The correlation coefficient between calculated value and experimental data are very large, but some correlative value deviates a little from the ideal line, so in the future work, more factors should be considered, and the accuracy of the empirical formulas will be improved

Nominative Proxy Signature Schemes

In a nominative proxy signature scheme, an original singer delegates his signing power to a proxy, who generates a nominative signature on behalf of the original signer. In a nominative proxy signature scheme, only the nominee can verify the signature and if necessary, only the nominee can prove its validity to the third party. In this paper, we first classify the nominative proxy signature into two types, original-nominative proxy signature and proxy-nominative proxy signature. Then we analyze the nominative proxy scheme proposed by Park and Lee. We show that the scheme suffers from universal verification. We also point out that the scheme presented by S.-H. Seo and S.-H. Lee is insecure and the scheme cannot provide non-repudiation. Finally we present our nominative proxy signature schemes which overcome the weakness mentioned above. Compared with the scheme recently proposed by G.-L. Wang, our scheme is more efficient

Pulse shape discrimination based on the Tempotron: a powerful classifier on GPU

This study introduces the Tempotron, a powerful classifier based on a third-generation neural network model, for pulse shape discrimination. By eliminating the need for manual feature extraction, the Tempotron model can process pulse signals directly, generating discrimination results based on learned prior knowledge. The study performed experiments using GPU acceleration, resulting in over a 500 times speedup compared to the CPU-based model, and investigated the impact of noise augmentation on the Tempotron's performance. Experimental results showed that the Tempotron is a potent classifier capable of achieving high discrimination accuracy. Furthermore, analyzing the neural activity of Tempotron during training shed light on its learning characteristics and aided in selecting the Tempotron's hyperparameters. The dataset used in this study and the source code of the GPU-based Tempotron are publicly available on GitHub at https://github.com/HaoranLiu507/TempotronGPU.Comment: 14 pages,7 figure

Excisanin A suppresses proliferation by inhibiting hypoxiainducible factor-1α expression in human hepatocellular carcinoma cells

Purpose: To investigate the effect of excisanin A on human hepatocellular carcinoma cells as well as to elucidate its mechanism of action. Methods: Molecular docking was used to determine the binding characteristics of excisanin A to HIF-1α protein. The transcriptional activation and viability of excisanin A were assessed using Luciferase reporter and MTT assay. The HIF-1α protein in the nucleus was assayed using western blot and immunofluorescence. HIF-1α and VEGF mRNA levels were evaluated using reverse-transcription polymerase chain reaction (RT-PCR). Cell proliferation was determined by flow cytometry, as well as by EdU and clonogenic assays. In vivo tumor growth was assessed in a murine xenograft model of SKHep1 cells. Results: Excisanin A inhibited HIF-1α transcriptional activation, as well as HIF-1α protein synthesis (p < 0.001). Excisanin A also reduced VEGF protein and mRNA expressions (p < 0.001). In addition, the compound inhibited the proliferation of hepatocellular carcinoma cells. and tumor growth in the xenograft tumor model. Conclusion: Excisanin A is a potent HIF-1α inhibitor, supporting its potential development for human hepatoma therapy. Keywords: Excisanin A, HIF-1α, Protein synthesis, Hepatoma therap

Extraosseous (extramedullary) plasmacytomas: a clinicopathologic and immunophenotypic study of 32 Chinese cases

<p>Abstract</p> <p>Background</p> <p>Extraosseous plasmacytoma, so called extramedullary plasmacytoma (EMP) is relatively rare in China. The aim was investigate the clinicopathologic features of EMP and the role of Immunophenotype and genotype detection in diagnosis of EMP.</p> <p>Methods</p> <p>Thirty-two cases of EMP were investigated retrospectively by histopathology, immunophenotype, genotype and survival analysis.</p> <p>Results</p> <p>Clinically, the mean age of the patients was 53.4. Most of the patients received no treatment after the diagnosis was established, and the prognosis was relatively poor. Histologically, in 40% of the cases, the neoplastic cells were grade II or III. The neoplastic cells expressed one or more PC associated antigens. The immunophenotype of EMP and inflammation of sinonasal regions with numerous PC infiltrations were compared and showed some difference in expression of CD45, CD27, CD44v6 and Bcl-2 as well. Ig light chain restriction was detected in 87.5% of the cases.</p> <p>Conclusions</p> <p>we described 32 Chinese cases of EMP, compare with that reported in the literature, some differences are presented, including higher percentage of grade II and III cases, clinically inconsistent treatment and management as well as poor outcome of the disease.</p