Risk-return Efficiency, Financial Distress Risk, and Bank Financial Strength Ratings

This paper investigates whether there is any consistency between banks' financial strength ratings (bank rating) and their risk-return profiles. It is expected that banks with high ratings tend to earn high expected returns for the risks they assume and thereby have a low probability of experiencing financial distress. Bank ratings, a measure of a bank's intrinsic safety and soundness, should therefore be able to capture the bank's ability to manage financial distress while achieving risk-return efficiency. We first estimate the expected returns, risks, and financial distress risk proxy (the inverse z-score), then apply the stochastic frontier analysis (SFA) to obtain the risk-return efficiency score for each bank, and finally conduct ordered logit regressions of bank ratings on estimated risks, risk-return efficiency, and the inverse z-score by controlling for other variables related to each bank's operating environment. We find that banks with a higher efficiency score on average tend to obtain favorable ratings. It appears that rating agencies generally encourage banks to trade expected returns for reduced risks, suggesting that these ratings are generally consistent with banks' risk-return profiles.bank ratings; risk-return efficiency; stochastic frontier analysis

A new controller design of electro-hydraulic servo system based on empirical mode decomposition

The signal of electro-hydraulic servo system is non-stationary and time-varying due to the influence of vibration, noise and mechanical impact. The traditional digital filter always suffers delay in time domain and the delay increases along with the increasing of frequency. Considering the features of electro-hydraulic servo system, the Hilbert-Huang transform method is an effective method to decompose the original signal and obtain the noise components. Some improvements are made based on Hilbert Huang transform method and a new real time on-line filtering method is proposed in this paper. This improved filter is able to decompose out the noise components and other interference components from original signal, and remove them off in real time. Based on this new on-line filter, a new controller is also designed. Compared the filtering result with the traditional digital filter, this new controller’s control performance is much better

Modelling arterial pressure waveforms using Gaussian functions and two-stage particle swarm optimizer

Changes of arterial pressure waveform characteristics have been accepted as risk indicators of cardiovascular diseases. Waveform modelling using Gaussian functions has been used to decompose arterial pressure pulses into different numbers of subwaves and hence quantify waveform characteristics. However, the fitting accuracy and computation efficiency of current modelling approaches need to be improved. This study aimed to develop a novel two-stage particle swarm optimizer (TSPSO) to determine optimal parameters of Gaussian functions. The evaluation was performed on carotid and radial artery pressure waveforms (CAPW and RAPW) which were simultaneously recorded from twenty normal volunteers. The fitting accuracy and calculation efficiency of our TSPSO were compared with three published optimization methods: the Nelder-Mead, the modified PSO (MPSO), and the dynamic multiswarm particle swarm optimizer (DMS-PSO). The results showed that TSPSO achieved the best fitting accuracy with a mean absolute error (MAE) of 1.1% for CAPW and 1.0% for RAPW, in comparison with 4.2% and 4.1% for Nelder-Mead, 2.0% and 1.9% for MPSO, and 1.2% and 1.1% for DMS-PSO. In addition, to achieve target MAE of 2.0%, the computation time of TSPSO was only 1.5 s, which was only 20% and 30% of that for MPSO and DMS-PSO, respectively

Conjugated linoleic acid attenuates neuropathic pain induced by sciatic nerve in mice

Purpose: Conjugated linoleic acid (CLA) has been suggested to be necessary for human health, but there is limited research regarding its effect on neuropathic pain (NP). Here, we aim to investigate the potential effect of CLA administration on NP development and nerve recovery. Methods: Forty mice were divided into four equal groups randomly. The mice in control group underwent a sham operation to achieve a unilateral sciatic nerve cut. Other groups were subjected to partial sciatic nerve ligation (PSNL) surgery followed by 4 weeks of CLA treatment. Behavioral tests were performed shortly before mice were sacrificed. Blood, sciatic nerve and spinal cord tissues were collected after sacrifice. Electron microscopy was performed to determine myelin thickness and calculate myelin thickness/axon diameter ratio. Results: Mice that received daily oral CLA treatment for 4 weeks after PSNL surgery showed less mechanical and thermal allodynia than mice in PSNL surgery alone group. Behavioral tests showed that CLA treatment was associated with marked increases in both nerve conduction velocity (NCV) and force of gastrocnemius contraction. In addition, CLA reduced the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), sciatic myeloperoxidase (MPO) activity, and activating transcription factor-3 (ATF-3) expression. CLA also restored mitochondrial manganese superoxide dismutase (MnSOD) activity which was decreased in the sciatic nerves and spinal cords of the PSNL surgery group. Regeneration of myelins and axons in nerve fibers in CLA group was faster and more complete than that in the vehicle group. Conclusion: The current study demonstrates that CLA effectively attenuates NP and significantly inhibits neuro-inflammation and oxidative stress. This treatment improves sciatic nerve form and function after injury, suggesting that it can attenuate NP

Existence and blowup of solutions for non-divergence polytropic variation-inequality in corn option trading

This paper focuses on a class of variation-inequality problems involving non-divergence polytropic parabolic operators. The penalty method is employed, along with the Leray Schauder fixed point theory and limit progress, to determine the existence of solutions. The study also delves into the blow-up phenomena of the solution, revealing that under certain conditions, the solution will blow up in finite time

SSL-Auth: An Authentication Framework by Fragile Watermarking for Pre-trained Encoders in Self-supervised Learning

Self-supervised learning (SSL), utilizing unlabeled datasets for training powerful encoders, has achieved significant success recently. These encoders serve as feature extractors for downstream tasks, requiring substantial resources. However, the challenge of protecting the intellectual property of encoder trainers and ensuring the trustworthiness of deployed encoders remains a significant gap in SSL. Moreover, recent researches highlight threats to pre-trained encoders, such as backdoor and adversarial attacks. To address these gaps, we propose SSL-Auth, the first authentication framework designed specifically for pre-trained encoders. In particular, SSL-Auth utilizes selected key samples as watermark information and trains a verification network to reconstruct the watermark information, thereby verifying the integrity of the encoder without compromising model performance. By comparing the reconstruction results of the key samples, malicious alterations can be detected, as modified encoders won't mimic the original reconstruction. Comprehensive evaluations on various encoders and diverse downstream tasks demonstrate the effectiveness and fragility of our proposed SSL-Auth.Comment: Submitted to AAAI2024. 9 pages, 7 figure

Theoretical model and characteristics analysis of deflector-jet servo valve’s pilot stage

To analyze the deflector-jet servo valve’s internal flow characteristics, a theoretical model of the complicated flow distribution in the deflector plate is established based on the offset jet attachment theory. When the deflector plate offsets, jet attachment parameters are attained to figure out the jet’s bending and colliding process. On this basis, an analytical method of acquiring the pilot valve’s pressure gain is derived. According to an actual pilot stage’s structure, pressure gain calculations are carried out. Meanwhile, the pilot valve’s mesh model is established for numerical simulation in order to examine the accuracy of the theoretical model. Calculation and numerical simulation show that the final oil jet is not sensitive to the deflector plate’s movement, which directly reveals the pressure stabilizing effect of the V-shaped structure on the deflector plate. Moreover, the experiment on the pressure gain is accomplished and experiment results verify the accuracy of the analytical calculation