299 research outputs found
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Monetary policy, cash holding and corporate investment: evidence from China
This paper uses 13,766 firm-year observations between 2003 and 2013 from China to investigate the effects of monetary policy on corporate investment and the mitigating effects of cash holding. We find that tightening monetary policy reduces corporate investment while cash holdings mitigate such adverse effects. The cash mitigating role is especially significant for financially constrained firms, non-state-owned enterprises (non-SOEs) and those firms located in a less developed financial market. Cash holding also improves investment efficiency when monetary policy is tightening and tightening monetary policy enhances the ‘cash-cash flow’ sensitivity. Our empirical evidence calls for a critical evaluation on the monetary policies implemented in China which are less effective for state-owned enterprises. It also calls for a necessity for local government to further develop regional financial markets to protect vulnerable businesses, such as non-SOEs and financially constrained firms, from external shocks in order to maintain their sustainable growth and competitive advantages
Landslide Surface Displacement Prediction Based on VSXC-LSTM Algorithm
Landslide is a natural disaster that can easily threaten local ecology,
people's lives and property. In this paper, we conduct modelling research on
real unidirectional surface displacement data of recent landslides in the
research area and propose a time series prediction framework named
VMD-SegSigmoid-XGBoost-ClusterLSTM (VSXC-LSTM) based on variational mode
decomposition, which can predict the landslide surface displacement more
accurately. The model performs well on the test set. Except for the random item
subsequence that is hard to fit, the root mean square error (RMSE) and the mean
absolute percentage error (MAPE) of the trend item subsequence and the periodic
item subsequence are both less than 0.1, and the RMSE is as low as 0.006 for
the periodic item prediction module based on XGBoost\footnote{Accepted in
ICANN2023}
A Worksite Occupational Health Clinic-Based Diabetes Mellitus Management Program
This study is an analysis of a workplace diabetes management program offered to employees of a Fortune 100 financial services corporation located in the United States. The 12-month worksite-based educational program was for employees who were at risk for diabetes, had prediabetes, or were diagnosed with diabetes. This employed population, with health benefits, generally had acceptable control of their diabetes at the start of the program. They statistically improved most self-efficacy measures, but improvement in biometric tests at 6 and 12 months were not significantly different from baseline. Mean hemoglobin A1c at baseline, 6 months, and 12 months was 7.2%, 7.2%, and 7.3%, respectively. At 12 months, about 40% of preprogram survey participants completed all screenings and the post-program questionnaire. Disease management programs at the workplace can be an important component in helping employees enhance their knowledge of diabetes and maintain and improve their health. (Population Health Management 2015;18:429?436)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140190/1/pop.2014.0141.pd
Tuning the detection wavelength of quantum-well infrared photodetectors by single high-energy implantation
Single high-energy (0.9 MeV) proton implantation and rapid thermal annealing was used to tune the spectral response of the quantum-well infrared photodetectors (QWIPs). In addition to the large redshift of the QWIPs’ response wavelength after implantation, either narrowed or broadened spectrum was obtained at different interdiffusion extent. In general, the overall device performance for the low-dose implantation was not significantly degraded. In comparison with the other implantation schemes, this single high-energy implantation is the most effective and simple technique in tuning the wavelength of QWIPs, thus, to achieve the fabrication of multicolor detectors.Partial financial support from Australian Research Council,
Hong Kong Research Grants Council, and the Australian
Agency for International Development ~AusAID! through
IDP Education Australia under Australia–China Institutional
Links Program (ACILP) is acknowledged
FaFCNN: A General Disease Classification Framework Based on Feature Fusion Neural Networks
There are two fundamental problems in applying deep learning/machine learning
methods to disease classification tasks, one is the insufficient number and
poor quality of training samples; another one is how to effectively fuse
multiple source features and thus train robust classification models. To
address these problems, inspired by the process of human learning knowledge, we
propose the Feature-aware Fusion Correlation Neural Network (FaFCNN), which
introduces a feature-aware interaction module and a feature alignment module
based on domain adversarial learning. This is a general framework for disease
classification, and FaFCNN improves the way existing methods obtain sample
correlation features. The experimental results show that training using
augmented features obtained by pre-training gradient boosting decision tree
yields more performance gains than random-forest based methods. On the
low-quality dataset with a large amount of missing data in our setup, FaFCNN
obtains a consistently optimal performance compared to competitive baselines.
In addition, extensive experiments demonstrate the robustness of the proposed
method and the effectiveness of each component of the model\footnote{Accepted
in IEEE SMC2023}
Socioeconomic Status and the Quality of Acute Stroke Care
Background and Purpose—The association of socioeconomic status (SES) with quality of stroke care is not well understood, and few studies have examined the association with different indicators of SES simultaneously. We assessed the impacts of low levels of education, occupation, and income on the quality of stroke care. Methods—We examined data from the China National Stroke Registry recording consecutive stroke patients between September 2007 and August 2008. Baseline low SES was measured using educational level <6 years, occupation as manual workers or no job, and average family income per capita at ≤¥1000 per month. Compliance with 11 performances was summarized in a composite score defined as the proportion of all needed care given. Poor quality of care was defined as having a composite score of 0.71 or less. Results—Among 12 270 patients with ischemic stroke, 38.6% had <6 educational years, 37.6% had manual workers/no job, and 34.7% had income ≤¥1000 per month. There was an increased chance of receiving poor quality of care in patients with low education (adjusted odds ratio 1.15, 95% confidence interval 1.03–1.28), low occupation (adjusted odds ratio 1.16, 95% confidence interval 1.01–1.32), and low income (adjusted odds ratio 1.18, 95% confidence interval 1.06–1.30), respectively. People with low SES had poor performances on some aspects of care quality. Combined effects existed among these SES indicators; those with low SES from all 3 indicators had the poorest quality of care. Conclusions—There was a social gradient in the quality of stroke care. Continuous efforts of socioeconomic improvement will increase the quality of acute stroke care.The Ministry of Science and Technology of the People’s Republic of China (2006BAI01A11, 2011BAI08B01, 2011BAI08B02, 2012ZX09303-005-001, and 2013BAI09B03), The Beijing Biobank of Cerebral Vascular Disease (D131100005313003), Beijing Institute for Brain Disorders (BIBD-PXM2013_014226_07_000084
Research on deep hole drilling vibration suppression based on magnetorheological fluid damper
Based on the working principle of magnetorheological fluid damping, in this paper, a set of squeezing mode Magneto-rheological Fluid (MRF) dampers is designed for drilling vibration suppression in deep hole machines. Elaborate analysis of the correlativity between the dynamic morphology trajectory of the machined hole surface, the vibration of the drilling tool-shaft, and the theoretical derivation of the damping force, is put forward in accordance with the Bingham model and Euler-Bernoulli beam Equation. Simultaneously, the contrast analysis of the vibration suppression effect is carried out through the drilling experiments with and without an MRF damper. In addition, a series of measurements on the vibration characteristics of the drilling shaft, the drilling tool and the guide surface wear patterns, and the machine hole surface are analyzed, respectively. Both the drilling experiments and theory studies have revealed that the strength of the magnetic field changed with the drill shaft at different levels of vibration. The MRF damper could suppress the vibration with nonlinear characteristics initiatively and instantaneously, by variable damping, which can eventually improve the surface roughness. In addition, according to the phenomenon of tool tipping, the breakage of the guide bars and the machine hole surface deduces the condition of the vibration effect objectively
OPR-Miner: Order-preserving rule mining for time series
Discovering frequent trends in time series is a critical task in data mining.
Recently, order-preserving matching was proposed to find all occurrences of a
pattern in a time series, where the pattern is a relative order (regarded as a
trend) and an occurrence is a sub-time series whose relative order coincides
with the pattern. Inspired by the order-preserving matching, the existing
order-preserving pattern (OPP) mining algorithm employs order-preserving
matching to calculate the support, which leads to low efficiency. To address
this deficiency, this paper proposes an algorithm called efficient frequent OPP
miner (EFO-Miner) to find all frequent OPPs. EFO-Miner is composed of four
parts: a pattern fusion strategy to generate candidate patterns, a matching
process for the results of sub-patterns to calculate the support of
super-patterns, a screening strategy to dynamically reduce the size of prefix
and suffix arrays, and a pruning strategy to further dynamically prune
candidate patterns. Moreover, this paper explores the order-preserving rule
(OPR) mining and proposes an algorithm called OPR-Miner to discover strong
rules from all frequent OPPs using EFO-Miner. Experimental results verify that
OPR-Miner gives better performance than other competitive algorithms. More
importantly, clustering and classification experiments further validate that
OPR-Miner achieves good performance
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