63 research outputs found
Review of advances on longitudinal vibration of submarine propulsion shafting and its vibration reduction technology
Analyzed the formation mechanism of longitudinal vibration of the submarine propulsion shafting system, and introduced its existing vibration control technology. The content included the improvement design of propulsion shafting system, new types of thrust bearing, composite material shaft, dynamic vibration absorber, phonon crystal band gap damping and relative active control technology. A new method for the application of metal rubber technology in thrust bearing was put forward, which provided a new idea for the research work in the future
Dynamic Frequency Domain Graph Convolutional Network for Traffic Forecasting
Complex spatial dependencies in transportation networks make traffic
prediction extremely challenging. Much existing work is devoted to learning
dynamic graph structures among sensors, and the strategy of mining spatial
dependencies from traffic data, known as data-driven, tends to be an intuitive
and effective approach. However, Time-Shift of traffic patterns and noise
induced by random factors hinder data-driven spatial dependence modeling. In
this paper, we propose a novel dynamic frequency domain graph convolution
network (DFDGCN) to capture spatial dependencies. Specifically, we mitigate the
effects of time-shift by Fourier transform, and introduce the identity
embedding of sensors and time embedding when capturing data for graph learning
since traffic data with noise is not entirely reliable. The graph is combined
with static predefined and self-adaptive graphs during graph convolution to
predict future traffic data through classical causal convolutions. Extensive
experiments on four real-world datasets demonstrate that our model is effective
and outperforms the baselines
Habitat Use and Activity Patterns of Mammals and Birds in Relation to Temperature and Vegetation Cover in the Alpine Ecosystem of Southwestern China with Camera-Trapping Monitoring
The high-altitude ecosystem of the Tibetan Plateau in China is a biodiversity hotspot that provides unique habitats for endemic and relict species along an altitudinal gradient at the eastern edge. Acquiring biodiversity information in this area, where the average altitude is over 4000 m, has been difficult but has been aided by recent developments in non-invasive technology, including infrared-triggered camera trapping. We used camera trapping to acquire a substantial number of photographic wildlife records in Wolong National Nature Reserve, Sichuan, China, from 2013 to 2016. We collected information of the habitat surrounding the observation sites, resulting in a dataset covering 37 species and 12 environmental factors. We performed a multivariate statistical analysis to discern the dominant environmental factors and cluster the mammals and birds of the ecosystem in order to examine environmental factors contributing to the species’ relative abundance. Species were generalized into three main types, i.e., cold-resistant, phyllophilic, and thermophilic, according to the identified key environmental drivers (i.e., temperature and vegetation) for their abundances. The mammal species with the highest relative abundance were bharal (Pseudois nayaur), Moupin pika (Ochotona thibetana), and Himalayan marmot (Marmota himalayana). The bird species with highest relative abundance were snow partridge (Lerwa lerwa), plain mountain finch (Leucosticte nemoricola), Chinese monal (Lophophorus lhuysii), and alpine accentor (Prunella collaris)
Unsupervised Anomaly Detection via Variational Auto-Encoder for Seasonal KPIs in Web Applications
To ensure undisrupted business, large Internet companies need to closely
monitor various KPIs (e.g., Page Views, number of online users, and number of
orders) of its Web applications, to accurately detect anomalies and trigger
timely troubleshooting/mitigation. However, anomaly detection for these
seasonal KPIs with various patterns and data quality has been a great
challenge, especially without labels. In this paper, we proposed Donut, an
unsupervised anomaly detection algorithm based on VAE. Thanks to a few of our
key techniques, Donut greatly outperforms a state-of-arts supervised ensemble
approach and a baseline VAE approach, and its best F-scores range from 0.75 to
0.9 for the studied KPIs from a top global Internet company. We come up with a
novel KDE interpretation of reconstruction for Donut, making it the first
VAE-based anomaly detection algorithm with solid theoretical explanation.Comment: 12 pages (including references), 17 figures, submitted to WWW 2018:
The 2018 Web Conference, April 23--27, 2018, Lyon, France. The contents
discarded from the conference version due to the 9-page limitation are also
included in this versio
The Gut Microbiome Signatures Discriminate Healthy From Pulmonary Tuberculosis Patients
Cross talk occurs between the human gut and the lung through a gut-lung axis involving the gut microbiota. However, the signatures of the human gut microbiota after active Mycobacterium tuberculosis infection have not been fully understood. Here, we investigated changes in the gut microbiota in tuberculosis (TB) patients by shotgun sequencing the gut microbiomes of 31 healthy controls and 46 patients. We observed a dramatic changes in gut microbiota in tuberculosis patients as reflected by significant decreases in species number and microbial diversity. The gut microbiota of TB patients were mostly featured by the striking decrease of short-chain fatty acids (SCFAs)-producingbacteria as well as associated metabolic pathways. A classification model based on the abundance of three species, Haemophilus parainfluenzae, Roseburia inulinivorans, and Roseburia hominis, performed well for discriminating between healthy and diseased patients. Additionally, the healthy and diseased states can be distinguished by SNPs in the species of B. vulgatus. We present a comprehensive profile of changes in the microbiota in clinical TB patients. Our findings will shed light on the design of future diagnoses and treatments for M. tuberculosis infections
Treating tuberculosis with high doses of anti-TB drugs: mechanisms and outcomes
Abstract Tuberculosis (TB) is considered as one of the most serious threats to public health in many parts of the world. The threat is even more severe in the developing countries where there is a lack of advanced medical amenities and contemporary anti-TB drugs. In such situations, dosage optimization of existing medication regimens seems to be the only viable option. Therapeutic drug monitoring study results suggest that high-dose treatment regimens can compensate the low serum concentration of anti-TB drugs and shorten the therapy duration. The article presents a critical review on the possible changes that occur in the host and the pathogen upon the administration of standard and high-dose regimens. Some of the most common factors that are responsible for low anti-TB drug concentrations in the serum are differences in hosts’ body weight, metabolic processing of the drug, malabsorption and/or drug–drug interaction. Furthermore, failure to reach the cavitary pulmonary and extrapulmonary tissues also contributes to the therapeutic inefficiency of the drugs. In such conditions, administration of higher doses can help in compensating the pathogenic outcomes of enhancement of the pathogen’s physical barriers, efflux pumps and genetic mutations. The present article also presents a summary of the recorded treatment outcomes of clinical trials that were conducted to test the efficacy of administration of high dose of anti-tuberculosis drugs. This review will help physicians across the globe to understand the underlying pathophysiological changes (including side effects) that dictate the clinical outcomes in patients administered with standard and/or high dose anti-TB drugs
Influence of Glyceryl Monostearate Adsorption on the Lubrication Behavior of a Slider Bearing
Glyceryl monostearate (GMS) was used as an organic friction modifier (OFM) and added to the base oil (PAO10, polyα-olefin) in this study. The film thickness and friction coefficient of the base oil added with GMS (PAO10G) under different slider inclinations and loads were investigated experimentally by using a slider-on-disc contact lubricant film measurement system, and the effect of the adsorption of GMS on the friction behavior of lubricant was studied. Contact angle hysteresis (CAH) was used to evaluate the wettability of the solid–liquid interface, and its correlation with the coefficient of friction was analyzed. The results show that CAH is in good agreement with the wettability of the solid–liquid interface. Compared with the base oil, the wettability of POA10G is weak, which can effectively reduce the coefficient of friction. However, different from the classical lubrication theory, the film thickness of PAO10G is higher than that of PAO10; this unusual phenomenon is preliminarily explained by the interface slippage in this paper
Using the Multidimensional Health Locus of Control Scale Form C to Investigate Health Beliefs About Bladder Cancer Prevention and Treatment Among Male Patients: Cross-Sectional Study
BackgroundBladder cancer is a leading cause of death among Chinese male populations in recent years. The health locus of control construct can mediate health status and outcomes, and it has proven helpful in predicting and explaining specific health-related behaviors. However, it has never been used to investigate health beliefs about bladder cancer prevention and treatment.
ObjectiveThis study aimed to classify male patients into different latent groups according to their beliefs about bladder cancer prevention and treatment and to identify associated factors to provide implications for the delivery of tailored education and interventions and the administration of targeted prevention and treatment.
MethodsFirst, we designed a four-section questionnaire to solicit data: section 1—age, gender, and education; section 2—the communicative subscale of the All Aspects of Health Literacy Scale; section 3—the eHealth Literacy Scale; and section 4—health beliefs about bladder cancer prevention and treatment measured by the Multidimensional Health Locus of Control Scale Form C. We hypothesized that the participants’ health beliefs about bladder cancer prevention and treatment measured in section 4 could be closely associated with information collected through sections 1 to 3. We recruited 718 Chinese male patients from Qilu Hospital of Shandong University, China, and invited them to participate in a web-based questionnaire survey. Finally, we used latent class analysis to identify subgroups of men based on their categorical responses to the items on the Multidimensional Health Locus of Control Scale Form C and ascertained factors contributing to the low self-efficacy group identified.
ResultsWe identified 2 subgroups defined as low and moderate self-efficacy groups representing 75.8% (544/718) and 24.2% (174/718) of the total sample, respectively. Men in the low self-efficacy cluster (cluster 1: 544/718, 75.8%) were less likely to believe in their own capability or doctors’ advice to achieve optimal outcomes in bladder cancer prevention and treatment. Men in the moderate self-efficacy cluster (cluster 2: 174/718, 24.2%) had distinct psychological traits. They had stronger beliefs in their own capability to manage their health with regard to bladder cancer prevention and treatment and moderate to high levels of trust in health and medical professionals and their advice to achieve better prevention and treatment outcomes. Four factors contributing to low self-efficacy were identified, including limited education (Year 6 to Year 12), aged ≥44 years, limited communicative health literacy, and limited digital health literacy.
ConclusionsThis was the first study investigating beliefs about bladder cancer prevention and treatment among Chinese male patients. Given that bladder cancer represents a leading cause of death among Chinese male populations in recent years, the low self-efficacy cluster and associated contributing factors identified in this study can provide implications for clinical practice, health education, medical research, and health policy-making
Functional Health Literacy Among Chinese Populations and Associated Factors: Latent Class Analysis
BackgroundPoor functional health literacy has been found to be independently associated with poor self-assessed health, poor understanding of one’s health condition and its management, and higher use of health services. Given the importance of functional health literacy, it is necessary to assess the overall status of functional health literacy in the general public. However, the literature review shows that no studies of functional health literacy have been conducted among the Chinese population in China.
ObjectiveThis study aimed to classify Chinese populations into different functional health literacy clusters and ascertain significant factors closely associated with low functional health literacy to provide some implications for health education, medical research, and public health policy making.
MethodsWe hypothesized that the participants’ functional health literacy levels were associated with various demographic characteristics. Therefore, we designed a four-section questionnaire including the following information: (1) age, gender, and education; (2) self-assessed disease knowledge; (3) 3 validated health literacy assessment tools (ie, the All Aspects of Health Literacy Scale, the eHealth Literacy Scale, and the 6-item General Health Numeracy Test); and (4) health beliefs and self-confidence measured by the Multidimensional Health Locus of Control Scales Form B. Using randomized sampling, we recruited survey participants from Qilu Hospital affiliated to Shandong University, China. The questionnaire was administered via wenjuanxing. A returned questionnaire was valid only when all question items included were answered, according to our predefined validation criterion. All valid data were coded according to the predefined coding schemes of Likert scales with different point (score) ranges. Finally, we used latent class analysis to classify Chinese populations into clusters of different functional health literacy and identify significant factors closely associated with low functional health literacy.
ResultsAll data in the 800 returned questionnaires proved valid according to the predefined validation criterion. Applying latent class analysis, we classified Chinese populations into low (n=292, 36.5%), moderate-to-adequate (n=286, 35.7%), and low-to-moderate (n=222, 27.8%) functional health literacy groups and identified five factors associated with low communicative health literacy: (1) male gender (aged 40-49 years), (2) lower educational attainment (below diploma), (3) age between 38 and 68 years, (4) lower self-efficacy, and (5) belief that staying healthy was a matter of luck.
ConclusionsWe classified Chinese populations into 3 functional health literacy groups and identified 5 factors associated with low functional health literacy. These associated factors can provide some implications for health education, medical research, and health policy making
Factors Associated With Limited Digital Health Literacy Among Chinese Male Populations: Cross-sectional Study
BackgroundeHealth resources and interventions promise to promote favorable behavior change, self-efficacy, and knowledge acquisition, thereby improving health literacy. However, individuals with limited eHealth literacy may find it difficult to identify, understand, and benefit from eHealth use. It is necessary to identify the self-assessed eHealth literacy of those who use eHealth resources to classify their eHealth literacy levels and to determine the demographic characteristics associated with higher and lower eHealth literacy skills.
ObjectiveThis study aimed to identify notable factors closely associated with limited eHealth literacy among Chinese male populations to provide some implications for clinical practice, health education, medical research, and public health policy making.
MethodsWe hypothesized that participants’ eHealth literacy status was associated with various demographic characteristics. Therefore, we elicited the following information in the questionnaire: age and education, self-assessed disease knowledge, 3 well-developed health literacy assessment tools (ie, the All Aspects of Health Literacy Scale, eHealth Literacy Scale, and General Health Numeracy Test), and the 6 Internal items on health beliefs and self-confidence in the Multidimensional Health Locus of Control Scales. Using randomized sampling, we recruited survey participants from Qilu Hospital of Shandong University, China. After validating the data collected through a web-based questionnaire survey via wenjuanxing, we coded all valid data according to predefined coding schemes of Likert scales with different point (score) ranges. We then calculated the total scores of the subsections of the scales or the entire scale. Finally, we used logistic regression modeling to associate the scores of the eHealth Literacy Scale with the scores of the All Aspects of Health Literacy Scale, the General Health Numeracy Test-6, and age and education to ascertain factors considerably associated with limited eHealth literacy among Chinese male populations.
ResultsAll data from the 543 returned questionnaires were valid according to the validation criteria. By interpreting these descriptive statistics, we found that 4 factors were significantly correlated with participants’ limited eHealth literacy: older age, lower education attainment, lower levels of all aspects of health literacy (functional, communicative, and critical), and weaker beliefs and self-confidence in internal drivers and strengths to stay healthy.
ConclusionsBy applying logistic regression modeling, we ascertained 4 factors that were significantly correlated with limited eHealth literacy among Chinese male populations. These relevant factors identified can inform stakeholders engaging in clinical practice, health education, medical research, and health policy making
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