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1.
The deterministic and probabilistic prediction of ship motion is important for safe navigation and stable real-time operational control of ships at sea. However, the volatility and randomness of ship motion, the non-adaptive nature of single predictors and the poor coverage of quantile regression pose serious challenges to uncertainty prediction, making research in this field limited. In this paper, a multi-predictor integration model based on hybrid data preprocessing, reinforcement learning and improved quantile regression neural network (QRNN) is proposed to explore the deterministic and probabilistic prediction of ship pitch motion. To validate the performance of the proposed multi-predictor integrated prediction model, an experimental study is conducted with three sets of actual ship longitudinal motions during sea trials in the South China Sea. The experimental results indicate that the root mean square errors (RMSEs) of the proposed model of deterministic prediction are 0.0254°, 0.0359°, and 0.0188°, respectively. Taking series #2 as an example, the prediction interval coverage probabilities (PICPs) of the proposed model of probability predictions at 90%, 95%, and 99% confidence levels (CLs) are 0.9400, 0.9800, and 1.0000, respectively. This study signifies that the proposed model can provide trusted deterministic predictions and can effectively quantify the uncertainty of ship pitch motion, which has the potential to provide practical support for ship early warning systems. 相似文献
2.
随着人脸识别技术的不断进步以及人脸卡口的大范围且密集的部署, 本文针对团伙犯罪案件侦察这一应用场景, 对人脸卡口数据进行深入挖掘, 探究其中行人间的共现关系, 获取所关注的嫌疑人的现实社交网络, 锁定团伙其余人员. 经过实验比对和论证, 本文使用Chinese Whispers聚类算法对行人节点进行识别, 通过Faiss加速邻接边的构建, 加速图的初始化步骤, 解决其聚类效率低下的问题. 在此基础上, 使用共现频次和Apriori算法中的置信度挖掘行人间的共现关系, 构建行人共现关系图谱. 相似文献
3.
IntroductionThe main purpose of this cross-sectional study was to investigate whether visual discomfort acts as a mediating factor between perceived visual ergonomic working conditions and self-rated visual performance among office workers who carry out administrative tasks and computer-based work at the Swedish Tax Agency.MethodsA questionnaire was sent to 94 office workers addressing: 1) perceived visual quality of the visual display units; 2) prevalence of eye symptoms; and 3) self-rated visual performance. Eighty-six persons (54 women (63%), 31 men (36%), and 1 of unspecified sex) answered the questionnaire. Multiple regression analysis investigated the association between visual ergonomic working conditions and visual performance, both with and without visual discomfort as a mediator.ResultsThe group mean of the Indexed survey questions indicated a reasonably good quality of visual ergonomic working conditions, a relative absence of eye symptoms, and acceptable self-rated visual performance. Results from multiple regression analysis showed a significant association between perceived visual ergonomic working conditions and self-rated visual performance (r2 = 0.30, β = 0.327, p < 0.01). When visual discomfort was used as a mediator, the association between perceived visual ergonomic working conditions and self-rated visual performance remained the same (r2 = 0.32, β = 0.315, p < 0.01).DiscussionIt was remarkable to discover that self-rated visual performance was independent of visual discomfort. Possible explanations include exposure factors not included in the current study, such as dry air and sensory irritation in the eyes, psychosocial stress, time spent performing near work activities, or time exposed to visually deficient working conditions.Relevance to industryThe strong connection between satisfaction with visual ergonomic working conditions and productivity in this study has implications for workplace profitability and staff satisfaction. If productivity is enhanced by better visual ergonomic working conditions, then managers of workplaces may be able to improve work outcomes by optimizing the physical work environment. 相似文献
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5.
《Journal of dairy science》2019,102(10):8807-8818
A series of food safety incidents related to domestically produced dairy in China harmed consumer confidence and caused a dramatic decrease in dairy consumption from 2008 to 2010. Compared with previous studies that mainly assessed consumer confidence in food or dairy in general, this study focused on 2 specific dairy products, milk and infant milk formula (IMF). Based on data from 934 Chinese consumers, confidence in the safety of milk and IMF was measured by using a multi-item scale with 2 dimensions—optimism and pessimism. We found that Chinese consumers were optimistic about the safety of milk and IMF but, at the same time, were concerned about the risks related to milk and IMF. Chinese consumers have less confidence in IMF than in milk. Structural equation modeling indicated that consumer trust in manufacturers and third parties in the dairy supply chain and confidence in other foods, such as meat and fish, can foster consumer confidence in the safety of milk and IMF, while the extent of recall of the melamine infant formula incident in 2008 and trait worry exert negative effects. In addition, consumers with more children or less family income are likely to be more confident in domestically produced IMF. These insights into consumer confidence and its determinants can assist dairy supply chains and regulatory institutions in formulating effective risk communication strategies to strengthen consumer confidence. 相似文献
6.
For the United States Nuclear Regulatory Commission and the reactor licensees it regulates, there are a number of contemporary issues associated with the back end of the fuel cycle including, the agency's revision to its “Waste Confidence” decision and the path-forward for high-level waste disposal. Additionally, the 2012 Blue Ribbon Commission on America's Nuclear Future recommendations, the future of reprocessing, consolidated interim spent fuel storage, and maintaining technical competence within the NRC in challenging budgetary conditions are addressed. I conclude that there is confidence in the feasibility of safe storage of spent nuclear fuel following the licensed operational life of a reactor and any change in high-level waste policy will require Congressional action to amend the Nuclear Waste Policy Act. 相似文献
7.
Yuming Guo Shilu Tong Adrian G. Barnett Xiaochuan Pan 《The Science of the total environment》2010,408(20):4446-1817
Background
A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension.Objective
To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China.Methods
We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5), particulate matter less than 10 μm in aerodynamic diameter (PM10), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models.Results
There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10 μg/m3 in PM2.5 and PM10 was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively.Conclusion
Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China. 相似文献8.
建筑结构概率可靠度的区间估计 总被引:1,自引:0,他引:1
介绍了正态分布强度参数未知、正态分布应力和强度参数均未知,同时考虑4个随机变量、取可靠度指标β为正态分布等几种常见情况下可靠度置信区间的确定方法,以达到在理论上补充和完善可靠度理论的目的。 相似文献
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10.
Sub-micrometer particulate air pollution and cardiovascular mortality in Beijing, China 总被引:1,自引:0,他引:1
Breitner S Liu L Cyrys J Brüske I Franck U Schlink U Leitte AM Herbarth O Wiedensohler A Wehner B Hu M Pan XC Wichmann HE Peters A 《The Science of the total environment》2011,409(24):5196-5204