Link quality prediction based on random forest

Link quality prediction is vital to the upper layer protocol design of wireless sensor networks.Selecting high quality links with the help of link quality prediction mechanisms can improve data transmission reliability and network communication efficiency.The Gaussian mixture model algorithm based on unsupervised clustering was employed to divide the link quality level.Zero-phase component analysis (ZCA) whitening was applied to remove the correlation between samples.The mean and variance of signal to noise ratio,link quality indicator,and received signal strength indicator were taken as the estimation parameters of link quality,and a link quality estimation model was constructed by using a random forest classification algorithm.The random forest regression algorithm was used to build a link quality prediction model,which predicted the link quality level at the next moment.In different scenarios,comparing with exponentially weighted moving average,triangle metric,support vector regression and linear regression prediction models,the proposed prediction model has higher prediction accuracy

Reflectance and Carbon Isotopes of Kerogen in Lower Cambrian Black Shales of Zunyi and Zhangjiajie, Southwest China : Indicators to the Source of Au-Ag-PGE

China University of GeosciencesInstitute of Geochemistry, Academia SinicaScedule:17-18 March 2003, Vemue: Kanazawa, Japan, Kanazawa Citymonde Hotel, Project Leader : Hayakawa, Kazuichi, Symposium Secretariat: XO kamata, Naoto, Edited by:Kamata, Naoto

Thermoluminescence (TL) analysis for otoliths of the wild carps (cyprinoid) from Baiyangdian Lake and Miyun Reservoir: Some implications for monitoring water environment

Otolith is a typical biomineral carrier growing on insides of fish skull with prominent zoning structure formed by alternating layers of protein and calcium carbonate growing around the nucleus. Even though thermoluminescence (TL) analysis on biomineral has been widely used to measure the radiation exposure in the recent twenty years, the TL characteristics of the fish otolith have not yet been reported in literature. TL characteristics of otoliths from the wild carps (cyprinoid) living in the Baiyangdian Lake, Hebei Province and Miyun Reservoir, Beijing City was first studied, and the differences of energy gap (E) between the fish otoliths in the two waters have also been discussed in this paper. The experimental results indicated that TL curve parameters: peak temperature (Tp), luminous intensity (I), integrated intensity (S) and middle width (Wm) for the glow curves of the cyprinoid otoliths from Baiyangdian Lake are greater than those from Miyun reservoir, and the stability of the formers’ TL curve parameters value and energy gap (E) was weaker than the latter. In comparison to the Miyun Reservoir, the analysis manifested that the electrons and vacancies trapped in the otoliths from Baiyangdian Lake are more likely to escape. According to the investigation, the contaminative degree and eutrophication in the water of Baiyangdian Lake was heavier than that of Miyun Reservoir. Therefore, the characteristics of TL growth curves of the cyprinoid otoliths is quite sensitive to heavier contaminated and less contaminated water, and this could be regarded as an important typomorphic biomineral for monitoring the contaminative degree and environment change of the water.Keywords: Cyprinoid otoliths, thermoluminescence, water environment, typomorphic minera

Advanced age is associated with increased adverse outcomes in patients undergoing middle cerebral artery stenting

PurposeThis study tried to evaluate whether advanced age has an increased incidence of major complications in patients undergoing MCA stenting.MethodsA total of 348 patients who underwent MCA stenting were reviewed from a prospectively maintained database. Ninety-day ischemic stroke, intracerebral hemorrhage, and death outcomes were compared among the young (≤40 years old), middle (41–60 years old) and old (≥61 years old) groups. Univariate analysis and multivariable logistic regression analysis were used to investigate different variables associated with 90-day major adverse events. Kaplan–Meier analysis was performed to determine long-term outcomes during follow-up.ResultsThe incidence of 90-day ischemic stroke was 9.26% in the old group, 2.86% in the middle group, and 0% in the young group (P = 0.024). The incidence of all 90-day major adverse events was 3.33% in patients ≤40 years old, 19.90% in patients 41–60 years old, and 24.07% in patients ≥61 years old, with statistical significance (P = 0.04). Advanced age was associated with increased 90-day ischemic stroke (OR = 1.074, 95% CI: 1.019–1.132, P = 0.007; adjusted OR: 1.071, 95% CI: 1.008–1.138, P = 0.026) and 90-day death (OR = 1.072, 95% CI: 1.012–1.135, P = 0.018; adjusted OR: 1.095, 95% CI: 1.015–1.182, P = 0.018). Meanwhile, advanced age was also associated with decreased long-term survival and ischemic stroke-free survival during follow-up.ConclusionOur data indicated that MCA stenting in elderly patients is associated with a high risk of adverse events and should be cautiously considered

Environment, technology and sustainability: the development and management of well-irrigation in Guanzhong Plain in Qing China

This paper presents a case study of the well irrigation in Guanzhong Plain during the Qing dynasty. The paper analyses the scales and results of well irrigation campaigns sponsored by the government in the mid-eighteen century and the late nineteenth century. Limited by the natural environment and technical conditions, the eficiency of well irrigation is poor. Farmers' choices also afect the development of well irrigation. Moreover, a lack of management led to the unsustainable use of groundwater. Historical groundwater policies were mainly aimed at increasing agricultural production. Policies should be made according to local conditions. It is important to ensure the sustainable development of groundwater

Environment, technology and sustainability: the development and management of well-irrigation in Guanzhong Plain in Qing China

This paper presents a case study of the well irrigation in Guanzhong Plain during the Qing dynasty. The paper analyses the scales and results of well irrigation campaigns sponsored by the government in the mid-eighteen century and the late nineteenth century. Limited by the natural environment and technical conditions, the efficiency of well irrigation is poor. Farmers’ choices also affect the development of well irrigation. Moreover, a lack of management led to the unsustainable use of groundwater. Historical groundwater policies were mainly aimed at increasing agricultural production. Policies should be made according to local conditions. It is important to ensure the sustainable development of groundwater