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正常青年不同体位牙尖交错位接触的研究 被引量:3
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作者 林珍香 陈润 +2 位作者 林捷 潘在兴 程辉 《广东牙病防治》 2015年第9期465-468,共4页
目的研究正常青年在端坐位、45°斜躺位及平躺位时牙尖交错位的接触情况。方法应用T-scanⅢ数字化咬合分析系统记录135名正常青年3种体位的接触过程。结果 3种体位时最初接触帧接触点(χ2=0.074,P=0.963)和最大感应面积帧... 目的研究正常青年在端坐位、45°斜躺位及平躺位时牙尖交错位的接触情况。方法应用T-scanⅢ数字化咬合分析系统记录135名正常青年3种体位的接触过程。结果 3种体位时最初接触帧接触点(χ2=0.074,P=0.963)和最大感应面积帧力值最大点(χ2=0.071,P=0.965)差异均无统计学意义。不同牙位的最大感应面积帧差异具有统计学意义(χ2=42.729,P<0.001),其中磨牙区接触频数最高。结论最初接触的牙位与体位之间无明显关系;最大感应面积帧力值最大点集中在磨牙区,而前牙和前磨牙区域较少。 展开更多
关键词 牙尖交错位 体位 最初接触帧 最大感应面积帧
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Spatial Transferability of Vegetation Types in Distribution Models Based on Sample Surveys from an Alpine Region
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作者 Linda Aune-Lundberg Anders Bryn 《Journal of Geographic Information System》 2018年第1期111-141,共31页
Vegetation mapping using field surveys is expensive. Distribution modelling, based on sample surveys, might overcome this challenge. We tested if models trained from sample surveys could be used to predict the distrib... Vegetation mapping using field surveys is expensive. Distribution modelling, based on sample surveys, might overcome this challenge. We tested if models trained from sample surveys could be used to predict the distribution of vegetation types in neighbourhood areas, and how reliable the spatial transferability was. We also tested whether we should use ecological dissimilarity or spatial distance to foresee modelling performance. Maximum entropy models were run for three vegetation types based on a vegetation map within a mountain range. Environmental variables were selected backwards, model complexity was kept low. The models are based on points from a small part of each study site, transferred into the entire sites, and then tested for performance. Environmental distance was tested using principle component analysis. All models had high uncorrected AUC values. The ability to predict presences correctly was low. The ability to predict absences correctly was high. The ability to transfer the distribution model depended on environmental distance, not spatial distance. 展开更多
关键词 area frame Survey ECOLOGICAL Distance GIS INDEPENDENT Evaluation Data maximum ENTROPY Modelling VEGETATION Mapping
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