In this paper we propose a method to construct probability measures on the space of convex bodies. For this purpose, first, we introduce the notion of thinness of a body. Then we show the existence of a measure with t...In this paper we propose a method to construct probability measures on the space of convex bodies. For this purpose, first, we introduce the notion of thinness of a body. Then we show the existence of a measure with the property that its pushforward by the thinness function is a probability measure of truncated normal distribution. Finally, we improve this method to find a measure satisfying some important properties in geometric measure theory.展开更多
A binary gravitational rotator, also called the two-body problem, is a pair of masses m<sub>1</sub>, m<sub>2</sub> moving around their center-of-mass (com) in their own gravitational field. In ...A binary gravitational rotator, also called the two-body problem, is a pair of masses m<sub>1</sub>, m<sub>2</sub> moving around their center-of-mass (com) in their own gravitational field. In Newtonian gravitation, the two-body problem can be described by a single reduced mass (gravitational rotator) m<sub>r</sub> = m<sub>1</sub>m<sub>2</sub>/(m<sub>1</sub>+m<sub>2</sub>) orbiting around the total mass m = m<sub>1</sub>+m<sub>2</sub> situated in com in the distance r, which is the distance between the two original masses. In this paper, we discuss the rotator in Newtonian, Schwarzschild and Kerr spacetime context. We formulate the corresponding Kerr orbit equations, and adapt the Kerr rotational parameter to the Newtonian correction of the rotator potential. We present a vacuum solution of Einstein equations (Manko-Ruiz), which is a generalized Kerr spacetime with five parameters g<sub>μν</sub> (m<sub>1</sub>, m<sub>2</sub>, R, a<sub>1</sub>, a<sub>2</sub>), and adapt it to the Newtonian correction for observer orbits. We show that the Manko-Ruiz metric is the exact solution of the GR-two-body problem (i.e. GR-rotator) and express the orbit energy and angular momentum in terms of the 5 parameters. We calculate and discuss Manko-Ruiz rotator orbits in their own field, and present numerical results for two examples. Finally, we carry out numerical calculations of observer orbits in the rotator field for all involved models and compare them.展开更多
明确能有效鉴定区分啮齿动物近似种的体型和头骨特征指标,有利于因地制宜地快速、准确鉴定近似种。我们利用一段725 bp Vkorc1基因序列鉴定了36只同域分布的褐家鼠(Rattus norvegicus)(n=31)和黄胸鼠(Rattus tanezumi)(n=5)个体,随后分...明确能有效鉴定区分啮齿动物近似种的体型和头骨特征指标,有利于因地制宜地快速、准确鉴定近似种。我们利用一段725 bp Vkorc1基因序列鉴定了36只同域分布的褐家鼠(Rattus norvegicus)(n=31)和黄胸鼠(Rattus tanezumi)(n=5)个体,随后分别就这些样本的胴体重、体长、尾长、耳长和后足长及尾长/体长、耳长/体长、后足长/体长和肥满度等指标的21种指标组,及10只褐家鼠和3只黄胸鼠的2种头骨指标组进行了主成分分析及聚类分析,比较了这些指标组对两物种的分类鉴定结果。结果显示,尾长/体长、耳长/体长和肥满度指标组,及上颊齿列基长、下颊齿列基长、听泡长和听泡宽指标组可将两物种完全区分开。结果为使用体型或头骨指标准确鉴定区分这两物种提供了清晰依据和可靠分析手段。展开更多
Existing mobility models have limitations in their ability to simulate the movement of Wireless Body Area Network（WBAN） since body nodes do not exactly follow either classic mobility models or human contact distribu...Existing mobility models have limitations in their ability to simulate the movement of Wireless Body Area Network（WBAN） since body nodes do not exactly follow either classic mobility models or human contact distributions. In this paper, we propose a new mobility model called Body Gauss–Markov Mobility（BGMM） model,which is oriented specially to WBAN. First, we present the random Gauss-Markov mobility model as the most suitable theoretical basis for developing our new model, as its movement pattern can reveal real human body movements. Next, we examine the transfer of human movement states and derive a simplified mathematical Human Mobility Model（HMM）. We then construct the BGMM model by combining the RGMM and HMM models. Finally,we simulate the traces of the new mobility model. We use four direct metrics in our proposed mobility model to evaluate its performance. The simulation results show that the proposed BGMM model performs with respect to the direct mobility metrics and can effectively represent a general WBAN-nodes movement pattern.展开更多
Long-term and large-scale lake statistics are meaningful for the study of environment change,but many of the existing methods are labourintensive and time-consuming.To overcome this problem,a novel method for long-te...Long-term and large-scale lake statistics are meaningful for the study of environment change,but many of the existing methods are labourintensive and time-consuming.To overcome this problem,a novel method for long-term and large-scale lake extraction by shape-factorsand machine-learning-based water body classification is proposed.An experiment was conducted to extract the lakes in the Yangtze River basin(YRB)from 2008 to 2018 with the Joint Research Centre’s Global Surface Water Dataset(JRC GSW)data and OSM data.The results show:1)The proposed method is automatically and successfully executed.2)The number of river–lake complexes is between 3008 and 4697,representing 3.56%–5.70%of the total water bodies.3)The areas of the lakes and rivers in the YRB were obtained,and the accuracy of water classification in each year was stable between 90.2%and 93.6%.Comparing the back propagation neural network,random forest,and support vector machine models,we found that the three machine learning models have similar classification accuracy for the scenario.4)Fragmented and incomplete small rivers in the JRC GSW data,unchecked training samples,and overlapped shape factors are the three error sources.Future work will focus on addressing these three error sources.展开更多
A select group of Sales and Marketing Leaders from the hospitality industry. speaking at the inaugural HSMAI Asia Pacific Thought Leaders in Marketing Roundtable in Singapore. called for a review of Asian Hospitality ...A select group of Sales and Marketing Leaders from the hospitality industry. speaking at the inaugural HSMAI Asia Pacific Thought Leaders in Marketing Roundtable in Singapore. called for a review of Asian Hospitality practices as well as a body to take charge of the issue of standardizing services. metrics and ratings for the industry.展开更多
文摘In this paper we propose a method to construct probability measures on the space of convex bodies. For this purpose, first, we introduce the notion of thinness of a body. Then we show the existence of a measure with the property that its pushforward by the thinness function is a probability measure of truncated normal distribution. Finally, we improve this method to find a measure satisfying some important properties in geometric measure theory.
文摘A binary gravitational rotator, also called the two-body problem, is a pair of masses m<sub>1</sub>, m<sub>2</sub> moving around their center-of-mass (com) in their own gravitational field. In Newtonian gravitation, the two-body problem can be described by a single reduced mass (gravitational rotator) m<sub>r</sub> = m<sub>1</sub>m<sub>2</sub>/(m<sub>1</sub>+m<sub>2</sub>) orbiting around the total mass m = m<sub>1</sub>+m<sub>2</sub> situated in com in the distance r, which is the distance between the two original masses. In this paper, we discuss the rotator in Newtonian, Schwarzschild and Kerr spacetime context. We formulate the corresponding Kerr orbit equations, and adapt the Kerr rotational parameter to the Newtonian correction of the rotator potential. We present a vacuum solution of Einstein equations (Manko-Ruiz), which is a generalized Kerr spacetime with five parameters g<sub>μν</sub> (m<sub>1</sub>, m<sub>2</sub>, R, a<sub>1</sub>, a<sub>2</sub>), and adapt it to the Newtonian correction for observer orbits. We show that the Manko-Ruiz metric is the exact solution of the GR-two-body problem (i.e. GR-rotator) and express the orbit energy and angular momentum in terms of the 5 parameters. We calculate and discuss Manko-Ruiz rotator orbits in their own field, and present numerical results for two examples. Finally, we carry out numerical calculations of observer orbits in the rotator field for all involved models and compare them.
文摘明确能有效鉴定区分啮齿动物近似种的体型和头骨特征指标,有利于因地制宜地快速、准确鉴定近似种。我们利用一段725 bp Vkorc1基因序列鉴定了36只同域分布的褐家鼠(Rattus norvegicus)(n=31)和黄胸鼠(Rattus tanezumi)(n=5)个体,随后分别就这些样本的胴体重、体长、尾长、耳长和后足长及尾长/体长、耳长/体长、后足长/体长和肥满度等指标的21种指标组,及10只褐家鼠和3只黄胸鼠的2种头骨指标组进行了主成分分析及聚类分析,比较了这些指标组对两物种的分类鉴定结果。结果显示,尾长/体长、耳长/体长和肥满度指标组,及上颊齿列基长、下颊齿列基长、听泡长和听泡宽指标组可将两物种完全区分开。结果为使用体型或头骨指标准确鉴定区分这两物种提供了清晰依据和可靠分析手段。
基金supported by the National Natural Science Foundation of China(Nos.61171107 and 61271257)General program of science and technology development project of Beijing Municipal Education Commission(Nos.KM201510012005,SQKM201610012008,and SQKM201710012006)+1 种基金the research project of the China Scholarship Council(Nos.201509970037 and 201609970003)Beijing Institute of Fashion Technology College of Special Plan Young Top-notch Talent Project(No.BIFTBJ201803)
文摘Existing mobility models have limitations in their ability to simulate the movement of Wireless Body Area Network（WBAN） since body nodes do not exactly follow either classic mobility models or human contact distributions. In this paper, we propose a new mobility model called Body Gauss–Markov Mobility（BGMM） model,which is oriented specially to WBAN. First, we present the random Gauss-Markov mobility model as the most suitable theoretical basis for developing our new model, as its movement pattern can reveal real human body movements. Next, we examine the transfer of human movement states and derive a simplified mathematical Human Mobility Model（HMM）. We then construct the BGMM model by combining the RGMM and HMM models. Finally,we simulate the traces of the new mobility model. We use four direct metrics in our proposed mobility model to evaluate its performance. The simulation results show that the proposed BGMM model performs with respect to the direct mobility metrics and can effectively represent a general WBAN-nodes movement pattern.
基金supported by the National Nature Science Foundation of China(nos.41971351,41771422,41890822).
文摘Long-term and large-scale lake statistics are meaningful for the study of environment change,but many of the existing methods are labourintensive and time-consuming.To overcome this problem,a novel method for long-term and large-scale lake extraction by shape-factorsand machine-learning-based water body classification is proposed.An experiment was conducted to extract the lakes in the Yangtze River basin(YRB)from 2008 to 2018 with the Joint Research Centre’s Global Surface Water Dataset(JRC GSW)data and OSM data.The results show:1)The proposed method is automatically and successfully executed.2)The number of river–lake complexes is between 3008 and 4697,representing 3.56%–5.70%of the total water bodies.3)The areas of the lakes and rivers in the YRB were obtained,and the accuracy of water classification in each year was stable between 90.2%and 93.6%.Comparing the back propagation neural network,random forest,and support vector machine models,we found that the three machine learning models have similar classification accuracy for the scenario.4)Fragmented and incomplete small rivers in the JRC GSW data,unchecked training samples,and overlapped shape factors are the three error sources.Future work will focus on addressing these three error sources.
文摘A select group of Sales and Marketing Leaders from the hospitality industry. speaking at the inaugural HSMAI Asia Pacific Thought Leaders in Marketing Roundtable in Singapore. called for a review of Asian Hospitality practices as well as a body to take charge of the issue of standardizing services. metrics and ratings for the industry.
