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spatial point pattern analysis of traffic violations in Luzhou City, China

TRANSPORTATION LETTERS-THE INTERNATIONAL JOURNAL OF TRANSPORTATION RESEARCH 2022年第10期14卷 1162-1171页

作者： Atumo, Eskindir Ayele Jiang, Xinguo Fu, Chuanyun Southwest Jiaotong Univ Sch Transportat & Logist Chengdu Peoples R China Dire Dawa Univ Dire Dawa Inst Technol Dire Dawa Ethiopia Southwest Jiaotong Univ Natl United Engn Lab Integrated & Intelligent Tra Chengdu Peoples R China Southwest Jiaotong Univ Natl Engn Lab Integrated Transportat Big Data App Chengdu Peoples R China Fujian Univ Technol Sch Transportat Fuzhou Peoples R China Harbin Inst Technol Dept Transportat Engn Sch Transportat Sci & Engn Harbin Peoples R China

The study presents spatial analysis of traffic violations in Luzhou city, China. Three metrics of spatial point pattern, namely intensity, spatial correlation, and spacing, are evaluated using (i) kernel density and quadrant count;(ii) K and L functions;and (iii) nearest neighbor and empty-space distance methods, respectively. The results show that: (i) three specific places have a high rate of illegal turning movements, disobeying prohibited signs, and illegal parking violations;(ii) all the violation categories have hot spots, among which 53.49% of the total appear at nine different places;(iii) the spatial correlation discloses the existence of spatial dependence and closeness of similar violations;and (iv) the spacing between traffic violations also signifies clustering of violations. Generally, the spatial patterns of traffic violations are nonuniform, have identifiable hot spots, and are clustered. The findings are beneficial for conceiving safety treatment strategies against traffic violations and additional relevant clustering studies.

关键词： spatial point pattern traffic violations poisson point process homogeneous point process inhomogeneous point process

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Effect of Quadrat Shape on spatial point pattern Performance of Haloxylon ammodendron

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Open Journal of Ecology 2024年第1期14卷 66-76页

作者： Shaohua Wang Longwei Dai College of Economics and Management Hunan University of Arts and Science Changde China

In this study, we investigated the natural growth of Haloxylon ammodendron forest in Moso Bay, southwest of Gurbantunggut Desert. Random sample analysis was used to analyze the spatial point pattern performance of Haloxylon ammodendron population. ArcGIS software was used to summarize and analyze the spatial point pattern response of Haloxylon ammodendron population. The results showed that: 1) There were significant differences in the performance of point pattern analysis among different random quadrants. The paired t-test for variance mean ratio showed that the P values were 0.048, 0.004 and 0.301 respectively, indicating that the influence of quadrat shape on the performance of point pattern analysis was significant under the condition of the same optimal quadrat area. 2) The comparative analysis of square shapes shows that circular square is the best, square and regular hexagonal square are the second, and there is no significant difference between square and regular hexagonal square. 3) The number of samples plays a decisive role in spatial point pattern analysis. Insufficient sample size will lead to unstable results. With the increase of the number of samples to more than 120, the V value and P value curves will eventually stabilize. That is, stable spatial point pattern analysis results are closely related to the increase of the number of samples in random sample square analysis.

关键词： spatial point pattern Random Quadrat Quadrat Analysis Quadrat Shape

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Analysis of spatial point patterns in electron-counting images

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MICROSCOPY 2022年第3期71卷 142-151页

作者： Kodama, Tetsuji Nakashima, Yusuke Akashi, Tetsuya Takahashi, Yoshio Mori, Shigeo Harada, Ken Meijo Univ Fac Sci & Technol Nagoya Aichi 4688502 Japan Hitachi Ltd Res & Dev Grp Hatoyama Saitama 3500395 Japan Osaka Prefecture Univ Dept Mat Sci Sakai Osaka 5998531 Japan RIKEN CEMS Inst Phys & Chem Res Hatoyama Saitama 3500395 Japan

In this study, the spatial counting statistics of free electron beams, which were released via field emission from cold metal and propagated through a vacuum region, were investigated to examine the normal functioning of the counting equipment for electron correlation spectroscopy. The beam electrons were recorded separately according to the locations of individual events as they reached the direct detection transmission Complementary Metal Oxide Semiconductor (CMOS) sensor. We examined the spatial point patterns arising from the locations of the individual events of each primary electron being detected in the case of electrons in a state in which the wave function is constant on the sensor. The quadrat method, which compares the observed frequencies of the number of electron counts in the subsets of the study region with the predicted frequencies from a Poisson distribution, indicates a clustering-type departure from complete spatial randomness. To explore some of the basic principles governing the location of coherent electrons being counted, Ripley's K-function and the corresponding L-function of a stationary spatial point process were used to test the complete spatial randomness from the data. The maximum peak in the average of the L-functions was sensitive only to the mean counts per frame. Thus, clustering of spatial point patterns may result from abnormalities in the direct detection camera. When the interaction of the beam electrons with the sensor is included in the simulation, there is a reasonable match between the average of the L-functions and the experimental curves with the theoretically simulated curves.

关键词： electron counting direct detection sensor spatial point pattern spatial randomness

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A method for evaluating the degree of spatial and temporal avoidance in spatial point patterns

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JOURNAL OF GEOGRAPHICAL SYSTEMS 2022年第2期24卷 241-260页

作者： Sadahiro, Yukio Univ Tokyo Interfac Initiat Informat Studies Bunkyo Ku 7-3-1 Hongo Tokyo 1138656 Japan

This paper develops a new method for evaluating the degree of spatial and temporal avoidance in spatial point patterns. We consider point patterns that change over time, where points represent spatial objects that appear at certain locations, stay there for certain periods, and may finally disappear, such as buildings in cities, plants in fields, and birds' nests in forests. spatial avoidance in this paper refers to the phenomenon that points appear in sparse spaces while points disappear in dense spaces. spatial avoidance often leads to dispersed point patterns, which are observed in the distributions of drug stores, gas stations, and animal burrows. Temporal avoidance refers to the phenomenon that close points avoid the overlap of their lifetime. Temporal avoidance is found in the relationships between preys and predators, animal species that share the same water resources, and restaurants in shopping malls. The paper develops four measures to evaluate the spatial and temporal patterns of avoidance. Two measures consider the avoidance from a spatial perspective, while the other two focus on the temporal aspect of avoidance. To test the validity of the proposed method, this paper applies it to the analysis of the convenience stores in Shibuya-ku, Tokyo. The results indicated the proposed method's effectiveness and revealed the spatial and temporal patterns of avoidance of convenience stores that existing methods cannot detect.

关键词： spatial point pattern spatial avoidance Temporal avoidance Statistical analysis

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spatial point pattern analyses of Bovine viral diarrhea virus infection in domestic livestock herds and concomitant seroprevalence in wild white-tailed deer (Odocoileus virginianus) in New York State, USA

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JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION 2013年第2期25卷 226-233页

作者： Kirchgessner, Megan S. Dubovi, Edward J. Whipps, Christopher M. SUNY Coll Environm Sci & Forestry Syracuse NY 13210 USA Cornell Coll Vet Med New York State Anim Hlth Diagnost Ctr Ithaca NY USA

Bovine viral diarrhea virus (BVDV) is an economically important disease of domestic cattle that is capable of infecting cervids. A first step in the formulation of a regional BVDV management plan is a local assessment of the likelihood of pathogen transmission from wildlife to domestic livestock. To achieve this, blood samples were collected from hunter-harvested white-tailed deer (Odocoileus virginianus) throughout New York State in the fall of 2009 and 2010. The SVANOVIR BVDV p80-AB enzyme-linked immunosorbent assay (ELISA;Svanova Biotech AV, Uppsala, Sweden) was used to screen sera for anti-BVDV antibodies. Because this ELISA is not validated for use in white-tailed deer, sera that tested positive were tested again using serum neutralization to verify the presence of antibodies. spatial data describing the geographic location of BVDV antigen-positive cattle and camelid herds and BVDV-seropositive white-tailed deer were analyzed via the dual kernel density estimation method. In white-tailed deer, 7.48% (80/1,069) were BVDV-seropositive, whereas 3.43% (144/4,195) of tested herds were positive for BVDV antigen. An exploratory cluster analysis revealed 1 significant cluster of BVDV antigen-positive herds and 2 significant clusters of BVDV-seropositive deer. There was no spatial overlap between the clusters. The spatial point pattern and exploratory cluster analyses suggest that BVDV is maintained independently in domestic livestock herds in the western part of the state and in the white-tailed deer population in the northwestern part of the state.

关键词： Bovine viral diarrhea virus dual kernel density estimation method New York Odocoileus virginianus spatial point pattern white-tailed deer

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Toward a better understanding of forest spatial patterns:A generalisation of the uniform angle index

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ECOLOGICAL MODELLING 2025年 503卷

作者： Bu, Yuankun Li, Weizhong von Gadow, Klaus Wei, Jiangtao Zhao, Pengxiang Yang, Yanzheng Zhou, Chaofan Wang, Boheng Zhao, Xuan Northwest A&F Univ Coll Forestry Yangling 712100 Peoples R China Univ Gottingen Fac Forestry & Forest Ecol D-37077 Gottingen Germany Georg August Univ Gottingen D-37077 Gottingen Germany Natl Forestry & Grassland Adm Northwest Surveying & Planning Inst Xian Peoples R China Chinese Acad Sci Res Ctr Ecoenvironm Sci State Key Lab Urban & Reg Ecol Beijing 100085 Peoples R China Chinese Acad Forestry Natl Forestry & Grassland Adm Ecol & Nat Conservat Inst Key Lab Forest Ecol & Environm Beijing 100085 Peoples R China Chinese Acad Forestry Ecol & Nat Conservat Inst Beijing 100085 Peoples R China Natl Forest & Grassland Adm East China Survey & Planning Inst Hangzhou 310019 Peoples R China Minist Nat Resources Inst Geog Informat Cartog 1 Xian 710054 Peoples R China

spatial structure is important for characterizing a forest ecosystem. Among a myriad of spatial structure indices, the Uniform Angle Index (UAI) is rather special. The UAI quantifies a spatial pattern based on angles between neighbouring trees, thereby offering new insights into close range tree arrangements, competition, and stand dynamics. However, previous theoretical studies of the UAI have primarily relied on simulation stand and hence the uncertainty associated with them since its inception. Therefore, a mathematical derivation is still lacking. In this study, we present a theoretical framework for the UAI with the aim of broadening its applicability in quantifying the intensity of interactions among trees. Our theory is developed at two levels, the individual tree level and the stand level. The objective is to eliminate any simulation-induced uncertainty and bias and to enrich the theoretical foundation and applicability. We present a significant improvement of the UAI for estimating interaction strength among trees by the distance between an ideal and a real stand. This research highlights the opportunities for point pattern research in a new multidisciplinary science of forest ecology by growing knowledge and information along scientifically meaningful lines.

关键词： Complete spatial randomness Forest spatial pattern Hellinger distance between ideal stand (HDIS) spatial point pattern Uniform angle index

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Species-specific spatial associations shape tree recruitment dynamics in an arid mixed forest of Picea crassifolia and Pinus tabuliformis

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NEW FORESTS 2025年第1期56卷 1-16页

作者： Yang, Junlong Yu, Jian Wang, Guangping Li, Xiaowei Ningxia Univ Coll Forestry & Prataculture 489 Helanshan West Rd Yinchuan 750021 Ningxia Peoples R China State Key Lab Efficient Prod Forest Resources Yinchuan 750021 Peoples R China Jiangsu Vocat Coll Agr & Forestry Sch Landscape Architecture Jurong 212400 Peoples R China Ningxia Univ State Key Lab Breeding Base Land Degradat & Ecol R Yinchuan 750021 Peoples R China

Knowing the influence of intra- and interspecific associations on tree recruitment is essential to understanding forest dynamics. Here, we used spatial point-pattern analysis to investigate the distribution and association of two dominant species, Qinghai spruce (Picea crassifolia) and Chinese pine (Pinus tabuliformis), in an arid mixed coniferous forest in the Luoshan Mountains, Ningxia, China. The results showed that adults of either species were distributed randomly across all scales in the mixed forest. Regarding their intraspecific associations, the density of adult P. tabuliformis trees was positively associated with that of seedlings and saplings, while P. crassifolia adults lacked a close relationship to seedlings and saplings. However, in terms of intraspecific mortality, denser adult P. tabuliformis trees increased the mortality of seedlings and saplings on a small scale (< 5 m), while denser P. crassifolia adults consistently increased the mortality of seedlings and saplings at most spatial scales. Regarding their interspecific associations, the density of adult P. crassifolia trees was negatively correlated with that of P. tabuliformis saplings and seedlings, at both small and medium spatial scales (1-25 m and 1-17 m, respectively). Yet P. tabuliformis adults lacked a close relationship with P. crassifolia seedlings and saplings. Interestingly, regarding interspecific mortality, adult P. tabuliformis trees lessened the mortality of P. crassifolia seedlings, while P. crassifolia adults increased that of P. tabuliformis seedlings and saplings at most spatial scales. Collectively, these findings indicate that not only interspecific, but also intraspecific interactions, could drive forest dynamics in mixed stands in arid regions.

关键词： Arid mountains forest spatial point pattern Mixed coniferous forest Intraspecific association Interspecific association

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A Big Data Approach for the Regional-Scale spatial pattern Analysis of Amazonian Palm Locations

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REMOTE SENSING 2025年第5期17卷 784-784页

作者： Drouillard, Matthew J. Cummings, Anthony R. Univ Texas Dallas Sch Econ Polit & Policy Sci Geospatial Informat Sci Richardson TX 75080 USA Wesleyan Univ Dept Earth & Environm Sci Middletown CT 06459 USA

Arecaceae (palms) are an important resource for indigenous communities as well as fauna populations across Amazonia. Understanding the spatial patterns and the environmental factors that determine the habitats of palms is of considerable interest to rainforest ecologists. Here, we utilize remotely sensed imagery in conjunction with topography and soil attribute data and employ a generalized cluster identification algorithm, Hierarchical Density-Based spatial Clustering of Applications with Noise (HDBSCAN), to study the underlying patterns of palms in two areas of Guyana, South America. The results of the HDBSCAN assessment were cross-validated with several point pattern analysis methods commonly used by ecologists (the quadrat test for complete spatial randomness, Morista Index, Ripley's L-function, and the pair correlation function). A spatial logistic regression model was generated to understand the multivariate environmental influences driving the placement of cluster and outlier palms. Our results showed that palms are strongly clustered in the areas of interest and that the HDBSCAN's clustering output correlates well with traditional analytical methods. The environmental factors influencing palm clusters or outliers, as determined by logistic regression, exhibit qualitative similarities to those identified in conventional ground-based palm surveys. These findings are promising for prospective research aiming to integrate remote flora identification techniques with traditional data collection studies.

关键词： palms spatial point pattern HDBSCAN Guyana

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Information Divergences and Likelihood Ratios of Poisson Processes and point patterns

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IEEE TRANSACTIONS ON INFORMATION THEORY 2024年第12期70卷 9084-9101页

作者： Leskela, Lasse Aalto Univ Dept Math & Syst Anal Espoo 02150 Finland

This article develops an analytical framework for studying information divergences and likelihood ratios associated with Poisson processes and point patterns on general measurable spaces. The main results include explicit analytical formulas for Kullback-Leibler divergences, Renyi divergences, Hellinger distances, and likelihood ratios of the laws of Poisson point patterns in terms of their intensity measures. The general results yield similar formulas for inhomogeneous Poisson processes, compound Poisson processes, as well as spatial and marked Poisson point patterns. Additional results include simple characterisations of absolute continuity, mutual singularity, and the existence of common dominating measures. The analytical toolbox is based on Tsallis divergences of sigma-finite measures on abstract measurable spaces. The treatment is purely information-theoretic and free of topological assumptions.

关键词： Poisson random measure inhomogeneous Poisson process point process spatial point pattern Renyi divergence Tsallis divergence Hellinger distance mutual information Chernoff information Bhattacharyya distance

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Functional summary statistics and testing for independence in multi-type point processes on the surface of three dimensional convex shapes

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spatial STATISTICS 2025年 67卷

作者： Ward, S. Cohen, E. A. K. Adams, N. M. Imperial Coll London Dept Math South Kensington Campus London SW7 2AZ England

The fundamental functional summary statistics used for studying spatial point patterns are developed for marked homogeneous and inhomogeneous point processes on the surface of a sphere. These are extended to point processes on the surface of three dimensional convex shapes given the bijective mapping from the shape to the sphere is known. These functional summary statistics are used to test for independence between the marginals of multi-type spatial point processes with methods for sampling the null distribution developed and discussed. This is illustrated on both simulated data and the RNGC galaxy point pattern, revealing attractive dependencies between different galaxy types.

关键词： spatial point pattern Convex shape Functional summary statistics Marked point process

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