Spatial Hierarchical Structure Research Articles

A backfitting maximum likelihood estimator for hierarchical and geographically weighted regression modelling, with a case study of house prices in Beijing

Geographically weighted regression (GWR) and its extensions are important local modelling techniques for exploring spatial heterogeneity in regression relationships. However, when dealing with spatial data of overlapping samples – for example, when precise locational information is aggregated to a shared neighbourhood to avoid revealing the addresses of individual survey respondents – GWR-based models can encounter several problems, including obtaining reliable bandwidths. Because data with this characteristic exhibit spatial hierarchical structures, we propose combining hierarchical linear modelling (HLM) with GWR to give a hierarchical and geographically weighted regression (HGWR) model that divides coefficients into sample-level fixed effects, group-level fixed effects, sample-level random effects, and group-level spatially weighted effects. This paper presents a back-fitting likelihood estimator to fit the model, a simulation experiment that suggests that HGWR is better able to capture these effects and the spatial heterogeneity within them than are traditional HLM or GWR models, and a case study looking at predictors of housing price in Beijing, China. The ability of HGWR to tackle both spatial and group-level heterogeneity simultaneously suggests its potential as a promising data modelling tool for handling spatio-temporal big data with spatially hierarchical structures.

Mapping socio-economic status using mixed data: a hierarchical Bayesian approach

Abstract We propose a Bayesian hierarchical model to estimate a socio-economic status (SES) index based on mixed dichotomous and continuous variables. In particular, we extend Quinn’s ([2004]. Bayesian factor analysis for mixed ordinal and continuous responses. Political Analysis, 12(4), 338–353. https://doi.org/10.1093/pan/mph022) and Schliep and Hoeting’s ([2013]. Multilevel latent Gaussian process model for mixed discrete and continuous multivariate response data. Journal of Agricultural, Biological, and Environmental Statistics, 18(4), 492–513. https://doi.org/10.1007/s13253-013-0136-z) factor analysis models for mixed dichotomous and continuous variables by allowing a spatial hierarchical structure of key parameters of the model. Unlike most SES assessment models proposed in the literature, the hierarchical nature of this model enables the use of census observations at the household level without needing to aggregate any information a priori. Therefore, it better accommodates the variability of the SES between census tracts and the number of households per area. The proposed model is used in the estimation of a socio-economic index using 10% of the 2010 Ghana census in the Greater Accra Metropolitan area. Out of the 20 observed variables, the number of people per room, access to water piping and flushable toilets differentiated high and low SES areas the best.

Nature-inspired architecture combining organic–inorganic frameworks: Unique structure and active sites toward a stable anti-corrosion coating

As a promising technology for material engineering, hybrid organic-inorganic (HOI) materials with a diversity of spatial hierarchical structures have become prospective candidates for cutting-edge applications. In this hot field of hybrid materials, considerable progress has been made in the manufacture of new systems toward large applicability. However, the complex synthesis pathways, stability and durability of such frameworks remain ongoing challenges facing us that seriously hinder the practical viability of this technology. Herein, an effective nest-like network is skillfully designed with both unique architectural design and outstanding structural activity of the self-assembled material resulting from a suitable band-gap configuration. Moreover, the present work put forward how the nest-like network would architecturally upgraded on the pre-existing Al2O3 porous film by plasma electrolytic oxidation (PEO) with the synergy of two organic molecules resulting in a tunable organic-inorganic hybrid material. This study inspired by the natural nest is realized to offer more adsorption and reaction sites in order to meet an excellent anti-corrosion performance, meanwhile achieving outstanding long-term stability. This strategy would open up a whole new possibility of the synergistic effect of two or more molecules for the fabrication of new hybrid materials not only endowed with excellent properties but also with facile synthetic route.

Compact representations of spatial hierarchical structures with support for topological queries

Among different spatial data models, the topological model for spatial regions explicitly represents common boundaries. This model pursues the efficiency of topology-related queries and the elimination of data redundancy. This paper proposes several space-efficient data structures to support access to the topological representation of two-dimensional regions that are organized in a multi-granular or hierarchical structure, such as the political and administrative partition of a country. In the context of these hierarchies, we focus on queries that search for inclusion, disjointness, and adjacency between regions. The proposed structures build upon compact planar graph embeddings, which show to have a good trade-off between space and time.

Untangling the association between urban mobility and urban elements

ABSTRACT Understanding complex urban systems necessitates untangling the relationships between diverse urban elements such as population, infrastructure, and socioeconomic activities. Scaling laws are basic but effective rules for evaluating a city’s internal growth logic and assessing its efficiency by investigating whether urban indicators scale with population. To date, only limited research has empirically explored the scaling relations between variables of urban mobility in mega-cities at an intra-urban scale of a few meters. Using multiple urban-sensed and human-sensed data, this study proposes a thorough framework for quantifying the scaling laws in a city. To begin, urban mobility networks are built by aggregating population flows using large-scale mobile phone tracking data. To demonstrate the spatiotemporal variability of urban mobility, various network-based mobility measures are proposed. Following that, three different features of urban mobility laws are exposed, explaining spatial agglomeration, spatial hierarchical structures, and the temporal growth process. The scaling correlations between urban indicators pertaining to socioeconomic features and infrastructure and a mobility-population measure are then quantified using multi-sourced urban-sensed data. Applying this framework to the case study of Shenzhen, China revealed (a) spatial travel heterogeneity, hierarchical spatial structures, and mobility growth, and (b) not only a robust sub-linear relationship between infrastructure volume and population, but also a sub-linear relationship for socioeconomic activity. The identified scaling laws, both in terms of mobility measures and urban indicators, provide a multi-faceted portrait of the spatio-temporal variations of urban settings, allowing us to better understand intra-urban developments and, consequently, provide critical policy evaluations and suggestions for improving intra-urban efficiency in the future.

Multiscale and hierarchical reaction mechanism in a lithium-ion battery

The key to improving the performance of lithium-ion batteries is to precisely elucidate the temporal and spatial hierarchical structure of the battery. Lithium-ion batteries consist of cathodes and anodes and a separator containing an electrolyte. The cathodes and anodes of lithium-ion batteries are made of a composite material consisting of an active material, a conductive material, and a binder to form a complex three-dimensional structure. The reaction proceeds as lithium ions are repeatedly inserted into and removed from the active material. Therefore, the lattice of the active material is restructured due to ion diffusion, which results in phase change. At the active material–electrolyte interface, the insertion and de-insertion of lithium ions proceed with the charge transfer reaction. The charge–discharge reaction of a lithium-ion battery is a nonequilibrium state due to the interplay of multiple phenomena. Analysis after disassembling a battery, which is performed in conventional battery research, does not provide an accurate understanding of the dominant factors of the reaction rate and the degradation mechanism, in some cases. This review introduces the results of research on the temporal and spatial hierarchical structure of lithium-ion batteries, focusing on operando measurements taken during charge–discharge reactions. Chapter 1 provides an overview of the hierarchical reaction mechanism of lithium-ion batteries. Chapter 2 introduces the operando measurement technique, which is useful for analysis. Chapter 3 describes the reaction at the electrode–electrolyte interface, which is the reaction field, and Chapter 4 discusses the nonequilibrium structural change caused by the two-phase reaction in the active material. Chapter 5 introduces the study of the unique reaction heterogeneity of a composite electrode, which enables practical energy storage. Understanding the hierarchical reaction mechanism will provide useful information for the design of lithium-ion batteries and next-generation batteries.

Regional inequalities in benzene exposures across the European petrochemical industry: A Bayesian multilevel modelling approach

BackgroundPollutants released from the petrochemical industry are thought to increase the risk of mortality in fence-line communities, yet the results from previous studies are often inconsistent and lack a global perspective, hampered by the absence of cohesive cross-country research. ObjectivesTo provide the first Pan-European analysis of benzene exposures from the petrochemical industry, connecting polluting practices to pollution episodes and disparities in regional mortality rates, identifying the measures of best environmental practice to mitigate adverse outcomes. MethodsThe activity, classification and location of onshore petrochemical facilities within EU-28 Member States were extracted from the ‘European Pollutant Release and Transfer Register’ (E-PRTR), which holds records on 31,753 industrial operations for the reporting period of 2007–15. Parent company records were collected from the Moody's Analytics Amadeus database of 487,338 active companies across Europe. The EUROSTAT census provided records of income, life expectancy, and the underlying demographics used to calculate standardised health outcomes based on 9,936 sub-populations within the NUTS2 regions. The European Environment Agency provided ambient concentrations of benzene from 579 air quality stations. Bayesian multilevel models were constructed to account for variability caused by spatial hierarchical structures, uncertainty in the estimates, and to incorporate both individual and group-level influences. ResultsHigher levels of benzene emissions from petrochemical operations, both overall and in terms of specific pollution events, were associated with increased mortality rates for nearby residential populations, particularly in areas with socioeconomic deprivation. We identify uneven patterns of polluting practices within the industry, and locations that require epidemiological studies. ConclusionsWhile petrochemical facilities in all European Union regions are regulated to be compliant with the annual average benzene limit of 5 μg/m3, uneven exposures still present regional health inequalities. We recommend extending benzene regulations to an hourly or daily limit, alongside the strengthening of regulation for other toxic petrochemical releases.

Diversity from genes to ecosystems: A unifying framework to study variation across biological metrics and scales.

Biological diversity is a key concept in the life sciences and plays a fundamental role in many ecological and evolutionary processes. Although biodiversity is inherently a hierarchical concept covering different levels of organization (genes, population, species, ecological communities and ecosystems), a diversity index that behaves consistently across these different levels has so far been lacking, hindering the development of truly integrative biodiversity studies. To fill this important knowledge gap, we present a unifying framework for the measurement of biodiversity across hierarchical levels of organization. Our weighted, information‐based decomposition framework is based on a Hill number of order q = 1, which weights all elements in proportion to their frequency and leads to diversity measures based on Shannon's entropy. We investigated the numerical behaviour of our approach with simulations and showed that it can accurately describe complex spatial hierarchical structures. To demonstrate the intuitive and straightforward interpretation of our diversity measures in terms of effective number of components (alleles, species, etc.), we applied the framework to a real data set on coral reef biodiversity. We expect our framework will have multiple applications covering the fields of conservation biology, community genetics and eco‐evolutionary dynamics.

САКРАЛЬНИЙ ЛАНДШАФТ: ЗМІСТ І ФУНКЦІЇ

The relevance of the research of scientific approaches to the content of the notion of sacred landscape, its structure and functions are substantiated. The article considers the sacral landscape as a holistic, stable system characterized by spatial and temporal organization, which ensures the process of uniting the nation, preserves authentic culture, opposes the destruction of spiritual foundations, has a great social, economic and political significance. We established the interdisciplinary nature of the investigation, which covers a wide range of issues related to various scientific disciplines: geography, social theory, culture, philosophical anthropology. The analysis of scientific publications concerning the interpretation of the concept of sacred and its etymology has been studied. The difference between the concepts of sacred and religious is substantiated. The content of the concept of sacredness, which gives people, actions, territory and other objects of such quality that separates them from the ordinary things and places them in the position of exceptional value and significance and on this basis requires an exceptional attitude, is determined. The modern approaches to the interpretation of the notion of the sacral landscape are investigated. It has been established that a large proportion of the sacred space belongs to religious objects. The main instruments of the “sacralization” of the landscape are identified – symbolization, myth and event that gives it an extremely valuable (holy) meaning. The experience of using the integrated approach in the interpretation of the notion of sacral landscape is substantiated. The definition of where the sacred landscape is considered as a natural, natural-anthropogenic, anthropogenic system, which is associated with certain life symbols, myths, significant events, religious feelings, is extremely valuable for a person or group of people and needs a special respect and protection. The results of the investigation indicate that the sacred landscape can be considered as a system that has a spatial-hierarchical structure, where we can distinguish individual, local, regional, national and global levels. The examples of sacred landscapes of different levels are given. The analysis of scientific publications about the functions of sacred geographical objects is carried out. It was established that such researches were based on the influence of sacred geographical objects on visitors, which testifies the integrity of interconnections in the complex system “man-landscape”. The leading approaches to classification of landscape functions are investigated. The classification of functions of the sacred landscape is developed, classes and subclasses of such functions are singled out. The political, social, economic and ecological functions of the sacred landscape, that have an environment formative role are characterized. The functions presented in the article have a theoretical value, since in practice there are close interrelationships between them, that is, they integrate and complement each other.

A Green and Sustainable Route to Carbohydrate Vinyl Ethers for Accessing Bioinspired Materials with a Unique Microspherical Morphology.

Synthesizing chemicals and materials from renewable sources is one of the main aims of modern science. Carbohydrates represent excellent renewable natural raw materials that are ecofriendly, inexpensive, and biologically compatible. A green procedure has been developed for the vinylation of carbohydrates by using readily available calcium carbide. Various carbohydrates were utilized as starting materials, resulting in mono-, di-, and tetravinyl ethers in high to excellent yields (81-92 %). The synthesized biobased vinyl ethers were utilized as monomers in free radical and cationic polymerizations. A unique combination of a smooth surface and intrinsic microcompartments was achieved in the synthesized materials. Two types of biobased materials were prepared involving microspheres and intrinsic hollow compartments in polymers. Scanning electron microscopy with built-in ion beam cutting was applied to reveal the spatial hierarchical structures in 3D space.

Spatial pattern and fractal characteristics of producer services' external function in China

Using the Zipf's law and differentiated index, we analyze the spatial pattern, size hierarchy and fractal evolution of producer services' external function at provincial and city scales of China from 2003 to 2011, which are based on urban basic economic theory.Conclusions can be drawn as follows: The external functions of China's producer services have significantly differences, which show a trend of polarization at different scales, and widen the gaps among the external functions of different provinces and cities. At provincial scale, nine provincial units which are Xinjiang, Shandong, Henan, Hubei, Chongqing, Guizhou, Yunnan,Jiangxi and Fujian, do not have external function; at city scale, they generate a number of intensive areas of external function, which are mainly in the northeastern China and eastern coastal China and present different spatial structures and obvious changes in the characteristics,that is to say, the spatial hierarchical structure in the eastern China is better than that in the central and western China. The rank- size distributions of the producer services' external function at provincial and city scales comply with Zipf's law, however, they are characterized by single fractal at provincial scale and dual fractals at city scale; the grade equilibrium of the external service flow in the first scale area is slightly better than that at the provincial scale.The second and ineffective scale areas are central centers of local service, showing a significant change in the internal structure of the system and widening the gap among the urban external functions. External function cities can be divided into five types of service centers. High-grade service centers' external function are improving faster than that of other types, and the gaps are widening among different size hierarchy service centers.

Zones and segments as taxa used in the hierarchical classification of riverine landscapes: a case study of the smrečianka brook, Slovak Republic

Abstract A river is a highly complex structure and the constituent of landscape and catchment basin from which it drains water. In the holistic concept, a river is defined in mutual interactions with its surroundings as a spatial system - the riverine landscape. As a product of fluvial processes, the riverine landscape has a regular spatial hierarchical structure, which is determined by the structure of its morphology, substrate, biota, land cover and socioeconomic structures. The aim of this paper is to verify the river landscape hierarchical classification and to identify the so-called higher taxa - zones and segments in the Smrečianka valley. The main data sources were hydrological maps at 1:50 000, topographic maps at 1:10 000 and 1:25 000, GIS database levels, geological maps at 1:50 000, and the boundaries were specified by a field survey

Network analysis of China’s aviation system, statistical and spatial structure

Aviation systems are less geographically constrained compared to ground transportation because their routes are not so affected by geographical conditions. For this reason, aviation systems are endowed to some extent with a distinctive network topology and spatial pattern. In this article, the statistical features of China’s aviation system (CAS) are investigated through a complex network approach by examining weekly flight patterns. The correlation study proves the existence of a spatial hierarchical structure within China’s aviation network, which implies a more complex spatial mechanism. Subsequently the spatial structure of CAS is explored based on the flight distances between airport cities. In light of three measurements of node strength, population and GDP, It has been decided that the spatial effect of China’s aviation system should be analyzed separately in term of different distance scales. Only for medium- and long-distance travel, the flight patterns conform to a gravitation law; therefore, the distance dependence function can be generalized as a scaling relationship. In summary, from a complex network angle, this paper provides preliminary but enlightening insights to understanding the unique spatial mechanism of aviation systems.

A progressive line simplification algorithm

An application of line simplification considering spatial knowledge is described. A method for identifying potential conflict regions, in order to avoid the self-intersection of generalized, lines, is also discussed. Further-more, a new progressive line simplification algorithm is presented. From the view point of spatial cognition, a spatial hierarchical structure is proposed, and its application to construction of spatial knowledge related to a line is explained.

都市施設の空間階層構造を記述するための一手法

本稿は,施設の空間階層構造を記述し,その形成要因を推定するための手法を提案するものである.既存の方法は,施設は階層構造をもっているという仮定に基づいているため,ランダムに分布している施設についても階層構造を見出してしまう危険性があり,ここではとくにこの問題点を克服することに主眼をおいている. 階層構造は,施設の順位と位置によって定め,ツリーグラフとして記述する.さらに,その特性をみるためにグラフ理論的な指標をいくつか導入する.これらの指標を,位置と規模とがランダムな施設分布について計算し,実際の施設階層構造の場合をそれと比較することによって,階層構造を形成する要因を推定することができる. 実証分析としては,西宮市の商業施設を例として取り上げた.その結果,西宮市の商業施設の階層構造は,クリスタラーのモデルよりも,ランダムな階層構造に近いことがわかった.