Complex Spatial Systems Research Articles

Semi-analytical dynamic modeling and fluid-structure interaction analysis of L-shaped pipeline

The traditional semi-analytic modeling is mainly aimed at the straight pipeline with simple boundary conditions. In contrast, the actual aero-engine pipeline needs to consider the effects of complex configuration, boundary and multiple clamps, so proposing an improved semi-analytic method to model an arbitrary fluid-conveying L-shaped pipeline is challenging. Based on the Hamiltonian principle, the differential equations of the L-shaped pipeline are derived. Then, the modal shape functions are determined under the conditions that the elastic support points and the joints of the straight pipeline and the curved pipeline meet the deformation coordination requirements. The proposed semi-analytical model is verified by comparing the natural frequencies and mode shapes obtained from the finite element method using ANSYS and experiment; the error of each order natural frequency is less than 5 %. In addition, the model is verified under various working conditions: different center angle and boundary conditions (clamp position and pipeline end constraints). The effects of the fluid velocity and pressure on the natural characteristics of the L-shaped pipeline are also analyzed. The results show that under the critical pressure of 60.51 MPa and the critical velocity of 247 m/s, the natural frequency decreases with the increase of fluid velocity and pressure. The proposed method can provide theoretical support for efficient and accurate modeling of complex spatial pipeline systems.

Tipping points in spatial ecosystems driven by short-range correlated noise.

Complex spatial systems can experience critical transitions or tippings on crossing a threshold value in their response to stochastic perturbations. While previous studies have well characterized the impact of white noise on tipping, the effect of correlated noise in spatial ecosystems remains largely unexplored. Here, we investigate the effect of both multiplicative and additive Ornstein-Uhlenbeck (OU) correlated noise on the occurrence of critical transitions in spatial ecosystems. We find that decreasing the noise correlation time of OU (exponentially correlated) noise aggravates the chance of critical transitions in spatiotemporal ecological systems. Our results hold good and are supported by the analysis of three well-studied spatial ecological models of varying nonlinearity. We also compute spatial early warning indicators (e.g., spatial variance, spatial skewness, and spatial correlation) to determine their reliability in anticipating tipping points with variations in noise correlation. The indicators of critical transitions exhibit mixed success in forewarning the occurrence of a tipping point, as indicated by the distribution of Kendall's rank correlation.

General Spatial Pattern and Meta-Pattern Model for Problems That Need Analytical Approach in Complex Spatial Systems

Spatial Pattern (SP) Description, Identification, and Application Methodology (SPDIAM) was developed for describing and detecting spatial economic, social, and environmental phenomena and providing basic information technology (IT) artefacts that can be used for the spatial analysis development using GIS technologies. SPDIAM allows urban planning and design practitioners to describe SP in a computerized manner, identify SP automatically, and apply them in the spatial planning and design domain. In this article, we explain the general SP and spatial meta-pattern model, used in SPDIAM, that is based on the theory of Complex Spatial System (CSS), spatial configuration, and spatial capital concepts and is presented using UML diagrams as standard used for visualization of project models from structure and behavior points of views. The practical experiment of describing and identifying 6 basic spatial meta-pattern values is conducted using the new algorithm that combines Space Syntax method, Visibility Graph Analysis (VGA), and VGA measures to create a computer model of space and to quantify its configuration, which can then be used to handle geographic and geometric data associated with attribute information, to perform spatial, mathematical, and statistical calculations and to visualize SP. The results of the experiment show that the model and the algorithm are appropriate for spatial meta-patterns identification, and the best results can be achieved using VGA measure Isovist Compactness. In the future, general SP and the spatial meta-pattern model can be used to describe and identify complex SP and to solve problems in CSS with the help of the spatial meta-pattern values described in this article.

Method proposal for the management of geographic information in water and sewer companies

Geographic information has been used in water and sewage companies and currently has worldwide application, in rich and poor countries, from basic actions such as georeferencing points of interest to cross-referencing complex Enterprise Resource Planning (ERP) and Spatial Data Infrastructures systems together with other public services. But has the creation, use and management of this information been carried out successfully harnessed? Considering the constant changes occurred in Information Technology, in the demography of urban areas, in water and sewage systems and in corporate management, we propose a method for implementing Geographic Information Systems (GIS) for water and sewage services in metropolitan areas. Based on two models, it is possible to elaborate requirements related to the use and management of GIS and guide actions and decisions for their development, considering the organizational management of companies and the regional context in which they operate.

FORMATTING OF JULIA SETS OF COMPLEX DYNAMIC SYSTEMS

It is of crucial significance to study a class of complex dynamic planar and spatial systems with disparate coefficients by taking advantage of thoughts of Julia set. In this paper, we present theoretical control methods for the stable domain and Julia sets of systems. Then, we utilize symmetry to exhibit the forms of compositional Julia sets of complex dynamic planar systems. Furthermore, by selecting different coefficients, the location, size, area and shape of Julia set can be controlled, the spatial Julia sets also have certain characteristics, this supplies a possible reference for how to control the stable domain of specific complex dynamic systems. The simulation results are in good agreement with the effectiveness of the methods.

Synchrony and Perturbation Transmission in Trophic Metacommunities

AbstractIn a world where natural habitats are ever more fragmented, the dynamics of metacommunities are essential to properly understand species responses to perturbations. If species' populations fluctuate asynchronously, the risk of their simultaneous extinction is low, thus reducing the species' regional extinction risk. However, identifying synchronizing or desynchronizing mechanisms in systems containing several species and when perturbations affect multiple species is challenging. We propose a metacommunity model consisting of two food chains connected by dispersal to study the transmission of small perturbations affecting populations in the vicinity of an equilibrium. In spite of the complex responses produced by such a system, two elements enable us to understand the key processes that rule the synchrony between populations: (1) knowing which species have the strongest response to perturbations and (2) the relative importance of dispersal processes compared with local dynamics for each species. We show that perturbing a species in one patch can lead to asynchrony between patches if the perturbed species is not the most affected by dispersal. The synchrony patterns of rare species are the most sensitive to the relative strength of dispersal to demographic processes, thus making biomass distribution critical to understanding the response of trophic metacommunities to perturbations. We further partition the effect of each perturbation on species synchrony when perturbations affect multiple trophic levels. Our approach allows disentangling and predicting the responses of simple trophic metacommunities to perturbations, thus providing a theoretical foundation for future studies considering more complex spatial ecological systems.

The Transformation of Social and Cultural Space in the Context of the Development of Transport Corridors

This article discusses the methodology of analysis and forecasting of complex spatial systems, taking into account a lot of economic, social and cultural relationships that determine the specifics of the individual territories’ development. Particular attention is paid to the formation of specific zones on the basis of urban settlements along the path of transport corridors. In this regard, the authors introduce the concept of ”urban renewal centers” and give a definition. For its disclosure, the methodological part provides a list of related concepts, defines their boundaries and relationships, and also reveals the essence of the definitions of ‘transport corridor’ and ‘zone of transport corridor’. The authors proposed the use of vector estimates for the analysis of heterogeneous spatial systems of extended information volumes with the inclusion of sociological data and problem-oriented adaptation of visualization and processing of graphic data. As a result of a new, more detailed statement of the problem, we can go on to assess the prospects for the development of space for the complex and heterogeneous macro-regional and transboundary transport corridor Ural — Northern Kazakhstan. The study has fixed that development of urban renewal centers acts as a driver for the development of social and cultural spheres, as well as general economic conditions. The social and cultural transformation of urban settlements over time begins to determine their economic development potential. Such settlements are becoming centers of gravity in the labor market with many far-reaching development scenarios.
 Keywords: regional development, urban settlements, urban renewal, transport corridor, visualization

Research on Architectural Function of Taoping Qiang Village Based on Functionalism

The study in ABA prefecture of Sichuan province Gutang peach Qiangzhai as an example, based on the functional of peach Qiangzhai building function of research and exploration, peach Qiangzhai location and complex spatial systems, under the background of new era, the modern society of peach Qiangzhai under the influence of double vision of peach Qiangzhai identity, conclusion and reflection on the influence of the old and new Qiangzhai phenomenon, Carry out comparative studies and put forward their own thinking hypotheses. It is inevitable that Taoping Qiang Village will change in the future. I want to preserve the excellent cultural essence of the Qiang nationality while not sticking to it. It must keep pace with The Times and protect and develop it in the process.

Анализ трансформации «зеленых зон» неоднородного социального пространства: на примере агломерации Челябинска и городского бора

The research is focused on the problems of transforming a complex heterogeneous spatial system, urban agglomeration with a unique natural complex. The paper touches upon the following issues: restrictions on spatial development, zoning of territories, transformation of the settlement framework, social transformations, and integration of the most significant city-forming objects. To predict transformations in such a system, a complex multilevel model is considered — “the biosphere core vs. urban environment”. Forming such a model to analyze the prospective development of the territory involves updating the methodology aimed at the systemic socio-ecological-economic analysis of developing heterogeneous spatial systems, integration of cartographic and digital information, adaptation of IT visualization technologies, including the “neogeography” toolkit. In the study the authors analyze the main prospects for the spatial territory development as exemplified by developing the urban environment of the Chelyabinsk agglomeration with a unique “green zone” (Chelyabinsk urban forest), complex multi-level socio-economic system. The main research results create the prerequisites for a significant expansion of the possibilities for analyzing the prospects for sustainable socio-ecological-economic development of complex spatial systems with unique natural objects and effective management of regional development.

Equivalent relation between normalized spatial entropy and fractal dimension

Fractal dimension is defined on the base of entropy, including macro state entropy and information entropy. The generalized correlation dimension of multifractals is based on Renyi entropy. However, the mathematical transform from entropy to fractal dimension is not clear in both theory and practice. This paper is devoted to revealing the new equivalence relation between spatial entropy and fractal dimension using the box-counting method. By means of a set of regular fractals, the numerical relationship between spatial entropy and fractal dimension is examined. The results show that the ratio of actual entropy (Mq) to the maximum entropy (Mmax) equals the ratio of actual dimension (Dq) to the maximum dimension (Dmax). The spatial entropy and fractal dimension of complex spatial systems can be converted into one another by using functional box-counting method. The theoretical inference is verified by observational data of urban form. A conclusion is that the normalized spatial entropy is equal to the normalized fractal dimension. Fractal dimensions proved to be the characteristic values of entropies. In empirical studies, if the linear size of spatial measurement is small enough, a normalized entropy value is infinitely approximate to the corresponding normalized fractal dimension value. Based on the theoretical result, new spatial indexes of urban space filling can be defined, and multifractal parameters can be generalized to describe both simple systems and complex systems.

Representing Complex Evolving Spatial Networks: Geographic Network Automata

Many real-world spatial systems can be conceptualized as networks. In these conceptualizations, nodes and links represent system components and their interactions, respectively. Traditional network analysis applies graph theory measures to static network datasets. However, recent interest lies in the representation and analysis of evolving networks. Existing network automata approaches simulate evolving network structures, but do not consider the representation of evolving networks embedded in geographic space nor integrating actual geospatial data. Therefore, the objective of this study is to integrate network automata with geographic information systems (GIS) to develop a novel modelling framework, Geographic Network Automata (GNA), for representing and analyzing complex dynamic spatial systems as evolving geospatial networks. The GNA framework is implemented and presented for two case studies including a spatial network representation of (1) Conway’s Game of Life model and (2) Schelling’s model of segregation. The simulated evolving spatial network structures are measured using graph theory. Obtained results demonstrate that the integration of concepts from geographic information science, complex systems, and network theory offers new means to represent and analyze complex spatial systems. The presented GNA modelling framework is both general and flexible, useful for modelling a variety of real geospatial phenomena and characterizing and exploring network structure, dynamics, and evolution of real spatial systems. The proposed GNA modelling framework fits within the larger framework of geographic automata systems (GAS) alongside cellular automata and agent-based modelling.

Hybrid Automata Library: A flexible platform for hybrid modeling with real-time visualization.

The Hybrid Automata Library (HAL) is a Java Library developed for use in mathematical oncology modeling. It is made of simple, efficient, generic components that can be used to model complex spatial systems. HAL’s components can broadly be classified into: on- and off-lattice agent containers, finite difference diffusion fields, a GUI building system, and additional tools and utilities for computation and data collection. These components are designed to operate independently and are standardized to make them easy to interface with one another. As a demonstration of how modeling can be simplified using our approach, we have included a complete example of a hybrid model (a spatial model with interacting agent-based and PDE components). HAL is a useful asset for researchers who wish to build performant 1D, 2D and 3D hybrid models in Java, while not starting entirely from scratch. It is available on GitHub at https://github.com/MathOnco/HAL under the MIT License. HAL requires the Java JDK version 1.8 or later to compile and run the source code.

Principles of structural construction of spatially adaptive electromechanical systems with variable structure and geometry of the active surface

The salient trends of the development of modern technology, which is associated with the creation of complex spatial systems with the ability to adapt the spatial geometry of the working unit in accordance with changes in external factors are analyzed. The principles of genetic structure formation of spatially distributed modular electromechanical systems with adaptive active surface geometry are determined. The macrogenetic programs of genetically permissible basic Species of electromechanical structures with variable geometry and orientation of the active surface are determined. The dominant role of replication, mutation, and structural isomerism operators in the synthesis of spatially adaptive systems of a modular type are shown. The mechanisms of intergeneric mutations were first investigated, which determine the principles of structure formation of the objects of "elastic electromechanics", the functioning of which is accompanied by a change of the geometry of the active surface. The presence of a stable deterministic relationship between the electromagnetic chromosomes of the genetic program and isomeric chromosome compositions, with the layout of the active inductor modules and the type of spatial movement of the technological product were identified. The reliability of genetic programs and synthesis results is confirmed by the example of project synthesis of a competitive modular electromechanical system with an adaptive spatial structure, consisting of a robotic technological complex designed to operate steel pipes and sheet metal. The research results provide a systematic basis for the formulation of problems of innovative synthesis of new structural varieties of electromechanical systems with spatially adaptive modular structure of the active surface.

A lightweight bionic design for a scanner based on the 3D architecture of root system of pine trees

Lightweight design is usually a critical criterion in many engineering fields. In addition to the well-developed method topology optimization, structural bionics is also considered an effective approach to obtain innovative designs with lightweight. In nature, trees have evolved highly developed root systems to maximize the efficiency in anchorage. Inspired by the 3D branch structure of plant roots, this paper selects the root system of pine trees as a biological prototype for the optimization of a scanner which has a strict requirement for the flatness. First, a topology-optimized structure of the scanner is modeled and simulated for its mechanical behavior. Next, architectural and mechanical characteristics of the tap root system of pine trees are investigated through sensitivity analysis. Similarity analysis between the root system and the scanner is performed from three aspects. Then, by imitating the spatial configuration of pine tree roots, a bionic design for the scanner is proposed and modeled. Finally, finite element method (FEM) is carried out to evaluate the mechanical performance of the original model, the bionic model, and the topology-optimized model in terms of weight, dynamics response, and specific stiffness efficiency. Comparison results show that the proposed bionic model provides the best lightweight solution for the scanner, followed by the topology-optimized model. The proposed bionic model suggests a new solution to the design of the supporting system of “tower-like” structures and extends the application of branch-based bionics from planar systems to complex spatial systems.

Induced Perturbation Network and tiling for modeling the L55P Transthyretin amyloid fiber

Abstract Protein structures are complex spatial systems, formed by the three-dimensional arrangement of amino acids, that interact through atomic contacts. It is fundamental to understand the perturbation mechanisms associated with the amino acid mutations that lead to changes in a protein dynamics, as such mutations can lead to diseases. We present a methodology based on Amino Acid Networks and the use of Induced Perturbation Networks to infer the impact of amino acid mutations on a protein’s dynamics and the use of a tiling formalism to model protein aggregation. We apply this methodology to the case study of the L55P Transthyretin (TTR) variant, one of the most pathogenic mutations of TTR, due to its increased tendency to aggregate into amyloid fibers. We show that another pathogenic variant, V30M TTR, produces different results, reflecting a different pathogenic mechanism compared to L55P TTR and that the results differ for pathogenic and non-pathogenic variants (L55P and V30M TTR pathogenic variants versus Tl 19Y and Tl 19M non-pathogenic variants).

Participatory development of digital support tools for local-scale energy transitions: Lessons from two European case studies

Spatial planning systems at local and regional levels are often not well-adapted to the growth of small-scale and local social innovations in renewable energy. Participatory decision support tools have been developed to support the implementation of many areas of environmental policy, but are less common in energy contexts. In response to this knowledge gap, we discuss, compare and contrast the participatory development of two different types of digital support tools for the cases of Spain and the Netherlands, leading to insights into the characteristics that local-level stakeholders find particularly desirable. We adopt an integrative approach, hybridizing implementation theory and action research for, respectively, analysis of implementation characteristics of key actors, and knowledge co-construction with participant stakeholders. The tools developed represent two extremes of the spatial decision support tool spectrum, a simple touchscreen application on the one hand (COLLAGE) and a more complicated spatial model on the other (APoLUS). COLLAGE was used and well-liked by stakeholders, whereas APoLUS was not adopted by the participant group, who nevertheless contributed much essential information to its development. We identify eight key differences between the two tools which shed light on the nature of bottom-up energy transition processes: 1: Target users; 2: Target scale of action; 3: Relevance to users’ needs; 4: Interactive quality; 5: Key emphasis; 6: Level of complexity; 7: Ease of communication of tool rationale; 8: Cost. The differences between these tools also relate to a recognized dichotomy in sustainability transition research, with complex spatial support systems like APoLUS tending towards descriptive-analytical modes of sustainability science and simpler tools like COLLAGE being more clearly related to transformational modes. Approaches to supporting local-scale energy transitions that are able to span both modes are likely to become increasingly relevant as the climate crisis evolves. We also identify a research gap between support tools for implementation of established policy and support tools for transformative actions at local scales, and suggest the study of digital “transition support tools” as a promising avenue for future research.

Spatial Measures of Urban Systems: from Entropy to Fractal Dimension.

One type of fractal dimension definition is based on the generalized entropy function. Both entropy and fractal dimensions can be employed to characterize complex spatial systems such as cities and regions. Despite the inherent connection between entropy and fractal dimensions, they have different application scopes and directions in urban studies. This paper focuses on exploring how to convert entropy measurements into fractal dimensions for the spatial analysis of scale-free urban phenomena using the ideas from scaling. Urban systems proved to be random prefractal and multifractal systems. The spatial entropy of fractal cities bears two properties. One is the scale dependence: the entropy values of urban systems always depend on the linear scales of spatial measurement. The other is entropy conservation: different fractal parts bear the same entropy value. Thus, entropy cannot reflect the simple rules of urban processes and the spatial heterogeneity of urban patterns. If we convert the generalized entropies into multifractal spectrums, the problems of scale dependence and entropy homogeneity can be solved to a degree for urban spatial analysis. Especially, the geographical analyses of urban evolution can be simplified. This study may be helpful for students in describing and explaining the spatial complexity of urban evolution.

Calculation of Organizational-Technological Tasks by Ensuring the Stability and Reliability; Erection of Multi-Storey Frame Buildings

In the article fundamentally new problems are considered - the calculation of organizational and technological tasks by ensuring the stability of multi-storey frame buildings. Multi-storey frame construction is a very complex spatial rod systems with inclusion of planar and volumetric elements from prefabricated and monolithic reinforced concrete or metal lattice systems in them and is used in almost all fields of the national economy.

Remote Sensing, Gis and Cellular Automata for Urban Growth Simulation

Cities are complex spatial systems and modeling their dynamics of growth using traditional modeling techniques is a challenging task. Cellular automata (CA) have been widely used for modeling urban growth because of their computational simplicity, their explicit representation of time and space and their ability to generate complex patterns from the interaction of simple components of the system using simple rules. Integrating GIS tools and remote sensing data with CA has the potential to provide realistic simulation of the future urban growth of cities. The proposed approach is applied to model the growth of the City of Montreal. Land use/land cover maps derived from Landsat data acquired in 1975 and 1990 were used to train a CA model which was then used to project the land use in 2005. A comparison of the projected and actual land uses for 2005 is presented and discussed.

Diagramy Voronoi – modele badawcze struktur prętowych w optymalizacji architektoniczno-konstrukcyjnej

In modern design architecture there is an interesting trend of developing highly complex spatial systems, inspired by patterns inspired by the natural world. As a result, visually innovative solutions are being created, and what is important from an engineering point of view, also technologically efficient. The logic behind shaping “bionic” architec- ture is aimed at, among others, the rational use of materials and energy. The search for new spatial structures through multi-criteria analyses has increased the interest in digital optimization issues in multidisciplinary architectural and engineering analyses. Algorithms used to form diverse, multi-variant carrier systems based on similar boundary as- sumptions play a special role in improving computer programs. Research samples in the development of regular and irregular rod-like structures based on own developed digital models have been presented as an example of such action. The simulations conducted involved analysis of configurable structures based on their efficiency in material consump- tion.