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Open-source Tools in R for Landscape Ecology
Purpose of Review
Landscape ecology, the study of the complex interactions between landscapes and ecological processes, has hugely benefited from the increase in widely available open-source software in recent years. In particular, the
R
programming language provides a wealth of community developed tools for landscape ecology.
Recent Findings
In this paper, we examine existing packages for downloading, processing and visualisation of spatial data, as well as those specifically developed for spatial ecological analysis. Additionally, we outline the results of a survey of
R
users within the landscape ecology community.
Summary
We found that landscape ecologists are generally satisfied with the functionality available within
R
, and that as a community they are continually further developing the functionality available. Suggested future developments include improvement of computation performance; additional methods for landscape characterisation such as surface metrics; and advanced, accessible visualisation tools.
Journal Article
M-Hazy Vector Spaces over M-Hazy Field
The generalization of binary operation in the classical algebra to fuzzy binary operation is an important development in the field of fuzzy algebra. The paper proposes a new generalization of vector spaces over field, which is called M-hazy vector spaces over M-hazy field. Some fundamental properties of M-hazy field, M-hazy vector spaces, and M-hazy subspaces are studied, and some important results are also proved. Furthermore, the linear transformation of M-hazy vector spaces is studied and their important results are also proved. Finally, it is shown that M-fuzzifying convex spaces are induced by an M-hazy subspace of M-hazy vector space.
Journal Article
Multi-component and multi-phase-field modelling of solidification microstructural evolution in Inconel 625 alloy during laser powder bed fusion additive manufacturing
Inconel 625 alloy, known for exceptional mechanical properties and corrosion resistance, is widely used in aerospace, power generation, and marine applications. Laser powder bed fusion (LPBF) excels in manufacturing complex geometries with good surface finish. However, LPBF printed microstructure is highly heterogeneous due to the rapid and complex thermal cycles, necessitating careful parameter selection to prevent the stabilisation of detrimental phases. Experimental parametric optimisation of LPBF is challenging due to the cost and complex inter-playing process variables. Therefore, mathematical modelling is advantageous for optimising LPBF parameters. A 3D heat source model was developed using finite element method (FEM) to analyse thermal cycles with bed-preheating and varying laser parameters in LPBF of IN625. The model focused on a simplified thermal cycle method, where all elements in a layer were set to melt at once to reduce the computational time. A multi-phase-field method (M-PFM) was developed to simulate the microstructural evolution as a function of FEM-generated thermal boundary conditions. The morphological and elemental segregation behaviour of evolving microstructure was simulated. The dendrite morphology predicted by simulations showed strong agreement with experimental observations. The primary dendritic arm spacing (PDAS) obtained from phase-field and analytical models matched the experimental trends, validating the adapted modelling approach. The segregation and the microstructural evolution were found to be strongly influenced by the prevailing temperature gradients and the cooling rates of the melt pool, along with the peak temperatures reached during the remelting cycles.
Journal Article
Remote Sensing’s Recent and Future Contributions to Landscape Ecology
Purpose of Review
The purpose of this article is to review landscape ecology research from the past 5 years to identify past and future contributions from remote sensing to landscape ecology.
Recent Findings
Recent studies in landscape ecology have employed advances made in remote sensing. These include the use of reliable and open datasets derived from remote sensing, the availability of new sources for freely available satellite imagery, and machine-learning image classification techniques for classifying land cover types. Remote sensing data sources and methods have been used in landscape ecology to examine landscape structure. Additionally, these data sources and methods have been used to analyze landscape function including the effects of landscape structure and landscape change on biodiversity and population dynamics. Lastly, remote sensing data sources and methods have been used to analyze historical landscape changes and to simulate future landscape changes.
Summary
The ongoing integration of remote sensing analyses in landscape ecology will depend on continued accessibility of free imagery from satellite sources and open-access data-analysis software, analyses spanning multiple spatial and temporal scales, and novel land cover classification techniques that produce accurate and reliable land cover data. Continuing advances in remote sensing can help to address new landscape ecology research questions, enabling analyses that incorporate information that ranges from ground-based field samples of organisms to satellite-collected remote sensing data.
Journal Article
Almost Conformal Vector Fields on a Riemannian Manifold
We introduce the notion of an almost conformal vector field, which generalizes conformal vector fields and recently introduced m-modified conformal vector fields on a Riemannian manifold. The definition of an almost conformal vector field ζ on an n-dimensional Riemannian manifold (N,g) requires two smooth functions σ and f called the potential and copotential and a skew symmetric tensor φ called the associated tensor of ζ. Many examples of almost conformal vector fields which are not conformal vector fields are provided. We find conditions using σ, f and φ under which an almost conformal vector field ζ on an n-dimensional compact Riemannian manifold (N,g) is either conformal or a Killing vector field. We also find conditions under which a compact Riemannian manifold (N,g) admitting an almost conformal vector field is isometric to the sphere S[sup.n](c). Finally, we find conditions under which an almost conformal vector field ζ on a noncompact Riemannian manifold (N,g) is a Killing vector field.
Journal Article
The emotional challenges of conducting in-depth research into significant health issues in health geography: reflections on emotional labour, fieldwork and life course
Emotions are increasingly being recognised and integrated into human geography and it has been highlighted that focusing on the 'interrelatedness' of the research process is crucial. By contextualising fieldwork within the life course of the researcher, greater acknowledgement of the 'emotional labour' involved in fieldwork can be highlighted. The author reflects on the 'emotional geographies' of conducting PhD research into significant health issues with participants who had recently suffered a heart attack in Fife, Scotland. This paper reveals emotions involved in this kind of research, drawing on perspectives from participants as well as the researcher. The author also draws attention to, and reflects on, the lack of engagement with researcher's emotional labour within formal academic structures, such as research training and ethics application processes. Reflecting on fieldwork experiences from a distance, the author discusses the influence and impact of her emotional experiences of fieldwork. This paper contributes to work concerned with emotions and fieldwork in geography and asserts that greater importance and value needs to be given to this type of emotion work as embedded and situated within researchers' life courses.
Journal Article
On the (𝑛, 𝑚)- semirings derived polynomially from infinite semidomains
In the paper [Marichal, J.-L. and Mathonet, P., A description of n-ary semigroups polynomial-derived from integral domains, Semigroup Forum, 83 (2011), No. 2, 241-249] the authors provide a complete classification of the n-semigroups, defined by polynomial functions over infinite commutative integral domains with identity (i.e., the n-semigroup structures polynomial derived from integral domains). We remark that some results from that paper can be extended for the n-semigroups polynomial-derived defined over infinite semidomains with zerosumfree element. Furthermore, in this note we give a description of (n, m)-semiring structures defined by polynomial functions over such semidomains.
Journal Article
Application of M¨obius coordinate transformation in evaluating Newton’s integral
We propose a numerical scheme which efficiently combines various existing methods of solving the Newton’s volume integral. It utilises the analytical solution of Newton’s integral for tesseroid in computing the near-zone contribution to gravitational field quantities (potential and its first radial derivative). The far-zone gravitational contribution is computed using the expressions derived based on applying Molodensky’s truncation coefficients to a spectral representation of Newton’s integral. The weak singularity of Newton’s integral is treated analytically using formulas for the gravitational contribution of the cylindrical mass volume centered with respect to the observation point. All three solutions are defined and evaluated in the system of polar spherical coordinates. A conversion of the geographical to polar spherical coordinates of input data sets (digital terrain and density models) is based on the M¨obius transformation with an enhanced integration grid resolution at vicinity of the observation point.
Journal Article
Analysis of m ‐Modified Conformal Vector Fields on the Tangent Bundle With Synectic Lift Metrics
In this study, we introduce the notion of an m ‐modified conformal vector field, which represents a natural generalization of the classical conformal vector field concept. This extension allows for a broader class of vector fields that conform to modified transformation rules under conformal changes in geometry. Specifically, we explore the necessary and sufficient conditions under which the vector fields V V , C V , C V + γ F , and V u (also known as the Liouville vector field) qualify as m ‐modified conformal vector fields within the framework of the synectic lift metric on the tangent bundle. The investigation into these conditions requires careful analysis using geometric tools and algebraic methods. In our calculations, we employ an adapted frame, which significantly streamlines the computations and provides multiple advantages for the geometric interpretations. Through this approach, we are able to derive deeper insights into the structure of these vector fields and their role within the broader context of differential geometry.
Journal Article