Download or read book Dynamic Factor Trees and Forests written by Daniel Wochner and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Machine Learning models are often considered to be "black boxes" that provide only little room for the incorporation of theory (cf. e.g. Mukherjee, 2017; Veltri, 2017). This article proposes so-called Dynamic Factor Trees (DFT) and Dynamic Factor Forests (DFF) for macroeconomic forecasting, which synthesize the recent machine learning, dynamic factor model and business cycle literature within a unified statistical machine learning framework for model-based recursive partitioning proposed in Zeileis, Hothorn and Hornik (2008). DFTs and DFFs are non-linear and state-dependent forecasting models, which reduce to the standard Dynamic Factor Model (DFM) as a special case and allow us to embed theory-led factor models in powerful tree-based machine learning ensembles conditional on the state of the business cycle. The out-of-sample forecasting experiment for short-term U.S. GDP growth predictions combines three distinct FRED-datasets, yielding a balanced panel with over 375 indicators from 1967 to 2018 (FRED, 2019; McCracken & Ng, 2016, 2019a, 2019b). Our results provide strong empirical evidence in favor of the proposed DFTs and DFFs and show that they significantly improve the predictive performance of DFMs by almost 20% in terms of MSFE. Interestingly, the improvements materialize in both expansionary and recessionary periods, suggesting that DFTs and DFFs tend to perform not only sporadically but systematically better than DFMs. Our findings are fairly robust to a number of sensitivity tests and hold exciting avenues for future research.
Download or read book Dynamic Factor Trees and Forests written by Daniel Ehmann and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Machine Learning models are often considered to be "black boxes" that provide only little room for the incorporation of theory (cf. e.g. Mukherjee, 2017; Veltri, 2017). This article proposes so-called Dynamic Factor Trees (DFT) and Dynamic Factor Forests (DFF) for macroeconomic forecasting, which synthesize the recent machine learning, dynamic factor model and business cycle literature within a unified statistical machine learning framework for model-based recursive partitioning proposed in Zeileis, Hothorn and Hornik (2008). DFTs and DFFs are non-linear and state-dependent forecasting models, which reduce to the standard Dynamic Factor Model (DFM) as a special case and allow us to embed theory-led factor models in powerful tree-based machine learning ensembles conditional on the state of the business cycle. The out-of-sample forecasting experiment for short-term U.S. GDP growth predictions combines three distinct FRED-datasets, yielding a balanced panel with over 375 indicators from 1967 to 2018 (FRED, 2019; McCracken & Ng, 2016, 2019a, 2019b). Our results provide strong empirical evidence in favor of the proposed DFTs and DFFs and show that they significantly improve the predictive performance of DFMs by almost 20% in terms of MSFE. Interestingly, the improvements materialize in both expansionary and recessionary periods, suggesting that DFTs and DFFs tend to perform not only sporadically but systematically better than DFMs. Our findings are fairly robust to a number of sensitivity tests and hold exciting avenues for future research.
Download or read book Forest Dynamics written by Daniel B. Botkin and published by . This book was released on 1993 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering a fresh perspective on ecological phenomena, this book provides all the information necessary to understand and use the JABOWA simulation model of forest growth. It sets the forest model within the broader context of the science of ecology and the ecological issues that confront society in the management of forests.
Download or read book Models of Tree and Stand Dynamics written by Annikki Mäkelä and published by Springer Nature. This book was released on 2020-03-17 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is designed to be a textbook for university students (MSc-PhD level) and a reference for researchers and practitioners. It is an introduction to dynamic modelling of forest growth based on ecological theory but aiming for practical applications for forest management under environmental change. It is largely based on the work and research findings of the authors, but it also covers a wide range of literature relevant to process-based forest modelling in general. The models presented in the book also serve as tools for research and can be elaborated further as new research findings emerge. The material in the book is arranged such that the student starts from basic concepts and formulations, then moves towards more advanced theories and methods, finally learning about parameter estimation, model testing, and practical application. Exercises with solutions and hands-on R-code are provided to help the student digest the concepts and become proficient with the methods. The book should be useful for both forest ecologists who want to become modellers, and for applied mathematicians who want to learn about forest ecology. The basic concepts and theory are formulated in the first four chapters, including a review of traditional descriptive forest models, basic concepts of carbon balance modelling applied to trees, and theories and models of tree and forest structure. Chapter 5 provides a synthesis in the form of a core model which is further elaborated and applied in the subsequent chapters. The more advanced theories and methods in Chapters 6 and 7 comprise aspects of competition through tree interactions, and eco-evolutionary modelling, including optimisation and game theory, a topical and fast developing area of ecological modelling under climate change. Chapters 8 and 9 are devoted to parameter estimation and model calibration, showing how empirical and process-based methods and related data sources can be bridged to provide reliable predictions. Chapter 10 demonstrates some practical applications and possible future development paths of the approach. The approach in this book is unique in that the models presented are based on ecological theory and research findings, yet sufficiently simple in structure to lend themselves readily to practical application, such as regional estimates of harvest potential, or satellite-based monitoring of growth. The applicability is also related to the objective of bridging empirical and process-based approaches through data assimilation methods that combine research-based ecological measurements with standard forestry data. Importantly, the ecological basis means that it is possible to build on the existing models to advance the approach as new research findings become available.
Download or read book Plant Biomechanics written by Anja Geitmann and published by Springer. This book was released on 2018-06-09 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides important insights into the operating principles of plants by highlighting the relationship between structure and function. It describes the quantitative determination of structural and mechanical parameters, such as the material properties of a tissue, in correlation with specific features, such as the ability of the tissue to conduct water or withstand bending forces, which will allow advanced analysis in plant biomechanics. This knowledge enables researchers to understand the developmental changes that occur in plant organs over their life span and under the influence of environmental factors. The authors provide an overview of the state of the art of plant structure and function and how they relate to the mechanical behavior of the organism, such as the ability of plants to grow against the gravity vector or to withstand the forces of wind. They also show the sophisticated strategies employed by plants to effect organ movement and morphogenesis in the absence of muscles or cellular migration. As such, this book not only appeals to scientists currently working in plant sciences and biophysics, but also inspires future generations to pursue their own research in this area.
Download or read book Nature of Computation and Communication written by Cong Vinh Phan and published by Springer Nature. This book was released on 2023-03-23 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed post-conference proceedings of the 8th EAI International Conference on Nature of Computation and Communication, ICTCC 2022, held in Vinh Long, Vietnam, in October 27-28 2022. The 11 revised full papers presented were carefully selected from 32 submissions. The papers of ICTCC 2022 cover formal methods for self-adaptive systems and discuss natural approaches and techniques for natural computing systems and their applications.
Download or read book Forest Dynamics Growth and Yield written by Hans Pretzsch and published by Springer Science & Business Media. This book was released on 2009-06-19 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to improve the understanding of forest dynamics and the sustainable management of forest ecosystems. How do tree crowns, trees or entire forest stands respond to thinning in the long term? What effect do tree species mixtures and multi-layering have on the productivity and stability of trees, stands or forest enterprises? How do tree and stand growth respond to stress factors such as climate change or air pollution? Furthermore, in the event that one has acquired knowledge about the effects of thinning, mixture and stress, how can one make that knowledge applicable to decision-making in forestry practice? The experimental designs, analytical methods, general relationships and models for answering questions of this kind are the focus of this book. Given the structures dealt with, which range from plant organs to the tree, stand and enterprise levels, and the processes analysed in a time frame of days or months to decades or even centuries, this book is directed at all readers interested in trees, forest stands and forest ecosystems. This work has been compiled for students, scientists, lecturers, forest planners, forest managers, and consultants.
Download or read book Forest Entomology written by William Ciesla and published by John Wiley & Sons. This book was released on 2011-03-08 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insects are the most abundant and diverse organisms that inhabit our planet and are found in all the world’s forest ecosystems. Many feed and/or breed on parts of trees. Some perform important functions, such as pollination or break-down of dead vegetation. Others weaken, deform or kill trees, and compete with humans for the many goods and services that trees and forests provide. Forest Entomology: A Global Perspective examines forest insects in a global context and reviews their dynamics, interactions with humans and methods for monitoring and management of species that damage forests. Also provided are 235 profiles of forest insects, worldwide. A series of tables provides summaries of the distribution and hosts of many more species. Included are those that damage forests, others that are simply curiosities and some that are beneficial. This book is designed as a reference for students, practicing foresters and forest health specialists, especially for those who work internationally or are concerned with species that have the potential to expand their ranges via international trade, travel or environmental changes.
Download or read book The Forests Handbook Volume 1 written by Julian Evans and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: The future of the world's forests is at the forefront of environmental debate. Rising concerns over the effects of deforestation and climate change are highlighting the need both to conserve and manage existing forests and woodland through sustainable forestry practices. The Forests Handbook, written by an international team of both scientists and practitioners, presents an integrated approach to forests and forestry, applying our present understanding of forest science to management practices, as a basis for achieving sustainability. Volume One presents an overview of the world's forests; their locations and what they are like, the science of how they operate as complex ecosystems and how they interact with their environment. Volume Two applies this science to reality; it focuses on forestry interventions and their impact, the principles governing how to protect forests and on how we can better harness the enormous benefits forests offer. Case studies are drawn from several different countries and are used to illustrate the key points. Development specialists, forest managers and those involved with land and land-use will find this handbook a valuable and comprehensive overview of forest science and forestry practice. Researchers and students of forestry, biology, ecology and geography will find it equally accessible and useful.
Download or read book Forest Stand Dynamics written by Chadwick D. Oliver and published by . This book was released on 1996-02-02 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive book describes the various growth patterns of forests. The purpose is to help silviculturalists and forest managers understand and anticipate how forests grow and respond to intentional manipulations and natural disasters.
Download or read book Flathead National Forest N F Hungry Horse Ranger District Middle Fork Ecosystem Management Project written by and published by . This book was released on 1994 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contaminated Forests written by Igor Linkov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concentrations of pollutants in the atmosphere have increased dramatically over the last century and many of these changes are attributable to anthropogenic activities. The influence of acid rain has been well studied, but there has been no extensive exploration of other pollutants, such as toxic chemicals, heavy metals and radionuclides. Natural ecosystems, especially forests, tend to accumulate many of these pollutants which subsequently can affect ecosystem health. These contaminants may be very damaging to the environment in Eastern Europe, where the rapid disappearance of forest is the result not only of contamination but also of poor forest management practices. The current book is designed to reduce the uncertainty in our current knowledge of forest radioecology. The three topics it embraces are (a) Modelling, (b) Measurements and Data, and (c) Countermeasures and Risk Assessment.
Download or read book The Sustainable Role of the Tree in Environmental Protection Technologies written by Edita Baltrėnaitė and published by Springer. This book was released on 2016-02-13 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph describes ways of using trees and their byproducts in environmental protection technologies and methodologies throughout their lifecycles. The tree, the planet’s main source of biomass, is an indispensable tool for sustainable technologies, and the authors present a holistic picture of how and why in this volume. The authors describe the indispensable role of the living tree in phytoremediation and biomonitoring and detail the relationship of the tree with its surrounding ecosystem. The direct and indirect relationships of a tree at its vegetation period with various components of the ecosystem (i.e. atmosphere, hydrosphere, lithosphere and soil) contribute to the role of a tree as the medium for integrating aerogenic and edaphic pollutants. Trees phytostabilize pollutants in their organisms and remove them from the soil. The ability of some species of trees to reflect the quality of the environment makes a basis for the environmental bioindication, while quantitative representation of the chemical composition of the surrounding environment allows for the use of trees in biomonitoring. Morphological features of trees (e.g. annual tree rings) allow us to observe environmental conditions in the past and retrospectively evaluate them. This monograph also details how wood products (e.g. biochar, chips, bark, etc.) of a tree after it has died are used in environmental technologies. Due to the specific morphological form and physical and chemical composition of wood products, they may be used as active materials in the technologies aimed at reducing pollution in an effective and sustainable manner.
Download or read book Stand dynamics in a logged and silviculturally treated Costa Rican rain forest 1988 1996 written by and published by Bib. Orton IICA / CATIE. This book was released on with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Forest Worker written by and published by . This book was released on 1927 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temporal and spatial patterns of vegetation dynamics written by J. Miles and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Routledge Handbook of Forest Ecology written by Kelvin S.-H. Peh and published by Taylor & Francis. This book was released on 2024-10-07 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Routledge Handbook of Forest Ecology is an essential resource covering all aspects of forest ecology from a global perspective. This new edition has been fully revised and updated throughout to reflect the profound and unprecedented changes in both forests and climates since the publication of the first edition in 2015. The handbook reflects key developments in the field of forest dynamics and large-scale processes, as well as the changes that are now manifesting in different types of forests across the globe as a result of climate change. It covers both natural and managed forests, from boreal, temperate, sub-tropical and tropical regions of the world. In this second edition, the breadth of the handbook has been expanded with new chapters on mountain forests, monodominance, pathogens and invertebrate pests and amphibians and reptiles in forest ecosystems. Original author teams are complemented by the addition of new authors to offer fresh perspectives, and the second edition places greater emphasis on the applicability of each topic at a global level. The handbook is divided into seven parts: • Part I: The forest • Part II: Forest dynamics • Part III: Forest flora and fauna • Part IV: Energy and nutrients • Part V: Forest conservation and management • Part VI: Forest and climate change • Part VII: Human ecology The Routledge Handbook of Forest Ecology is an essential reference text for a wide range of students and scholars of ecology, environmental science, forestry, geography and natural resource management.
