Tonelli's theorem is a result in measure theory that provides conditions under which the order of integration can be interchanged. It is particularly useful in the context of functional analysis and real analysis when dealing with multiple integrals. The theorem typically states the following: Let \( f: X \times Y \to \mathbb{R} \) be a non-negative measurable function defined on the product measure space \( X \) and \( Y \).
A Markov Decision Process (MDP) is a mathematical framework used to model decision-making in situations where the outcomes are partly random and partly under the control of a decision maker. MDPs are widely used in fields like operations research, economics, robotics, and artificial intelligence, especially for reinforcement learning problems. An MDP is defined by the following components: 1. **States (S)**: A finite set of states that represent the possible situations in which an agent can find itself.
A byte is a unit of digital information that commonly consists of eight bits. Bits are the smallest unit of data in computing and digital communications and can represent a value of either 0 or 1. Therefore, a byte can represent 256 different values (from 0 to 255), which is useful for encoding a wide variety of data types, such as characters, numbers, and other forms of information.
A "hextet" refers to a group or set of six items or elements, often used in various contexts. While it's not a widely recognized term like "duet" (for two) or "quartet" (for four), it can be applied in different fields. Here are a couple of contexts in which "hextet" may be used: 1. **Music**: In musical terminology, a hextet would denote a group of six musicians or singers performing together.
A megabit (Mb) is a unit of digital information or computer storage that is equal to one million bits. It is commonly used to measure data transfer rates in networking, internet speeds, and file sizes. In more technical terms: - 1 megabit = 1,000,000 bits (using the decimal system, which is commonly used in telecommunications).
The Crowther criterion is a concept used in the field of statistical inference, specifically in the context of estimating the parameters of a probability distribution. This criterion helps in determining the efficiency of an estimator based on the ratio of variances of the estimator to the variance of a more efficient estimator. In more specific terms, the Crowther criterion offers a way to compare the efficiency of different estimation procedures by considering the properties of the estimators, such as their bias and variance.
Eberhard Voit is a notable figure in the field of systems biology and bioinformatics, known for his contributions to the understanding of metabolic networks and dynamic systems in biological contexts. He has authored or co-authored numerous research papers and possibly books related to mathematical modeling, systems theory, and the analysis of biological systems. Voit’s work often involves the application of mathematical and computational techniques to study complex biological processes and their underlying mechanisms.
Godfrey Hounsfield was a British electrical engineer and computer scientist who is best known for his pioneering work in the development of computed tomography (CT) scanning. Born on August 28, 1919, and passing away on August 12, 2014, Hounsfield made significant contributions to medical imaging technology. In the early 1970s, he developed the first practical CT scanner, which allowed for the detailed visualization of internal structures of the body.
Multiscale tomography is an advanced imaging technique that enables the analysis of structures across different spatial scales. It integrates data from various imaging modalities or resolutions to provide a comprehensive view of an object, such as biological tissues, materials, or other complex systems. This approach is particularly useful in fields like medical imaging, materials science, and geophysics, where information at multiple scales can lead to better understanding and diagnostics.
Xenon-enhanced CT scanning is an imaging technique that utilizes xenon gas to improve the assessment of pulmonary blood flow and ventilation in the lungs during a computed tomography (CT) scan. This technique is particularly useful for evaluating lung conditions, such as pulmonary embolism, lung tumors, and chronic obstructive pulmonary disease (COPD). The process typically involves inhaling xenon gas, which is a contrast agent that enhances the visibility of blood flow in the lungs during the CT scan.
David Fell is a biochemist known for his work in systems biology, particularly in the field of metabolic engineering and the study of metabolic networks. He has contributed to understanding how biological systems operate at a metabolic level and has been involved in research that links biochemistry with computational modeling. His work often emphasizes the application of systems approaches to study cellular metabolism and the development of strategies for metabolic modification in microorganisms for biotechnology purposes.
In the context of topology, a **ringed space** is a mathematical structure that consists of a topological space along with a sheaf of rings defined over that space. More formally, a ringed space is defined as a pair \( (X, \mathcal{O}_X) \), where: 1. \( X \) is a topological space. 2. \( \mathcal{O}_X \) is a sheaf of rings on \( X \).
A metre (or meter) is the base unit of length in the International System of Units (SI). It is defined as the distance that light travels in a vacuum in 1/299,792,458 seconds. This definition has been in place since 1983, and it reflects a fundamental constant of nature, making it a highly precise standard for measurement.
As of my last knowledge update in October 2021, I do not have any specific information about an individual named Shandelle Henson. It's possible that she could be a private individual, a newly emerging public figure, or involved in a specific context or field that hasn't gained widespread recognition.
Herbert M. Sauro is a notable figure in the field of systems biology, particularly known for his contributions to computational modeling and simulation of biological systems. He has been involved in the development of tools and software for modeling biochemical networks, including significant work on the BioNetGen software, which is used for simulating and analyzing biological systems at the molecular level. Sauro is also known for his academic work, including teaching and mentoring students in the fields of biology, computer science, and engineering.
Humberto Maturana (1928–2021) was a Chilean biologist and philosopher best known for his work in the fields of cognitive science, biology, and the philosophy of science. He is often recognized for his contributions to the understanding of living systems and cognition. Along with his colleague Francisco Varela, he developed the concept of autopoiesis, which describes the self-referential and self-maintaining nature of living organisms.
Walter M. Elsasser (1904–1991) was a prominent German-American physicist known for his work in various fields, including biophysics, geophysics, and the foundational aspects of biology and evolution. He is particularly recognized for his contributions to the understanding of the physical principles underlying biological processes. Elsasser's most notable work includes developing concepts related to the physical basis of life and proposing theories that integrate scientific principles across different domains, including physics and biology.
Fitness-density covariance is a concept from evolutionary biology, particularly in the study of population genetics and the dynamics of natural selection. It refers to the relationship between the fitness of individuals in a population and the density (or frequency) of those individuals in a phenotypic or genotypic space. ### Key Concepts: 1. **Fitness**: This refers to an individual's ability to survive and reproduce in a given environment. Higher fitness means a greater likelihood of contributing offspring to the next generation.
The Unified Neutral Theory of Biodiversity (UNTB) is an ecological theory that combines aspects of biodiversity and community ecology, focusing on the roles of competition, ecological drift, and dispersal in shaping species diversity and community composition. Developed by ecological theorist Stephen P.
Itô's lemma is a fundamental result in stochastic calculus, which is used to analyze the behavior of stochastic processes, particularly those modeled by Itô processes. Itô's lemma provides a way to differentiate functions of stochastic processes, similar to how the chain rule is applied in standard calculus.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact