A bending moment is a measure of the internal moment that causes a beam or structural element to bend. It results from external loads applied to the beam, which create a moment about a section of the beam. The bending moment at a particular section of a beam determines how much the beam will bend (deflect) at that section.
The term "counterweight" refers to a weight that is used to balance or offset another weight. It is commonly used in various contexts, including: 1. **Mechanical Systems**: In machinery, counterweights are used to balance heavy components, such as in elevators (where a counterweight helps to counterbalance the weight of the cab) or cranes (where counterweights stabilize the structure when lifting heavy loads).
A parallel force system refers to a scenario in mechanics where two or more forces are applied to an object in the same or opposite direction along parallel lines of action. These forces act simultaneously, and they can be of different magnitudes and directions, but they do not intersect, maintaining their parallel orientation. ### Key Features of a Parallel Force System: 1. **Direction**: The forces are aligned parallel to each other, meaning they do not converge or diverge.
A three-body force refers to interactions in a physical system involving three particles or bodies, where the force on one particle depends not just on its interactions with one of the other two particles, but on the configuration and interactions involving all three bodies together. This concept is particularly relevant in fields such as nuclear physics, astrophysics, and molecular dynamics. In classical mechanics, most forces can be understood as pairwise interactions, where the force between two bodies is described independently of any third body.
In engineering, "traction" generally refers to the grip or friction between a surface and a moving object, typically wheels or tracks on rail systems, vehicles, or other machinery. It is a crucial factor in determining how well a vehicle can move, accelerate, or stop without slipping. There are several contexts in which traction is discussed: 1. **Automotive Engineering**: In vehicles, traction is essential for effective acceleration, cornering, and braking.
"Math on Trial" is a program designed to explore the intersection of mathematics and legal concepts, particularly how mathematical reasoning can be applied in legal contexts. This can involve examining cases where statistical evidence plays a critical role, analyzing probabilities, or understanding the mathematics behind forensic science. In educational settings, "Math on Trial" often takes the form of a course or workshop where students engage in mock trials, using math to support arguments, evaluate evidence, and draw conclusions.
People v. Collins is a notable case in California legal history, primarily concerning the admissibility of statistical evidence in criminal trials. The case was decided by the California Supreme Court in 1968. In this case, the defendant, Collins, was convicted of robbery based on eyewitness testimony and the use of statistical evidence to link him to the crime.
L-systems, or Lindenmayer systems, are a mathematical formalism introduced by the Hungarian botanist Aristid Lindenmayer in 1968 as a way to describe the growth processes of organisms, particularly plants. L-systems are particularly useful for modeling the branching structures of plants and other biological forms, as well as for generating fractal patterns and complex graphics.
Ambiguous grammar refers to a type of formal grammar in which a single string (or sentence) can be generated by the grammar in multiple ways, producing more than one distinct parse tree or derivation. This ambiguity means that there may be multiple interpretations or meanings associated with that string, depending on the different parse trees. In the context of programming languages and compilers, ambiguous grammars can lead to confusion and difficulties in parsing, as they do not provide a clear association between syntax and semantics.
Attribute grammar is a formalism used in the field of computer science, particularly in the design and implementation of programming languages and compilers. It extends context-free grammars by adding attributes to the grammar's symbols and defining rules for calculating these attributes. ### Key Components: 1. **Grammar**: Like a traditional context-free grammar (CFG), an attribute grammar defines a set of production rules that describe the syntactic structure of a language.
The Büchi-Elgot-Trakhtenbrot theorem is a result in the field of formal languages and automata theory, specifically concerning the expressiveness of certain types of logical systems and their relationship to automata. The theorem establishes a correspondence between regular languages and certain logical formulas, which is a significant topic in the study of the foundations of computer science, particularly in the areas of model checking and verification.
Categorical grammar is a type of formal grammar that is used in theoretical linguistics and computational linguistics. It is based on category theory, which is a branch of mathematics that deals with abstract structures and their relationships. Categorical grammars treat syntactic categories (like nouns, verbs, etc.) and constructs (like sentences) in terms of mathematical objects and morphisms (arrows) between them. In categorical grammar, the main idea is that grammatical structures can be represented as categories.
The Kleene star, denoted by the symbol \( * \), is an operation in formal language theory and automata theory used to define the set of strings that can be generated by repeatedly concatenating zero or more copies of a given set of strings.
Kuroda normal form is a specific representation of context-free grammars (CFGs) that is particularly useful in the study of parsing and formal language theory. In Kuroda normal form, a context-free grammar is structured in such a way that its production rules are constrained to a limited set of forms that can generate the same language as the original grammar but with more manageable syntax.
A context-sensitive language (CSL) is a type of formal language that is defined by a context-sensitive grammar. Context-sensitive grammars are more powerful than context-free grammars and are used to describe languages that require context to determine their grammatical structure.
A **Deterministic Context-Free Language (DCFL)** is a type of formal language that can be recognized by a deterministic pushdown automaton (DPDA). These languages are a strict subset of context-free languages and are characterized by the following features: 1. **Deterministic Parsing**: In a DPDA, for every state and input symbol (including the top of the stack), there is at most one action that can be taken.
Discontinuous-constituent phrase structure grammar (DC-PSG) is a type of grammar framework that accommodates non-contiguous constituents in the structure of sentences. In traditional phrase structure grammars, constituents are expected to be contiguous, meaning that the elements making up a phrase appear in a continuous stretch of text. However, natural language often presents constructions where constituents are separated by other elements, making it challenging to represent these structures using standard contiguous grammar models.
Terminal yield typically refers to the expected return on an investment or project at the end of a specified period, particularly in the context of real estate or agricultural investments. It can represent the final yield or return that an investor anticipates when they sell an asset or at the end of its life cycle. In different contexts: 1. **Real Estate:** Terminal yield might refer to the net operating income (NOI) produced by a property at the end of its investment horizon divided by its selling price.
Operator-precedence grammar is a type of formal grammar used primarily for parsing expressions in computer programming languages. It provides a systematic way of treating the precedence and associativity of operators, which helps determine the order in which parts of an expression are evaluated. ### Key Concepts: 1. **Operators**: These are symbols that denote operations such as addition, subtraction, multiplication, etc.
The Interchange Lemma is a concept in the field of combinatorics and graph theory, primarily associated with the study of matroid theory and combinatorial optimization. Although the term "Interchange Lemma" might refer to different specific results depending on the context, it often relates to the idea of interchanging elements in certain structures (such as sets or sequences) to achieve optimality or to prove the existence of specific properties.

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