NAVAREA, short for "Navigation Areas," refers to maritime regions established for the purpose of disseminating navigational warning information and ensuring safe navigation. These areas are part of a global system used to provide mariners with vital information regarding hazards, changes in navigation aids, and other pertinent navigational details. The world is divided into specific NAVAREA regions, each managed by a designated country or organization responsible for issuing navigational warnings and information to vessels operating within that area.
Roteiro, in the context of navigation, refers to a detailed plan or route outline that guides the passage of a vessel from one point to another. It includes information such as waypoints, distances, estimated times of arrival, navigational aids, and any potential hazards or landmarks. This document serves as a crucial tool for mariners to ensure safe and efficient navigation over bodies of water, whether it be for recreational boating, commercial shipping, or fishing activities.
The Sagres School, known in Portuguese as "Escola de Sagres," was an important educational institution and center for maritime exploration founded in the 15th century in Portugal. It is often associated with Prince Henry the Navigator (Infante Dom Henrique), who played a key role in the early days of the Portuguese Age of Discovery. Located near the coastal town of Sagres in the Algarve, the school did not have formal classrooms in the modern sense.
In navigation, particularly in the context of spacecraft and aircraft, a **state vector** is a mathematical representation that encompasses the position and velocity of an object in space at a specific point in time. The state vector provides all the necessary information for determining the future motion of the object under the influence of forces acting upon it.
The United States Coast Pilot is a series of publications that provide detailed navigation information for U.S. coastal waters, including harbors, rivers, and other inland waterways.
In the context of mechanism design and economics, a **prior-independent mechanism** refers to a type of mechanism (or auction) that does not rely on the prior beliefs or distributions about the types of the agents participating in the mechanism. This contrasts with traditional mechanism design, where the optimal design often depends on the knowledge of the agents' types or their valuations, which are usually modeled as drawn from some known probability distribution. **Key Characteristics of Prior-Independent Mechanisms:** 1.
The Fréchet mean is a generalization of the arithmetic mean concept to more abstract spaces, particularly in the context of metric spaces or Riemannian manifolds. It is used in statistics and geometry to find a central point of a distribution of points, taking into account the geometry of the underlying space.
A multiplicative function is a type of arithmetic function that has a specific property concerning the values it takes on divisors of integers. Specifically, a function \( f \) defined on the positive integers is said to be multiplicative if it satisfies the following two conditions: 1. **Base Case**: \( f(1) = 1 \).
A multiplication table is a mathematical table used to define a multiplication operation for an algebraic system. It typically shows the products of pairs of numbers, often arranged in a grid format. For example, a basic multiplication table for numbers 1 through 10 shows each number multiplied by every other number in that range.
In mathematics, the term "product" refers to the result of multiplying two or more numbers or mathematical expressions together. The most common context in which the term is used is in arithmetic, where the product of two numbers \(a\) and \(b\) is denoted as \(a \times b\) (or simply \(ab\)).
Tsinghua Bamboo Slips refer to an ancient manuscript discovered in 2008 at Tsinghua University in Beijing, China. The manuscript consists of a collection of bamboo strips that were used for writing during the Warring States period (approximately 475-221 BCE). The bamboo slips contain texts on various subjects, including philosophical ideas, historical records, and possibly administrative documents.
Vector multiplication refers to operations that combine two or more vectors in mathematics and physics. There are two primary types of vector multiplication: the dot product and the cross product. ### 1. Dot Product (Scalar Product) The dot product of two vectors produces a scalar (a single number).
The Bagnold number (Bg) is a dimensionless quantity used in geophysics and engineering, particularly in the study of granular flows and sediment transport. It relates the inertial forces to the gravitational forces acting on a granular material or sediment.
The Ericksen number (Er) is a dimensionless number used in the study of liquid crystals and certain types of complex fluids. It characterizes the relative importance of elastic effects to viscous effects in the behavior of liquid crystalline materials. The Ericksen number is defined as the ratio of characteristic time scales, specifically the time scale associated with the elastic deformation of the liquid crystal to the time scale associated with viscous flow.
The Nelson Complexity Index (NCI) is a numerical measure used in the field of process engineering, particularly in the context of evaluating and ranking the complexity of refinery configurations. Developed by Dr. Robert Nelson, the index is primarily used to assess the complexity of refining processes based on the range of conversion capacities and types of processes included within a refining operation. The NCI is derived from the types of equipment and processing capabilities present in a refinery.
Supersonic airfoils are specially designed wings or blade shapes optimized for flight at supersonic speeds, which are defined as speeds greater than the speed of sound (Mach 1). When operating in this regime, the airflow around the airfoil becomes compressible, and several unique aerodynamic phenomena arise. ### Key Characteristics of Supersonic Airfoils: 1. **Shock Waves**: At supersonic speeds, shock waves form around the airfoil.
The term "West number" can refer to different concepts depending on the context, but it is most commonly associated with a mathematical concept or a specific function within various fields. In mathematics, it might not be a widely recognized term, and it could refer to different things depending on the area of study (like statistics, graph theory, etc.).
A centered pentagonal number is a specific figurate number that represents a centered pentagon. It can be calculated using the formula: \[ C(n) = \frac{3n(n - 1)}{2} + 1 \] where \(C(n)\) is the nth centered pentagonal number and \(n\) is a positive integer representing the position in the sequence.
A square pyramidal number is a figurate number that represents the total number of stacked squares in a pyramid with a square base. The \(n\)-th square pyramidal number counts the number of squares in a pyramid that has \(n\) layers, where the bottom layer is \(n \times n\) and each layer above decreases by 1 in both dimensions until the top layer, which is \(1 \times 1\).
Floristic Quality Assessment (FQA) is a scientific method used to evaluate the ecological quality of plant communities based on their floristic composition. This approach is often employed in conservation biology, ecology, and land management to assess the health and integrity of ecosystems, particularly wetlands, prairies, and other natural habitats. The key components of FQA include: 1. **Indicator Species**: Species are assigned a "Coefficient of Conservatism" (C value), which reflects their tolerance to disturbance.

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