Summation is the process of adding a sequence of numbers or expressions together to obtain a total. In mathematics, it is often represented by the summation symbol, which is the Greek letter Sigma (Σ). The process can apply to finite sets of numbers, as well as infinite series. ### Key Components of Summation 1. **Symbol**: The summation symbol (Σ) is used to indicate that a sum is being calculated.
An addition-subtraction chain is a sequence of integers that starts with a specific number and generates subsequent numbers through a series of addition and subtraction operations. The goal is often related to computing a specific integer efficiently, particularly in the context of algorithms, number theory, or computational mathematics. ### Definition An **addition-subtraction chain** involves: - Starting from an initial number, typically \( a_0 = 1 \).
Towers Watson, now known as Willis Towers Watson, is a global advisory, broking, and solutions company formed from the merger of Towers Perrin and Willis Group Holdings in 2016. The firm specializes in risk management, insurance, and human capital consulting, providing services to businesses in a variety of sectors. Willis Towers Watson offers a range of services that include employee benefits consulting, actuarial services, talent management, risk management solutions, and insurance brokerage.
Actuarial associations are professional organizations that bring together actuaries and promote the interests of the actuarial profession. These associations aim to support actuaries through professional development, certification, education, and networking opportunities. They also engage in research, set professional standards, and advocate for the ethical practice of actuarial work.
Actuaries are professionals who apply mathematical, statistical, and financial theories to assess risk and uncertainty in various industries, primarily in insurance and finance. They can be found in many countries, and their nationality varies widely. The profession is regulated differently around the world, with various actuarial organizations and institutes providing qualifications.
In category theory, an exact functor is a specific type of functor that preserves the exactness of sequences or diagrams in the context of abelian categories or exact categories. While the precise definition can depend on the context, here are some key points about exact functors: 1. **Preservation of Exact Sequences:** An exact functor \( F: \mathcal{A} \to \mathcal{B} \) between abelian categories preserves exact sequences.
In mathematics, particularly in the field of algebraic topology and homological algebra, an **exact sequence** is a sequence of algebraic objects (like groups, modules, or vector spaces) connected by morphisms (like group homomorphisms or module homomorphisms) such that the image of one morphism is equal to the kernel of the next. This concept is crucial because it encapsulates the idea of relationships between structures and helps in understanding their properties.
Vicky Neale is a British mathematician known for her work in the field of mathematical education and her research in number theory. She is a professor at the University of Oxford and is recognized for her efforts to promote mathematics to a broader audience. Neale has also been involved in several outreach initiatives aimed at encouraging students, especially young women, to pursue careers in mathematics and related fields. Additionally, she is noted for her engaging presentations and contributions to popularizing mathematics through various media.
The space industry encompasses all activities related to the design, manufacturing, launching, and operation of spacecraft and related technologies, as well as the use of space for various applications. This industry includes a wide range of sectors and activities: 1. **Satellite Manufacturing and Launch**: Development and construction of satellites for purposes such as telecommunications, weather monitoring, Earth observation, navigation, and scientific research. Launch services are provided by companies that specialize in sending satellites into orbit.
Gregory Freiman is known for his contributions to mathematics, particularly in areas related to number theory and combinatorial set theory. He has worked on topics such as additive number theory and combinatorial structures, gaining recognition for his insights and published research in these fields.
Architecture and Vision is a design studio founded by the architects Mario Cucinella and David P. C. de Meijer, known for its innovative approach to architecture and urban development. It focuses on creating sustainable, functional, and aesthetically appealing spaces that respond to environmental and cultural contexts. The studio is known for its interdisciplinary approach, integrating architecture, urban design, and landscape architecture, often leveraging advanced technology and materials to enhance design outcomes.
The Department of Aerospace Science and Technology typically refers to a division within a university or educational institution that specializes in aerospace engineering, aviation management, and related fields. Such departments focus on various aspects of aerospace systems, including the design, development, and testing of aircraft and spacecraft, as well as the analysis of their performance and safety. Programs within a Department of Aerospace Science and Technology may offer degrees in aerospace engineering, astronautics, aeronautics, or other related disciplines.
The Rijndael S-box (substitution box) is a fundamental component of the Rijndael encryption algorithm, which is the basis for the Advanced Encryption Standard (AES). The S-box is used to perform byte substitution in the cipher, replacing each byte of the input data with a corresponding byte from a predefined substitution table.
Korea Aerospace University (KAU) is a prominent educational institution located in South Korea, specifically in the city of Goyang, Gyeonggi Province. Established in 1952, KAU is recognized for its specialized focus on aerospace engineering and related fields. The university offers a range of programs at the undergraduate and graduate levels, including degrees in aerospace engineering, aviation, and other engineering disciplines.
Charles Wesley Shilling was an American author and historian, best known for his works on the history and architecture of various regions, particularly focusing on Pennsylvania and its historical significance. He often explored themes related to local history, the impact of various cultural and social movements, and the preservation of historical sites. Unfortunately, specific detailed information about his life and contributions might not be widely available, as he may not be a prominent figure in mainstream historical literature.
Carbon-fiber-reinforced polymers (CFRP) are composite materials made from a polymer matrix reinforced with carbon fibers. This combination results in a material that boasts a high strength-to-weight ratio, excellent stiffness, and enhanced durability. CFRPs are known for their lightweight properties, making them particularly advantageous in applications where reducing weight is crucial, such as in aerospace, automotive, sporting goods, and civil engineering.
Inconel is a family of high-performance alloys primarily composed of nickel, with varying amounts of chromium and iron, and often other elements such as molybdenum, niobium, and titanium. These alloys are well-known for their high strength, oxidation resistance, and ability to withstand extreme temperatures, making them ideal for use in harsh environments, such as those found in aerospace, chemical processing, oil and gas, and power generation industries.
Kapton is a brand name for a type of polyimide film developed by DuPont. It is known for its excellent thermal stability, mechanical properties, and electrical insulation capabilities. Kapton can withstand extreme temperatures, ranging from as low as -269°C (-452°F) to as high as 400°C (752°F) without significant degradation, making it suitable for various applications in extreme environments.
Project Space Track is an initiative by the United States Space Force that aims to enhance the transparency and accessibility of space data. It primarily focuses on sharing information about space objects, including satellites and debris, with a wider audience, including researchers, companies, and the general public. The project utilizes various technological platforms and data-sharing practices to provide insights into space situational awareness and promote safe and sustainable use of outer space.

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