Walter Whiteley is a prominent mathematician known for his contributions to the field of geometry, particularly in the area of algebraic geometry and its applications. He has worked on various topics, including the study of curves, surfaces, and their properties. Additionally, he has made significant contributions to mathematics education and has been involved in research related to mathematical thinking and pedagogy.

In geometry, a "sagitta" refers to the vertical distance from the midpoint of a chord of a circle to the arc itself. Essentially, it is the length of the line segment that is perpendicular to the chord and extends upward to meet the arc of the circle.

The term "normal fan" can have different meanings depending on the context. Here are a few possible interpretations: 1. **General Definition**: A "normal fan" could simply refer to a standard electric fan used for cooling or ventilation in homes or offices. These fans typically have blades that rotate to circulate air and are available in various types, such as ceiling fans, floor fans, and table fans.

The Axiom of Global Choice is a concept in set theory, specifically in the context of the foundations of mathematics. It can be understood as a generalization of the Axiom of Choice. The Axiom of Choice states that given a collection of non-empty sets, it is possible to select exactly one element from each set, even if there is no explicit rule for making the selection.

Slewing can refer to different concepts depending on the context, but generally, it involves a gradual change or shift in position or orientation. Here are a few contexts in which the term is commonly used: 1. **In Astronomy**: Slewing refers to the movement of a telescope or an astronomical instrument as it adjusts its position to track celestial objects. This is particularly important in tracking moving objects like planets, comets, and satellites.

In the context of differential geometry and topology, "maps of manifolds" typically refers to smooth or continuous functions that associate points from one manifold to another. Manifolds themselves are mathematical structures that generalize the concept of curves and surfaces to higher dimensions. They can be thought of as "locally Euclidean" spaces, meaning that around any point in a manifold, one can find a neighborhood that looks like Euclidean space.

The mapping class group is an important concept in the field of algebraic topology, particularly in the study of surfaces and their automorphisms. Specifically, it is the group of isotopy classes of orientation-preserving diffeomorphisms of a surface. Here's a more detailed explanation: 1. **Surface**: A surface is a two-dimensional manifold, which can be either compact (like a sphere, torus, or more complex shapes) or non-compact.

Alexander's trick is a technique used in topology, specifically in the study of continuous functions and compactness. It is primarily associated with the construction of continuous maps and the extension of functions. The trick is named after the mathematician James W. Alexander II and is often employed in scenarios where one needs to extend continuous functions from a subspace to a larger space.

The Blaschke selection theorem is a result in complex analysis and functional analysis concerning the behavior of sequences of Blaschke products, which are a type of analytic function associated with a sequence of points in the unit disk in the complex plane.

The Nielsen realization problem is a concept in the field of algebraic topology and group theory, specifically concerning the study of free groups and their automorphisms. More formally, it deals with the conditions under which a given group presentation can be realized as the fundamental group of a topological space, usually a certain type of surface or manifold.

A piecewise linear manifold is a type of topological space that is composed of a finite number of linear pieces or segments, which are pieced together in such a way that the overall structure preserves some properties of linearity.

Link distance generally refers to the minimum number of edges (or links) that must be traversed to get from one node (or vertex) to another in a graph. It's a fundamental concept in graph theory, which is widely used in various fields such as computer networking, social network analysis, and transportation systems. In a more specific context, link distance can have different meanings: 1. **In Computer Networking:** It refers to the number of hops or links between two nodes in a network.

Mori Dream Space is a conceptual space that embodies elements of Mori Girl aesthetics and culture. The "Mori Girl" style originated in Japan and is characterized by a whimsical, rustic, and nature-inspired look. This aesthetic often includes layered clothing, soft and flowing fabrics, and earthy colors, evoking a sense of tranquility and connection to nature.

"Slam Dunk" can refer to a couple of different things, primarily in the context of sports and popular culture: 1. **Basketball Move**: In basketball, a "slam dunk" is a high-impact shot where a player jumps and scores by putting the ball directly through the hoop with one or both hands. It is often considered one of the most exciting plays in basketball due to its athleticism and flair.

Symplectic filling is a concept from the field of symplectic geometry, a branch of differential geometry. It particularly deals with the relationship between contact manifolds and symplectic manifolds. A **contact manifold** is a type of manifold equipped with a contact form, which is a differential form that gives rise to a hyperplane distribution on the manifold. The simplest example of a contact manifold is the 3-dimensional sphere with the standard contact structure.

As of my last update in October 2023, "Trigenus" does not refer to any widely recognized concept, organization, brand, or term in common knowledge. It's possible that it could be a name used in a specific context, such as a business, a product, a fictional entity, or a term within a niche field.

Camera auto-calibration refers to a process or technique used to determine the intrinsic and extrinsic parameters of a camera system automatically, without requiring a detailed calibration object or manual intervention. This process is particularly useful in computer vision and robotics, as accurate camera calibration is crucial for applications like 3D reconstruction, augmented reality, and visual odometry. ### Key Concepts of Camera Auto-Calibration 1.

The correspondence problem generally refers to a situation in which the goal is to match or pair elements from two sets based on some criteria, despite the possibility of noise, occlusion, or other complicating factors. This concept comes up in various fields, including: 1. **Computer Vision**: In visual processing, the correspondence problem often involves determining which features in one image correspond to features in another image.