BorderBorders are usually defined as geographical boundaries, imposed either by features such as oceans and terrain, or by political entities such as governments, sovereign states, federated states, and other subnational entities. Political borders can be established through warfare, colonization, or mutual agreements between the political entities that reside in those areas; the creation of these agreements is called boundary delimitation.
Letter caseLetter case is the distinction between the letters that are in larger uppercase or capitals (or more formally majuscule) and smaller lowercase (or more formally minuscule) in the written representation of certain languages. The writing systems that distinguish between the upper- and lowercase have two parallel sets of letters: each in the majuscule set has a counterpart in the minuscule set. Some counterpart letters have the same shape, and differ only in size (e.g. {C,c} or {S,s}), but for others the shapes are different (e.
Open borderAn open border is a border that enables free movement of people (and often of goods) between jurisdictions with no restrictions on movement and is lacking substantive border control. A border may be an open border due to intentional legislation allowing free movement of people across the border (de jure), or a border may be an open border due to a lack of legal controls, a lack of adequate enforcement or adequate supervision of the border (de facto).
Inertial frame of referenceIn classical physics and special relativity, an inertial frame of reference (also called inertial space, or Galilean reference frame) is a frame of reference not undergoing any acceleration. It is a frame in which an isolated physical object—an object with zero net force acting on it—is perceived to move with a constant velocity or, equivalently, it is a frame of reference in which Newton's first law of motion holds.
Chinese charactersChinese characters are logograms developed for the writing of Chinese. Chinese characters are the oldest continuously used system of writing in the world. By virtue of their widespread current use throughout East Asia and Southeast Asia, as well as their profound historic use throughout the Sinosphere, Chinese characters are among the most widely adopted writing systems in the world by number of users. The total number of Chinese characters ever to appear in a dictionary is in the tens of thousands, though most are graphic variants, were used historically and passed out of use, or are of a specialized nature.
Euler methodIn mathematics and computational science, the Euler method (also called the forward Euler method) is a first-order numerical procedure for solving ordinary differential equations (ODEs) with a given initial value. It is the most basic explicit method for numerical integration of ordinary differential equations and is the simplest Runge–Kutta method. The Euler method is named after Leonhard Euler, who first proposed it in his book Institutionum calculi integralis (published 1768–1870).
Visual acuityVisual acuity (VA) commonly refers to the clarity of vision, but technically rates a person's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye influence the sharpness of an image on its retina. Neural factors include the health and functioning of the retina, of the neural pathways to the brain, and of the interpretative faculty of the brain. The most commonly referred-to visual acuity is distance acuity or far acuity (e.g.
Initial and terminal objectsIn , a branch of mathematics, an initial object of a C is an object I in C such that for every object X in C, there exists precisely one morphism I → X. The notion is that of a terminal object (also called terminal element): T is terminal if for every object X in C there exists exactly one morphism X → T. Initial objects are also called coterminal or universal, and terminal objects are also called final. If an object is both initial and terminal, it is called a zero object or null object.
Block lettersBlock letters (known as printscript, manuscript, print writing or ball and stick in academics) are a sans-serif (or "gothic") style of writing Latin script in which the letters are individual glyphs, with no joining. Elementary education in English-speaking countries typically introduces children to the literacy of handwriting using a method of block letters (commonly referred to as manuscript by educators), which may later advance to cursive (joined) penmanship.
Frame of referenceIn physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system whose origin, orientation, and scale are specified by a set of reference points―geometric points whose position is identified both mathematically (with numerical coordinate values) and physically (signaled by conventional markers). For n dimensions, n + 1 reference points are sufficient to fully define a reference frame.
