Ubiquity is a synonym for omnipresence, the property of being present everywhere.

Ubiquity may also refer to:

Ubiquity is the default installer for Ubuntu and its derivatives. It is run from the Live CD or USB and can be triggered to run from the options on the device or on the desktop of the Live mode. It was first introduced in Ubuntu 6.06 LTS (Dapper Drake). Before it begins, it offers the user to change the language to a local language if they prefer. It is designed to be easy to use.

Features

Ubiquity consists of a configuration wizard allowing the user to easily install Ubuntu and shows a slideshow showcasing many of Ubuntu’s features while it is installing. In Ubuntu 10.10 (Maverick Meerkat), the installer team made changes to simplify the tool and speed up the installation wizard.

Ubiquity allows the user to choose the installer to automatically update the software while it's installing. If the user allows this, the installer will download the latest packages from the Ubuntu repository ensuring the system is up to date.

The installer also allows the user to set Ubiquity to install closed source or patented third party software such as Adobe Flash and Fluendo’s MP3 codec software that is commonly needed by users while Ubuntu is installing.

Hollow Earth Expedition is a pulp 1930s role-playing game set in the fictitious Hollow Earth, published by Exile Game Studio. The game has been nominated for several Origins and ENnie awards since its release in 2006.

The main rule book is Hollow Earth Expedition, and it is often abbreviated as HEX.

System

Hollow Earth Expedition uses the Ubiquity rules, which were also created by Exile Game Studio. The main feature of the system is its use of binary dice pool rolls to determine success. Under the default rules, each even number rolled counts as a success, while odd numbers count as nothing. Odd 'nothings' do not cancel out even 'successes', making dice rolling quick and simple. This binary system has also led to the development of special Ubiquity Dice, which are not detailed below.

Game setting

The surface world

Hollow Earth Expedition is set in the 1930s. On the surface, everything appears as it does in our real world history books, but if you dig a little deeper you encounter secret societies and villainous organizations, many of whom have a vested interest in the Hollow Earth.

Duality may refer to:

Mathematics

Philosophy, logic, and psychology

Science

Electrical and mechanical

In geometry a striking feature of projective planes is the symmetry of the roles played by points and lines in the definitions and theorems, and (plane) duality is the formalization of this concept. There are two approaches to the subject of duality, one through language (§ Principle of Duality) and the other a more functional approach through special mappings. These are completely equivalent and either treatment has as its starting point the axiomatic version of the geometries under consideration. In the functional approach there is a map between related geometries that is called a duality. Such a map can be constructed in many ways. The concept of plane duality readily extends to space duality and beyond that to duality in any finite-dimensional projective geometry.

Principle of Duality

A projective plane C may be defined axiomatically as an incidence structure, in terms of a set P of points, a set L of lines, and an incidence relation I that determines which points lie on which lines. These sets can be used to define a plane dual structure.

In the context of a Community of practice the notion of a duality is used to capture the idea of the tension between two opposing forces which become a driving force for change and creativity. Wenger (Wenger 1998) uses the concept of dualities to examine the forces that create and sustain a Community of Practice. He describes a duality thus: '... a single conceptual unit that is formed by two inseparable and mutually constitutive elements whose inherent tensions and complementarity give the concept richness and dynamism' (Wenger 1998, p. 66).

Some compare the concept of a duality to that of Yin and Yang, i.e. two mutually defining opposites.

The opposing entities in a duality need to be viewed from a perspective of balance rather than opposition. The term implies a dynamism, continual change and mutual adjustment as the tensions that are inherent in dualities can be both creative and constraining. (Wenger 1998) identifies four dualities that exist in Communities of Practice: participation-reification, designed-emergent, identification-negotiability and local-global.