Dipole antennaIn radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. A dipole antenna commonly consists of two identical conductive elements such as metal wires or rods.
Open-source governanceOpen-source governance (also known as open governance and open politics) is a political philosophy which advocates the application of the philosophies of the open-source and open-content movements to democratic principles to enable any interested citizen to add to the creation of policy, as with a wiki document. Legislation is democratically opened to the general citizenry, employing their collective wisdom to benefit the decision-making process and improve democracy. Theories on how to constrain, limit or enable this participation vary.
Docking and berthing of spacecraftDocking and berthing of spacecraft is the joining of two space vehicles. This connection can be temporary, or partially permanent such as for space station modules. Docking specifically refers to joining of two separate free-flying space vehicles. Berthing refers to mating operations where a passive module/vehicle is placed into the mating interface of another space vehicle by using a robotic arm. Because the modern process of un-berthing requires more crew labor and is time-consuming, berthing operations are unsuited for rapid crew evacuations in the event of an emergency.
Open textbookAn open textbook is a textbook licensed under an open license, and made available online to be freely used by students, teachers and members of the public. Many open textbooks are distributed in either print, e-book, or audio formats that may be downloaded or purchased at little or no cost. Part of the broader open educational resources movement, open textbooks increasingly are seen as a solution to challenges with traditionally published textbooks, such as access and affordability concerns.
Antenna (radio)In radio engineering, an antenna (American English) or aerial (British English) is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified.
Open-source licenseOpen-source licenses facilitate free and open-source software (FOSS) development. Intellectual property (IP) laws restrict the modification and sharing of creative works. Free and open-source software licenses use these existing legal structures for the inverse purpose of granting freedoms that promote sharing and collaboration. They grant the recipient the rights to use the software, examine the source code, modify it, and distribute the modifications. These licenses target computer software where source code can be necessary to create modifications.
Open standardAn open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to their inherently open nature. There is no single definition, and interpretations vary with usage. The terms open and standard have a wide range of meanings associated with their usage.
Open accessOpen access (OA) is a set of principles and a range of practices through which research outputs are distributed online, free of access charges or other barriers. Under some models of open access publishing, barriers to copying or reuse are also reduced or removed by applying an open license for copyright. The main focus of the open access movement is "peer reviewed research literature". Historically, this has centered mainly on print-based academic journals.
Linear no-threshold modelThe linear no-threshold model (LNT) is a dose-response model used in radiation protection to estimate stochastic health effects such as radiation-induced cancer, genetic mutations and teratogenic effects on the human body due to exposure to ionizing radiation. The model statistically extrapolates effects of radiation from very high doses (where they are observable) into very low doses, where no biological effects may be observed.
Open-source softwareOpen-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative, public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite.
