omniomni/omni-engineering huggingface dataset:
Native (computing). In computing, native software or data-formats are those that were designed to run on a particular operating system. In a more technical sense, native code is code written specifically for a certain processor. In contrast, cross-platform software can be run on multiple operating systems and/or computer architectures.

For example, a Game Boy receives its software through a cartridge, which contains code that runs natively on the Game Boy. The only way to run this code on another processor is to use an emulator, which simulates an actual Game Boy. This usually comes at the cost of speed.

Applications 
Something running on a computer natively means that it is running without any external layer requiring fewer software layers. For example, in Microsoft Windows the Native API is an application programming interface specific for the Windows NT kernel, which can be used to give access to some kernel functions, which cannot be directly accessed through a more universal Windows API.

Operating systems 
Used to denote either the absence of virtualization or virtualization at its lowest level. When various levels of virtualization take place, the lowest level operating system—the one that actually maintains direct control of the hardware—is referred to as a "Native VM," for example.

Machine code 

Machine code, also known as native code, is a program which is written in machine language. Machine code is usually considered the lowest level of code for a computer, that, in its lowest level form, is written in binary (0s and 1s), but is often written in hexadecimal or octal to make it a little easier to handle. These instruction sets are then interpreted by the computer. With this, there is no need for translation. machine code is strictly numerical and usually isn't what programmers program in, due to this complex nature. Machine code is also as close as you can get to the processor, so using this language, you are programming specifically for that processor as machine code for each processor may differ. Typically programmers will code in high-level languages such as C, C++, Pascal, (or other directly compiled languages) which gets translated into assembly code, which then translates it into machine code (or in most cases the compiler generates machine code directly). Since each CPU is different, programs need to be recompiled or rewritten in order to work on that CPU.

Data 

Applied to data, native data formats or communication protocols are those supported by a certain computer hardware or software, with maximal consistency and minimal amount of additional components.

For example, EGA and VGA video adapters natively support code page 437. This does not preclude supporting other code pages, but it requires either a font uploading or using graphic modes.

Cloud computing 
In cloud computing, "cloud native" refers to the software approach of building, deploying, and managing modern applications in cloud computing environments, for software optimised for running on a cloud-based platform. A cloud native application typically consists of individual modular microservices.

References

Computer jargon
Orbital Sciences X-34. The Orbital Sciences X-34 was intended to be a low-cost testbed for demonstrating "key technologies" that could be integrated into the Reusable Launch Vehicle program. It was intended to be an autonomous pilotless craft powered by a "Fastrac" liquid-propellant rocket engine, capable of reaching Mach 8 and performing 25 test flights per year. 

The X-34 began as a program for a suborbital reusable-rocket technology demonstrator. In early 2001, the first flight vehicle was near completion, but the program was ended due to budget concerns. Up to this point, the project had encompassed spending of just under $112 million: $85.7M from the original contract with designer Orbital Sciences, $16M from NASA and various government agencies for testing, and an additional $10M for Orbital Sciences to adapt its L-1011 carrier aircraft to accommodate the X-34. The program was officially canceled by NASA on March 31, 2001. The unpowered prototype had been used only for towing and captive flight tests when the project was canceled.

The two demonstrators remained in storage at Edwards Air Force Base until they were temporarily moved to Mojave, California, in late 2010. This prompted some speculation that they might be restored to flight status. , the spaceplanes were lying in the yard of a crane company in nearby Lancaster, California.

Gallery

See also
 List of experimental aircraft
 Cygnus (spacecraft)
 Lockheed Martin X-33
 Prometheus (spacecraft) (CCdev)
 Sierra Nevada Dream Chaser (CCdev)

References

Further reading

External links
 
 NASA Dryden X-34 Technology Testbed Demonstrator Photo Collection
 Federation of American Scientists

Edwards Air Force Base
Spaceplanes
X-34, Orbital Sciences
Unflown aircraft
Boeing X-40. The Boeing X-40 Space Maneuver Vehicle is a test platform for the Boeing X-37 reusable spaceplane, built by Boeing Phantom Works. It sought to test the X-37's systems in order to "reduce the cost and risk of future reusable space launch vehicle system."

History
The uncrewed X-40A was a 80%-90% subscale version of the Boeing X-37 reusable spaceplane, but lacking in propulsion or thermal protection systems. Boeing built the X-40A originally for the Air Force as part of that service’s Space Maneuver Vehicle program.

The aircraft was built at Boeing Phantom Works at Seal Beach, California, in partnership with the Air Force Research Laboratory.

After the first drop test in August 1998 the vehicle was transferred to NASA, which modified it. Between April 4 and May 19, 2001, the vehicle successfully conducted seven free flights. In 2001 it successfully demonstrated the glide capabilities of the X-37's fat-bodied, short-winged design and validated the proposed guidance system.

Testing
The first X-40A drop test occurred at Holloman AFB, New Mexico on August 11, 1998 at 06:59. It was released from an altitude of approximately  and  away from the end of Runway 04 by a UH-60 Black Hawk helicopter (later tests used an Army CH-47D Chinook helicopter). The vehicle dove to the runway in an approach similar to the Space Shuttle's, flared, and landed left of the runway centerline. Its drag chutes successfully deployed, and the vehicle tracked to within  of the centerline and stopped at a distance of slightly more than .

The X-40A flew seven approach and landing test flights at NASA’s Dryden (now Armstrong) Flight Research Center in Edwards, California, in 2001 to reduce risk for the X-37 program, including in-flight evaluation of guidance, navigation and control software for its autonomous flight controls. One test flight the craft was towed by an Army CH-47D Chinook helicopter to an altitude of 15,000 feet, and then released to fly an autonomously controlled 75-second descent to a landing on the main runway at Edwards Air Force Base, where it then glided and guided itself.

Specifications (X-40A)

See also

References

External links

 NASA Dryden X-40A Image Gallery 
 X-40A Test Flight, Boeing press release
 X-40 Space Maneuver Vehicle Integrated Tech Testbed at FAS.org 
 Boeing X-37 / X-40 page at Designation-Systems.Net

X-40
Spaceplanes
X-40, Boeing
1990s United States military gliders
V-tail aircraft
Military space program of the United States
Air Force Research Laboratory projects
Low-wing aircraft
Aircraft with retractable tricycle landing gear
Glider aircraft
Concurrent user. In computer science, the number of concurrent users (sometimes abbreviated CCU) for a resource in a location, with the location being a computing network or a single computer, refers to the total number of people simultaneously accessing or using the resource. The resource can, for example, be a computer program, a file, or the computer as a whole.

Keeping track of concurrent users is important in several cases. First, some operating system models such as time-sharing operating systems allow several users to access a resource on the computer at the same time. As system performance may degrade due to the complexity of processing multiple jobs from multiple users at the same time, the capacity of such a system may be measured in terms of maximum concurrent users.

Second, commercial software vendors often license a software product by means of a concurrent users restriction. This allows a fixed number of users access to the product at a given time and contrasts with an unlimited user license. For example: Company X buys software and pays for 20 concurrent users. However, there are 100 logins created at implementation. Only 20 of those 100 can be in the system at the same time, this is known as floating licensing.

Concurrent user licensing allows firms to purchase computer systems and software at a lower cost because the maximum number of concurrent users expected to use the system or software at any given time (those users all logged in together) is only a portion of the total system users employed at a company. The concurrent licenses are global and shared by anyone who needs to use the system. This contrasts with "named-seats" licensing, in which one license must be purchased for each and every individual user, whether they are using the system or not.

If a company employs 400 system users in which 275 work during the day and 125 work at night, then they can opt to purchase only 275 concurrent user licenses since there will never be more than 275 users on the system during a normal work day. The night workers share 125 of the day users' licenses to use the system. For named-seat licenses, this same company would have to purchase 400 individual licenses, one for each user, and licenses would not be globally shared. The available options for licensing are entirely at the discretion of the vendor selling the product.

See also
Floating licensing

References

Computing terminology
OpenMosix. openMosix was a free cluster management system that provided single-system image (SSI) capabilities, e.g. automatic work distribution among nodes. It allowed program processes (not threads) to migrate to machines in the node's network that would be able to run that process faster (process migration). It was particularly useful for running parallel applications having low to moderate input/output (I/O). It was released as a Linux kernel patch, but was also available on specialized Live CDs. openMosix development has been halted by its developers, but the LinuxPMI project is continuing development of the former openMosix code.

History

openMosix was originally forked from MOSIX by Moshe Bar on February 10, 2002 when MOSIX became proprietary software.

openMosix was considered stable on Linux kernel 2.4.x for the x86 architecture, but porting to Linux 2.6 kernel remained in the alpha stage. Support for the 64-bit AMD64 architecture only started with the 2.6 version.

On July 15, 2007, Bar announced that the openMOSIX project would reach its end of life on March 1, 2008, due to the decreasing need for 
single system image (SSI) clustering as low-cost multi-core processors increase in availability.

OpenMosix used to be distributed as a Gentoo Linux kernel choice, but it was removed from Gentoo Linux's Portage tree in February 2007.

As of March 1, 2008, openMosix read-only source code is still hosted at SourceForge. The OpenPMIx project is continuing development of the former openMosix code.

ClusterKnoppix

ClusterKnoppix is a specialized Linux distribution based on the Knoppix distribution, but which uses the openMosix kernel.

Traditionally, clustered computing could only be achieved by setting up individual rsh keys, creating NFS shares, editing host files, setting static IPs, and applying kernel patches manually.  ClusterKnoppix effectively renders most of this work unnecessary.  The distribution contains an autoconfiguration system where new ClusterKnoppix-running computers attached to the network automatically join the cluster.

ClusterKnoppix is a modified Knoppix distro using the OpenMosix kernel.

See also

Kerrighed
OpenSSI

Live CDs
Linux Live CDs with openMosix include:
CHAOS (a very small boot CD)
dyne:bolic
Quantian, a scientific distribution based on clusterKnoppix

References

External links

openMosixWiki
 Original page at wayback archive
 ClusterKnoppix at sourceforge.net
  Clusterknoppix at distrowatch
 Load-Balancing cluster HowTo using ClusterKnoppix
 http://ftp.fi.muni.cz/pub/linux/clusterKnoppix/
 http://ftp.linux.cz/pub/linux/clusterKnoppix/
  OpenPMIx

openMosix cluster sites
Cluster at National Taras Shevchenko University of Kyiv
Hydra
MBG Cluster

Cluster computing
Internet Protocol based network software
Parallel computing
British Rail Class 09. The British Rail Class 09 is a class of 0-6-0 diesel locomotive designed primarily for shunting and short-distance freight trips along branch lines.

The 26 locos are nearly identical to the more numerous Class 08 shunting locomotives but have different gearing, giving a higher top speed of 27.5 mph (44 km/h) at the expense of a lower tractive effort. They were introduced from 1959 to 1962 and latterly operated in the Southern Region of British Railways, although some of the class were originally allocated to depots in the Midlands and North. Further locomotives were converted from Class 08 in 1992 and, following this and privatisation in 1997, the class has been distributed much further afield.

Passenger operations
Although not normally considered for passenger work, Class 09s were recorded working passenger trains between Clapham Junction and Kensington Olympia when the booked Class 33 diesel was unavailable.

They were also used on railtours which needed to depart Brighton heading along the West Coastway Line or vice versa. To achieve this the 09 worked between Brighton and Preston Park, allowing the main tour locomotive to work the train forward via the Cliftonville tunnel and Hove. The connection to the West Coastway Line at Brighton can only be used by four car trains due to the arrangement of the points and track.

Liveries

Post-Privatisation
The following liveries have been carried since the privatisation of British Rail:
 09006/007/019/024 carried Mainline Freight livery
 09008 in EWS livery
 09025 in Connex livery
 09204 in Arriva TrainCare livery
 09201 in Railfreight grey and is currently in the Knottingley area working at EWS Depot

Sub-classes

The original 26 locomotives (built 1959–1962) became sub-class 09/0 when further locomotives were modified from Class 08s in 1992 which became subclasses Classes 09/1 and 09/2.
There were variations, which were given the following TOPS design codes:

Class 09/0

Classes 09/1 & 09/2

Preservation
12 members of the class have been preserved

 09001 Ex DB Schenker at Peak Rail (Heritage Shunters Trust)
 D3668 (09004) at Swindon & Cricklade Railway
 D3721 (09010) at South Devon Railway
 D4100 (09012) Dick Hardy at Severn Valley Railway
 09015 at Avon Valley Railway 
 09017 at National Railway Museum
 09018 at Bluebell Railway
 09019 at West Somerset Railway
 09024 at East Lancashire Railway
 D4113 (09025) at Lavender Line
 09026 Cedric Wares at Spa Valley Railway
 09107 at Severn Valley Railway

Model railways
Lima produced a range of Class 09s in OO gauge.

Hornby Railways and Bachmann have also produced 00 gauge models of Class 09 locomotives.

References and sources

References

Sources

Further reading

External links 

 SEMG gallery

09
English Electric locomotives
C locomotives
Standard gauge locomotives of Great Britain
Railway locomotives introduced in 1959
Diesel–electric locomotives of Great Britain
Shunting locomotives
ISE. ISE may refer to:

Organizations
 International Society of Electrochemistry, a global scientific society founded in 1949
 Islamic Society of Engineers, principlist political organization of engineers in Iran

Education
 Iceland School of Energy, a school jointly owned by Reykjavik Energy, Reykjavik University, and Iceland GeoSurvey
 Institute for Shipboard Education, administrator of the Semester at Sea study-abroad program
 Institute for Social Ecology, an educational institution in Plainfield, Vermont
 International School Eindhoven, an international school in the northern part of Eindhoven, Netherlands
 International Student Exchange, Ontario, a non-profit organization allowing students to participate in reciprocal student exchange programs

Stock exchanges
 International Securities Exchange, a United States stock exchange
 Irish Stock Exchange, Ireland's main stock exchange
 Islamabad Stock Exchange, now Pakistan Stock Exchange
 Istanbul Stock Exchange, a former Turkish stock exchange that merged and became Borsa Istanbul

Other
 Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE), an institute of the Fraunhofer Society
 Information Sharing Environment, a United States government program
 Initiative for Science in Europe, an independent platform of European learned societies and scientific organisations
 ISE Corporation, a company that developed hybrid electric drivetrains for heavy-duty transportation
 Ion selective electrode, a transducer that converts the activity of a specific ion dissolved in a solution into an electrical potential
 Xilinx ISE, software for synthesis and analysis of hardware description language designs
 Integrated Scripting Environment (Windows PowerShell)

See also
 Ise (disambiguation)

de:Ise
Quasistatic process. In thermodynamics, a quasi-static process, also known as a quasi-equilibrium process (from Latin quasi, meaning ‘as if’), is a thermodynamic process that happens slowly enough for the system to remain in internal physical (but not necessarily chemical) thermodynamic equilibrium. An example of this is quasi-static expansion of a mixture of hydrogen and oxygen gas, where the volume of the system changes so slowly that the pressure remains uniform throughout the system at each instant of time during the process. Such an idealized process is a succession of physical equilibrium states, characterized by infinite slowness.

Only in a quasi-static thermodynamic process can we exactly define intensive quantities (such as pressure, temperature, specific volume, specific entropy) of the system at any instant during the whole process; otherwise, since no internal equilibrium is established, different parts of the system would have different values of these quantities, so a single value per quantity may not be sufficient to represent the whole system. In other words, when an equation for a change in a state function contains P or T, it implies a quasi-static process.

Relation to reversible process

While all reversible processes are quasi-static, most authors do not require a general quasi-static process to maintain equilibrium between system and surroundings and avoid dissipation, which are defining characteristics of a reversible process. For example, quasi-static compression of a system by a piston subject to friction is irreversible; although the system is always in internal thermal equilibrium, the friction ensures the generation of dissipative entropy, which goes against the definition of reversibility. Any engineer would remember to include friction when calculating the dissipative entropy generation. 

An example of a quasi-static process that is not idealizable as reversible is slow heat transfer between two bodies on two finitely different temperatures, where the heat transfer rate is controlled by a poorly conductive partition between the two bodies. In this case, no matter how slowly the process takes place, the state of the composite system consisting of the two bodies is far from equilibrium, since thermal equilibrium for this composite system requires that the two bodies be at the same temperature. Nevertheless, the entropy change for each body can be calculated using the Clausius equality for reversible heat transfer.

PV-work in various quasi-static processes

 Constant pressure: Isobaric processes, 
 Constant volume: Isochoric processes, 
 Constant temperature: Isothermal processes,  where  (pressure) varies with  (volume) via , so 
 Polytropic processes,

See also
 Entropy
 Reversible process (thermodynamics)

References

 Thermodynamic processes
 Statistical mechanics
Particle number. In thermodynamics, the particle number (symbol ) of a thermodynamic system is the number of constituent particles in that system. The particle number is a fundamental thermodynamic property which is conjugate to the chemical potential. Unlike most physical quantities, the particle number is a dimensionless quantity, specifically a countable quantity. It is an extensive property, as it is directly proportional to the size of the system under consideration and thus meaningful only for closed systems.

A constituent particle is one that cannot be broken into smaller pieces at the scale of energy  involved in the process (where  is the Boltzmann constant and  is the temperature). For example, in a thermodynamic system consisting of a piston containing water vapour, the particle number is the number of water molecules in the system. The meaning of constituent particles, and thereby of particle numbers, is thus temperature-dependent.

Determining the particle number
The concept of particle number plays a major role in theoretical considerations. In situations where the actual particle number of a given thermodynamical system needs to be determined, mainly in chemistry, it is not practically possible to measure it directly by counting the particles. If the material is homogeneous and has a known amount of substance n expressed in moles, the particle number N can be found by the relation :
,
where NA is the Avogadro constant.

Particle number density
A related intensive system parameter is the particle number density （or particle number concentration PNC), a quantity of kind volumetric number density obtained by dividing the particle number of a system by its volume. This parameter is often denoted by the lower-case letter n.

In quantum mechanics
In quantum mechanical processes, the total number of particles may not be preserved. The concept is therefore generalized to the particle number operator, that is, the observable that counts the number of constituent particles. In quantum field theory, the particle number operator (see Fock state) is conjugate to the phase of the classical wave (see coherent state).

In air quality
One measure of air pollution used in air quality standards is the atmospheric concentration of particulate matter. This measure is usually expressed in μg/m3 (micrograms per cubic metre). In the current EU emission norms for cars, vans, and trucks and in the upcoming EU emission norm for non-road mobile machinery, particle number measurements and limits are defined, commonly referred to as PN, with units [#/km] or [#/kWh]. In this case, PN expresses a quantity of particles per unit distance (or work).

References

Thermodynamics
Dimensionless numbers of thermodynamics
Countable quantities
State functions