omniomni/omni-engineering huggingface dataset:
Matita. Matita
is an experimental proof assistant under development at the Computer Science Department of the University of Bologna. It is a tool aiding the development of formal proofs by man–machine collaboration, providing a programming environment where formal specifications, executable algorithms and automatically verifiable correctness certificates naturally coexist.

Matita is based on a dependent type system known as the calculus of (co)inductive constructions (a derivative of the calculus of constructions), and is compatible, to some extent, with Coq.

The word "matita" means "pencil" in Italian (a simple and widespread editing tool). It is a reasonably small and simple application, whose architectural and software complexity is meant to be mastered by students, providing a tool particularly suited for testing innovative ideas and solutions. Matita adopts a tactic-based editing mode; (XML-encoded) proof objects are produced for storage and exchange.

Main features
Existential variables are native in Matita, allowing a simpler management of dependent goals.

Matita implements a bidirectional type inference algorithm exploiting both inferred and expected types.

The power of the type inference system (refiner) is further augmented by a mechanism of
hints
that helps in synthesizing unifiers in particular situations specified by the user.

Matita supports a sophisticated disambiguation strategy 
based on a dialog between the parser and the typechecker.

At the interactive level, the system implements a small step execution of structured tactics
allowing a much better management of the proof development, and naturally leading
to more structured and readable scripts.

Applications
Matita has been employed in CerCo (Certified Complexity): a 
FP7 European Project 
focused on the development of a formally verified, complexity preserving compiler from a large subset of C to the assembly language of a MCS-51 microprocessor.

Documentation
The Matita tutorial provides a pragmatic introduction to the main functionalities of the Matita interactive theorem prover, offering a guided tour through a set of non-trivial examples in the field of software specification and verification.

See also
Curry–Howard correspondence
Interactive theorem proving
Intuitionistic type theory
List of proof assistants

References

External links
  
 

Proof assistants
Free theorem provers
Dependently typed languages
Educational math software
OCaml software
Free software programmed in OCaml
Functional languages
VL Kotka. VL Kotka ("Eagle") was a Finnish two-seat, biplane maritime patrol aircraft, designed and built by the  or VL ("State Aircraft Factory"). It was meant as a cheaper replacement (compared to the Blackburn Ripon) for the outdated IVL A.22 Hansas that were in service with the Finnish Air Force.

The prototype made its first flight on September 30, 1930. In 1931, the State Aircraft Factory began production of a series of five aircraft. These were used as liaison aircraft until 1944.

One aircraft (KA-147) is on display at the Päijät-Häme Aviation Museum.

Versions
VL E.30 Kotka prototype KA-144 - this machine was built by the Finnish Government Aircraft Works, and was a prototype fitted with floats and a Bristol "Jupiter IV" engine.
VL E.30 Kotka I KA-145, 147 & 148 - three of the production aircraft (KA-145 – KA-148) fitted with regular landing gear (and could equip skis) and Wright R-1820-E Cyclone radial engines, 429 kW (575 hp).
VL E.30 Kotka I KA-146 - this machine was a Kotka I fitted with the same or very similar floats to the ones the KA-144 Kotka prototype had.
VL E.31 Kotka II KA-149 - the last, more modified series production aircraft fitted with a Pratt & Whitney R-1690-B Hornet engine, (575 hp).
VL E.32 Kotka III - cancelled third series due to the type being outdated.

Operators
 
 Finnish Air Force.

Specifications (KA-147, land aircraft)

See also

References

Citations

External links

1930s Finnish military aircraft
Transforming robots. A transforming robot is a robot that can change to take on the appearance or form of another object. This type of robot was a very popular toy concept in the 1980s; such toy robots could typically morph from a humanoid form to that of a vehicle, animal, or commonplace object. The transformation generally was by physically folding/bending/twisting and locking the robot's parts into the new shape, and it very rarely involved disassembling (physically separating) the parts and re-assembling them.

Toylines that used this concept include:
 Brave Reideen (Bandai and Popy)
 Transformers (Hasbro and Takara Tomy), a very popular franchise with two robot factions that fought against each other. The robots could transform into a wide range of things, like cars, trucks, planes, trains, motorcycles and robot animals.
 Gobots and Machine Robo (Tonka, Bandai), mostly die-cast toy robots that could transform into machines like cars, trucks, trains, boats and airplanes
 Rock Lords (Tonka, Bandai), robots that could transform into rocks
 NEO Shifters (Mattel, Mega Brands), robots that could transform into flying spheres
 Changeables (McDonald's), could transform into food products such as french fries or hamburgers.
 Escaflowne figures were incredibly popular in Japan in 2005.  They changed from a humanoid into a dragon.
 Switch & Go Dinos  (VTech), vehicles which transform into dinosaurs.
 Diarobo (ダイヤロボ) (Agatsuma Ltd), road vehicles changed into humans, animals and dinosaurs.
 The VF-1 Valkyrie or variable fighter from the popular Macross/Robotech franchise.
 Convertors (Select) featured the conflict between heroic and evil factions, in this case the heroic Defenders (and their Avarian allies) and the evil Maladroids (and their Insectors allies).

References

 
1980s toys
Super robot anime and manga
Argentium sterling silver. Argentium silver (patented in 1998) is a brand of modern tarnish-resistant silver alloys, containing either 93.5%, 94% or 96% silver. Argentium alloys replace some of the copper in the traditional sterling silver (92.5% silver + 7.5% copper) with the metalloid germanium.
Argentium 935, Argentium 940 and Argentium 960 alloys exceed the standard required for hallmarking as sterling silver, and Argentium 960 silver meets the standard for hallmarking as Britannia silver (95.84% silver).

Origins and description
Argentium silver is the result of research at the Art and Design Research Institute (ADRI), School of Art & Design, Middlesex University, by Peter Johns and colleagues. The project began in 1990 with research on the effects of germanium additions to silver alloys. Germanium was discovered to impart the following properties to sterling silver:
 firescale elimination
 high tarnish resistance
 precipitation hardening and simple heat-hardening properties
 increased ductility
 increased thermal and electrical resistance
 environmental advantages

Many of these properties significantly affect the traditional methods of working silver. For instance the absence of firescale eliminates tedious and time-consuming steps required by the silver worker using traditional sterling silver. It also eliminates the need for plating the final product which is often done on manufactured items because of the problems introduced by firescale. Tarnish resistance is of significant importance to both silver workers and the wearer of silver jewellery.

Argentium silver was patented and is trademarked by Argentium Silver Company, UK.

Physical properties

{| class="wikitable";
|+ 
!rowspan=2| Silveralloy
!colspan=2| Solidusmelting temperature 
!colspan=2| Liquidusflow point temperature 
|- style="text-align:center;"
| °C || °F || °C || °F
|- style="text-align:right;"
|   ||  802 °C || 1475 °F  ||  899 °C || 1650 °F
|-
|   ||  860 °C ||1580 °F ||895 °C ||1643 °F
|- style="text-align:right;"
|   ||  890 °C || 1634 °F   ||  920 °C || 1688 °F
|}

Footnotes

References

Further reading

External links
 
 

Silver
Precious metal alloys
Jewellery making
VL Sääski. VL Sääski II (English: mosquito) was the first series-produced aircraft designed in Finland. The aircraft was built by the State Aircraft Factory (Valtion lentokonetehdas) (abbreviated either V.L. or VL) and was a two-seat, biplane, single-engine trainer constructed out of wood.

Design and development
The aircraft was designed by Kurt Berger and Asser Järvinen in 1927 and the prototype  was financed by the ten-person construction team that built the aircraft in the A.E. Nyman workshop. The prototype was called Sääski I and was completed in the early spring of 1928. The aircraft's civil registration code was "K-SASA" and it was sold to the Finnish Air Force on June 25, 1928. The constructors of the aircraft formed a company called Sääski in 1928, obtained the manufacturing license from the designers, and had four improved Sääski II's built by the State Aircraft Company for civilian use. When a lack of orders threatened to drive the company to bankruptcy, the FAF ordered 10 Sääski II aircraft. These were built in 1930.

Two further series were ordered by the air force and the total production of the aircraft numbered 32 aircraft between 1930 and 1932. The second series (beginning with SÄ-127) differed from the first in having a greater span. This version was called Sääski IIA. The aircraft was considered to be safe and reliable and was also equipped with floats. The seaplane version was still able to do aerobatics.

One civilian aircraft was sold to Gidsken Jakobsen, a pioneering Norwegian aviator, in 1929, 19,000 Norwegian krone. She named it Måsen ("gull"). One Sääski II (SÄ-120) was modified with a new airfoil and ailerons in August 1935 and was given the nomenclature of Sääski IV.

Use in Finland
The Finnish Air Force operated 33 Sääski aircraft between 1928-1943: the 32 production aircraft bore the identification codes SÄ-113, SÄ-117 - SÄ-126 (version II), and SÄ-127 - SÄ-148 (version IIA), while the prototype, formerly known under the civil registration code K-SASA, was given the identification code SÄ-95 (version I). There were a further five Sääski in the civilian register. The aircraft was primarily used as a trainer but also for aerial photography, aerial gunnery practice, and as a liaison aircraft for the army. All Sääskis were removed from FAF inventory in January 1943.

One Sääski IIA is preserved today and is on display at the Finnish Aviation Museum in Vantaa. Another one, the former coast guard aircraft LK 1, is on display at Maritime Centre Vellamo in Kotka, Finland. The Norwegian Aviation Musemum houses a replica of Jakobsen's aircraft in Bodø, Norway.

Operators

 Finnish Air Force
 Finnish Border Guard

 Gidsken Jakobsen

Specifications (VL Sääski)

See also

References

1940s Finnish military aircraft
Core Component Technical Specification. A cornerstone of the UN/CEFACT standardisation activities is the Core Component Technical Specification (CCTS). Core Components are the syntax-neutral and technology-independent building blocks that can be used for data modeling. Major benefits of CCTS include improved reuse of existing data artifacts, improved enterprise interoperability, and consistency across vertical industry standards.

Related work includes the OASIS CAM specification and OASIS Registry Repository specification.

See also 
 OASIS
 OASIS Business Document Naming and Design Rules Version 1.0 (CCTS 2.01 and XML)
 OASIS Business Document Naming and Design Rules Version 1.1 (CCTS 2.01, XML and JSON)

External links
 UN/CEFACT
 UN/CEFACT: Core Components Technical Specification Version 2.01
 UN/CEFACT: Core Components Technical Specification Version 3.0
 UN/CEFACT: XML For CCTS Version 1.0

Tools 
 Crane Softwrights Ltd.'s ods2obdgc and gc2obdndr are used by the OASIS UBL committee to create XML document schemas from a spreadsheet expression of business objects described using the UN/CEFACT Core Component Technical Specification 2.01 using the OASIS Business Document Naming and Design Rules
 OASIS CAM Editor - create and compare libraries of core components from business exchanges

References 

United Nations Economic and Social Council
Tokamak (software). The Tokamak Game Physics SDK is an open-source physics engine.

At its beginnings, Tokamak was free for non commercial uses only. Since May 2007, it has become open sourced under a BSD License. Now it can be used under BSD or Zlib license, in order to make the source code exchange with other physics engine possible.

Features 

Tokamak features a unique iterative method for solving constraints.  This is claimed to allow developers to make trade-offs between accuracy and speed and provides more predictable processor and memory usage.  Tokamak's constraint solver does not
involve solving large matrices, thereby avoiding memory bandwidth limitations on some game consoles.

The SDK supports a variety of joint types and joint limits and a realistic friction model.  Tokamak is optimized for stacking large numbers of objects - a frequently requested feature by game developers. Tokamak provides collision detection for primitives (box, sphere, capsule), combinations of primitives, and arbitrary static triangle meshes. Lightweight 'rigid particles' provide particle effects in games at minimal cost.

Tokamak also supports "Breakage Constructing models" which will break when a collision occurs. Fragments of the original model will automatically be spawned by Tokamak's built-in breakage functionality.

 collision detection✔
 Particle system?
 Rigid body dynamics?

See also 

 Physics Abstraction Layer

External links
Tokamak web site 
Tokamak sourceforge project page

Computer physics engines
Software using the BSD license
Software using the zlib license
System-specific impulse. System-specific Impulse, Issp is a measure that describes performance of jet propulsion systems.  A reference number is introduced, which defines the total impulse, Itot, delivered by the system, divided by the system mass, mPS:

Issp=Itot/mPS
Because of the resulting dimension, - delivered impulse per kilogram of system mass mPS, this number is called ‘System-specific Impulse’. In SI units, impulse is measured in newton-seconds (N·s) and Issp in N·s/kg.

The Issp allows a more accurate determination of the propulsive performance of jet propulsion systems than the commonly used Specific Impulse, Isp, which only takes into account the propellant and the thrust engine performance characteristics. Therefore, the Issp permits an objective and comparative performance evaluation of systems of different designs and with different propellants.

The Issp can be derived directly from actual jet propulsion systems by determining the total impulse delivered by the mass of contained propellant, divided by the known total (wet) mass of the propulsion system. This allows a quantitative comparison of for example, built systems.

In addition, the Issp can be derived analytically, for example for spacecraft propulsion systems, in order to facilitate a preliminary selection of systems (chemical, electrical) for spacecraft missions of given impulse and velocity-increment requirements.  A more detailed presentation of derived mathematical formulas for Issp and their applications for spacecraft propulsion are given in the cited references. In 2019 Koppel and others used ISSP as a criterion in selection of electric thrusters.

See also
Specific Impulse

References

Spacecraft propulsion
Physical quantities
Classical mechanics
Choo Byung-jik. Choo Byung-jik () was a South Korean politician. He was the 13th Minister for Construction.

Kazakh construction agreement
Minister Byung-jik announced on 25 September 2006 that the governments of South Korea and Kazakhstan, represented by Byung-jik and his Kazakh counterpart, agreed to increase cooperation in construction by having South Korean construction companies build roads, railways, airports and ports. According to a statement released by the South Korean Ministry, the Nazarbayev administration plans to build 4,000 kilometers of railways and 8,000 km of highways by 2015 to expand transportation infrastructure for the Caspian Sea field.

South Korea-Libya relations
The fourth session of the Libya-Korea mixed cooperation commission, co-chaired by Byung-jik and Ali Zikri, Secretary of the Libyan People's General Committee for communications and transport, was held on 21 September 2006. According to Angola Press, "Zikri promoted joint investments, transfer of technology, increase in trade and training, human resources development, tourism, health and energy." Zikri hinted that the Government of Libya wanted Korean investment in transportation and sanitation infrastructure development. Byung-jik expressed the South Korean government's willingness to increase investment in development projects, and cited the creation of an artificial river as evidence of past cooperation between the two nations. The ministers agreed to establish an economic, investment and tourism commission, and a construction, energy, training, transport, oil and electricity commission, to decide how cooperation, specifically South Korean investment, would benefit Libya and South Korea. Byung-jik accompanied South Korean Prime Minister Han Myeong Sook and the vice-ministers of foreign affairs, industry, information and communications, when they arrived in Tripoli on 20 September for an official visit. Libyan Prime Minister Baghdadi Mahmoudi hosted a dinner for the South Korean delegation.

References

Living people
Government ministers of South Korea
Kyungpook National University alumni
Jeonju Chu clan
1949 births
Oberlin Smith. Oberlin Smith (March 22, 1840 – July 19, 1926) was an American engineer who published one of the earliest works dealing with magnetic recording in 1888.

Biography
He was born on March 22, 1840, in Cincinnati, Ohio, to George R. and Salome (Kemp) Smith.

He started a small machine shop in Bridgeton, New Jersey, where he lived most of his life, which became known as the Ferracute Machine Company in 1877. For the entire existence of the company he was the president and chief engineer.

He died on July 19, 1926, in New Jersey.

Magnetic recording
On September 8, 1888, Smith published a short note entitled "Some Possible Forms of the Phonograph" in the British journal Electrical World, where he suggested (probably for the first time) the use of permanent magnetic impressions for the recording of sound. Smith suggested using cotton or silk thread, into which steel dust or short clippings of fine wire could be suspended. These particles were to be magnetized in accordance with the alternating current from a microphone source. Smith also discussed the possibility of using a hard metal wire or chain, but preferred the thread.

Smith built a machine to spin steel dust into thread, but could not harden the dust because of oxidation. As implementing his ideas would require thousands of hours of work, he published his theories but no one attempted to implement them. Many of Smith's ideas were independently reproduced by Valdemar Poulsen when he developed the first true magnetic recorder.

References

External links 
 Recognition at the NJ Inventor's Hall of Fame.
 Write up in local newspaper.
 Compilation  of Oberlin Smith biographical and technical information of his inventions.

1840 births
1926 deaths
American engineers
People from Bridgeton, New Jersey
Engineers from New Jersey
Anthony R. Michaelis. Anthony R. Michaelis (22 August 1916 – 18 October 2007) was a science journalist and publisher.

He was born Kurt Otto Adolf Michaelis, a doctor's son, in Berlin on August 22, 1916, and educated at the Falk Real Gymnasium. Although baptised a Lutheran, he had three Jewish grandparents, which meant that after Hitler came to power in 1933 he would not be allowed to study science - so his father sent him to London.

Michaelis studied aeronautical engineering at the Imperial College of the University of London before switching to Chemistry. He went on to obtain a doctorate on "The Dehydrogenation of Alicyclic Compounds and Terpenic Ketones in the Liquid Phase", while lecturing at Sheffield University under Sir Patrick Linstead.  He was interned as an 'enemy alien' in England in May 1940 and then Canada, where he formed lasting friendships with Klaus Fuchs, Max Perutz, Hermann Bondi and Tommy Gold. After he returned to Britain in December 1940, he joined the Auxiliary Fire Service whilst working as a chemist in a paint factory. After graduation, he became chief chemist at Milton Antiseptic.

After World War II Michaelis worked for the British Intelligence Objectives Committee, which investigated enemy scientific developments, and in 1946 he married Ann Aikman, with whom he was to have three children. His distinguished career as a science journalist and editor spanned several activities including the “BIOS project”, technical writing  at “CIBA” and “International Telecommunication Union” in Switzerland.  Later he became a scientific film author in Australia, editor of the British  magazine Discovery, science correspondent for   The Daily Telegraph where he wrote daily reports on science and technology from 1969 to 1973. He was also the founding editor and publisher of  Interdisciplinary Science Reviews.

Whilst at the Daily Telegraph, in 1968, Michaelis was the first person to coin and use the term "Pulsar" to describe the discovery of Jocelyn Bell Burnell and Antony Hewish of the "Pulsating Radio star" in 1967.

Michaelis became known as an expert on the subject of scientific cinematography. From 1950 to 1954 he worked at the University of Sydney and during this time wrote much of the textbook Research Films (1956, US). The National Library of Australia holds material related to the publication of this book.

He died in Heidelberg in 2007.

Books
 Overall Reports (editor), 1947
 Research Films, 1956
 Discovery (editor), 1955
 From Semaphore to Satellite, 1960
 The Scientific Temper, 2001

References

External links
 The Scientific Temper

1916 births
2007 deaths
German male journalists
German journalists
German male writers
Jewish German writers
Alumni of Imperial College London
Recipients of the Cross of the Order of Merit of the Federal Republic of Germany
20th-century German journalists
German expatriates in the United Kingdom
German expatriates in Australia