omniomni/omni-engineering huggingface dataset:
Tefkat. Tefkat is a model transformation language and a model transformation engine.  The language is based on F-logic and the theory of stratified logic programs.  The engine is an Eclipse plug-in for the Eclipse Modeling Framework (EMF).

History 

Tefkat was one of the sub-projects of the Pegamento project at the Distributed Systems Technology Centre (DSTC), Australia.  Although the project was already underway, the most active research occurred for the submission of a response to the OMG's  MOF 2.0  Queries / Views / Transformations Request for Proposals.

Tefkat was open-sourced before the closure of the DSTC in June 2006.

Brief description 

Tefkat defines a mapping from a set of source metamodels to a set of target metamodels.  A Tefkat transformation consists of rules, patterns and templates.  Rules contain a source term and a target term.  Patterns are simply named composite source terms, and templates are simply named composite target terms.  These elements are based on F-logic and pure logic programming, however the absence of function symbols means a significant reduction in complexity.

Tefkat has two more significant language elements: trackings and injections.  Trackings allow arbitrary relationships to be preserved in a trace model.  Injections allow the identity of target objects to be specified in terms of a function symbol.  Thus injections are similar (but more powerful) to QVT's keys, which specify a target object's identity to be a function of its type and some of its properties.

The declarative semantics of a Tefkat transformation is the perfect model of traces and targets that satisfies all the rules.  A more imperative semantics of a Tefkat transformation is the iterated least fixed-point of the immediate consequence of each rule.  Due to stratification, these semantics are equivalent and unambiguous.  Tefkat does not use explicit rule-calling; all (non-abstract) rules fire independently from all others, however rules can be loosely coupled using trackings, injections, rule extension and/or rule superseding.

Concrete syntax 

Tefkat has an SQL-like concrete syntax designed to concisely convey the intent of each rule, pattern or template.

 RULE ClassToTable
 FORALL  Class c { name: n; }
 MAKE    Table t { name: n; }
 ;

Compliance 

The Tefkat language is defined in terms of (E)MOF 2.0, however the engine is implemented in terms of Ecore, the EMOF-like metametamodel at the centre of EMF.  The language is very similar to the Relations package of QVT, however it is not strictly compliant.

See also 

 Model Driven Architecture (MDA): OMG's vision of MDE
 QVT: the OMG's adopted QVT specification
 Stratification (mathematics)
 Logic programming

References 

 Tefkat project page
 Practical Declarative Model Transformation with Tefkat

Specification languages
PHP accelerator. A PHP accelerator is a PHP extension designed to improve the performance of software applications written in the PHP programming language.

Operation 
Most PHP accelerators work by caching the compiled opcode/bytecode of PHP representation of php files to avoid the overhead of parsing and compiling source code on each request (some or even most of which may never be executed). To further improve performance, the cached code is stored in shared memory and directly executed from there, minimizing the amount of slow disk reads and memory copying at runtime.

Practical benefits 
PHP accelerators substantially increase the speed of PHP applications.  Improvements of web page generation throughput by factors of two to seven have been observed.

The effect on application performance of opcode caching varies widely, depending on factors such as the inherent execution time of the PHP application and the percentage of source code actually executed on a given request, and whether additional optimization steps are performed. While a code optimizer may even slow down overall performance when used in isolation, it can provide an additional performance boost when coupled with a bytecode cache, as the optimization effort is performed just once.

See also 
 List of PHP accelerators

References

External links 
 Alternative PHP Cache , a widely used opcode cache.

Free proxy servers
PHP software
Me 262 Project. The Me 262 Project is a company formed to build flyable reproductions of the Messerschmitt Me 262, the world's first operational jet fighter. The project was started by the Texas Airplane Factory and administered by Classic Fighter Industries. It is based at Paine Field in Everett, Washington, United States, near Seattle. The project team of designers, engineers, and technicians completed the flight test program in 2012  and delivery of the first of five jets.

The aircraft are powered by General Electric CJ610 turbojet engines, concealed inside detailed reproductions of the original Junkers Jumo 004B engines and nacelles.

Production
Five aircraft were built:
 Me 262B-1c W.Nr.501241 reg.N262AZ
 Collings Foundation, Houston, Texas, US, in flying condition. First replica to fly, 20 December 2002.

 Me 262B-1c W.Nr.501242
 Evergreen Aviation Museum, McMinnville, Oregon, US, on static museum display. In the markings of an aircraft of Jadgeschwader 7 (11/JG-7) based at Brandenburg-Briest, flown by Leutnant Alfred Ambs.

 Me 262A/B-1c W.Nr.501243 reg.N262MF
 Military Aviation Museum, Virginia Beach, Virginia, US, in airworthy condition.

 Me 262A/B-1c W.Nr.501244 reg.D-IMTT
 Messerschmitt Stiftung, Manching, Germany, in airworthy condition.

References

Notes

Bibliography

External links
 Stormbird – Air & Space Magazine
 New Me-262 Reproduction Lands at the Museum – Evergreen Aviation & Space Museum
 Aviation History Book Review: Project 262 – HistoryNet
 Messerschmitt – aeRoman
 Group Building Messerschmitt Jets Near Seattle – East Oregonian

Aerospace companies of the United States
Multinational aircraft manufacturers
Everett, Washington
Messerschmitt Me 262
VTI. VTI may refer to:

 Virtual TI (Virtual Texas Instruments Calculator)
 The Vanguard Group Total Stock Market ETF, an exchange-traded fund with ticker symbol VTI
 Velocity time integral, a measurement in echocardiography
 Vermeer Technologies, original developer of Microsoft FrontPage
 Volda TI, Norwegian sports club
 VTI trademark by VLSI Technology
 Video Terminal Interface (VTI), a video display interface of the polymorphic Poly-88
 Virtual Tunnel Interface, another method for route-based IPsec; see VyOS
 VTI Engine ("Variable valve lift and Timing Injection"), engine developed by PSA Peugeot Citroën and BMW
 Swedish National Road and Transport Research Institute, a transport research institute in Sweden
Laboratório Nacional de Engenharia Civil. The Laboratório Nacional de Engenharia Civil, National Laboratory for Civil Engineering, (LNEC) is a public institution of scientific and technological research and development in Portugal and is a civil engineering laboratory.

LNEC operates in the different fields of civil engineering under the jurisdiction of the Ministry of Economy, in cooperation with the Ministry of Education and Science in the definition of its strategic guidelines, as established in its Organic Law, Decree Law 157/2012, of July 18.

History

LNEC was founded on November 19, 1946, from the Laboratory for Materials Testing and Study of the Ministry of Public Works and the Center for Civil Engineering Studies, based at the Instituto Superior Técnico. This double-strand, research and experimentation, would decisively shape the future development of LNEC.

On June 20, 1987, LNEC was made Honorary Member of the Military Order of Saint James of the Sword and on November 19, 1987, was made Honorary Member of the Military Order of Christ.

LNEC carries out research activities in the following fields: public works, housing, urban planning, environment, water resources, estuaries, coastal areas, transportation and communication networks, materials industry, building components and other products. The main purpose of these activities is to contribute to:
 the quality and safety of works;
 the protection and rehabilitation of the natural and built patrimony;
 the technological modernisation and innovation in the building sector;
 the minimisation of natural and technological hazards;
 the development of natural resources from a viewpoint of sustainable development.

Those activities are as follows:
 Planned research of a strategic nature, developed within research lines considered as priority due to their relevance for the country.
 Studies and expert reports under contract: advanced expert advisory services to public and private bodies, both national and foreign.
 Promotion of quality in construction: preparation of specifications, norms and regulations, approval and classification of new building materials and components, observation of the performance of works, certification of building projects by LNEC "Quality Mark" and normal tests.
 Dissemination of knowledge, as well as technical and scientific training: preparation of scientific and technical documents, organisation of technical courses or other training actions, organisation of scientific and technical meetings, both national and foreign, complemented by the publishing activity and by the Library.
 Cooperation with other bodies: activities of co-operation with various Portuguese and foreign bodies, namely with associations of a scientific and technical character, universities, laboratories and other institutions.

References

External links
 LNEC website

1946 establishments in Portugal
Research institutes in Portugal
Engineering research institutes
Research institutes established in 1946
ACF2. ACF2 (Access Control Facility 2) is a commercial, discretionary access control software security system developed for the MVS (z/OS today), VSE (z/VSE today) and VM (z/VM today) IBM mainframe operating systems by SKK, Inc. Barry Schrager, Eberhard Klemens, and Scott Krueger combined to develop ACF2 at London Life Insurance in London, Ontario in 1978.  The "2" was added to the ACF2 name by Cambridge Systems (who had the North American marketing rights for the product) to differentiate it from the prototype, which was developed by Schrager and Klemens at the University of Illinois—the prototype name was ACF. The "2" also helped to distinguish the product from IBM's ACF/VTAM.

ACF2 was developed in response to IBM's RACF product (developed in 1976), which was IBM's answer to the 1974 SHARE Security and Data Management project's requirement whitepaper.  ACF2's design was guided by these requirements, taking a resource-rule oriented approach.  Unique to ACF2 were the concepts of "Protection by Default" and resource pattern masking.

As a result of the competitive tension between RACF and ACF2,  IBM matured the SAF (Security Access Facility) interface in MVS (now z/OS), which allowed any security product to process operating system ("OS"), third-party software and application security calls, enabling the mainframe to secure all facets of mainframe operations.

SKK and ACF2 were sold to UCCEL Corporation in 1986, which in turn was purchased by Computer Associates International, Inc. in 1987.  Broadcom Inc. now (2019) markets ACF2 as CA ACF2.

References

Operating system security
Computer access control frameworks
CA Technologies
IBM mainframe software
Physica Scripta. Physica Scripta is an international scientific journal for experimental and theoretical physics. It was established in 1970 as the successor of Arkiv för Fysik and published by the Royal Swedish Academy of Sciences (KVA). Since 2006, it has been published by IOP Publishing with the endorsement of the KVA. The journal covers both experimental and theoretical physics, with an accent on atomic, molecular and optical physics, plasma physics, condensed matter physics and mathematical physics.

Abstracting, indexing, and impact factor
According to the Journal Citation Reports, the journal has a 2023 impact factor of 2.6.

It is indexed in the following bibliographic databases:
Chemical Abstracts
Science Citation Index Expanded
Compendex
GeoRef
Inspec
Scopus
Zentralblatt MATH

References

External links

Physics journals
IOP Publishing academic journals
Royal Swedish Academy of Sciences
Academic journals established in 1970
Tom Harris (mechanical engineer). Tom Harris (born 1953) is a Canadian mechanical engineer, executive director of the climate contrarian International Climate Science Coalition (ICSC)  and former executive director of the Natural Resources Stewardship Project. Harris has 30 years’ experience working as a mechanical engineer, project manager, and in science and technology communications.   From May to September 2006, he was Ottawa operations director of the High Park Group, a public relations and lobbying firm active in creating debate over global warming.

Work at the International Climate Science Coalition
The ICSC calls itself "a non-partisan group of independent scientists", but has been described as having "less to do with science than with public relations". Geochemist and National Science Board member James Lawrence Powell contrasts the mission and principles of the ICSC with those of the American Geophysical Union. In Powell's opinion, the ICSC is a "denier organization" that "know[s] the answers and seek[s] only confirmation that they are right. One group of minds is open; the other closed".

James Hoggan, public relations professional and Chair of the board of the David Suzuki Foundation, and Richard Littlemore of DeSmogBlog.com quoted and analyzed some paragraphs from the ICSC website. They noted that Harris's views as executive director of the ICSC were published from the same IP address as and shared the tactics of the climate change denial organizations New Zealand Climate Science Coalition and Australian Climate Science Coalition. The New Zealand Climate Science Coalition created the ICSC in 2007 and ICSC led the creation of the Australian Climate Science Coalition in 2008, and the Climate Science Coalition of America in 2010.

Speech at the 2008 International Conference on Climate Change
At the 2008 International Conference on Climate Change hosted by the Heartland Institute, Tom Harris gave a speech in which he discussed what he called "information sharing" and "coordinated local activism":

[...] We need regular high-impact media coverage of the findings of leading scientists — not just one or two publications, but we need to have hundreds all over the world. We need to have a high degree of information sharing and cooperation between groups, so that when Vincent Gray for example has an article published in New Zealand, we can take the same piece and we can (say) submit it to newspapers all over North America and Europe.

References

External links
International Climate Science Coalition, official website

Living people
Canadian mechanical engineers
Canadian lobbyists
1953 births
Engineers from Ontario
Scientists from Ottawa
USCGC Bear (WMEC-901). USCGC Bear (WMEC-901) is a United States Coast Guard medium endurance cutter. She was laid down August 23, 1979 and launched September 25, 1980 by the Tacoma Boatbuilding Company of Tacoma, Washington. She was commissioned February 4, 1983. She was named for  USRC Bear (AG-29), a steam barquentine that was built in Scotland and served the United States Treasury Department in the United States Revenue Cutter Service's Alaskan Patrol.

History 

In 1986, Bear responded to the Space Shuttle Challenger disaster by searching over 1900 square nautical miles (6,500 km²). During any given patrol, Bear conducts a wide-spectrum of missions such as search and rescue, alien migrant interdiction operations, counter-drug patrols, fisheries enforcement, and international engagement—illustrating the versatile, multi-mission character of the Coast Guard and the cutter fleet. Since her commissioning she has made 25 significant drug seizures involving 12 marijuana and 13 cocaine busts. According to the Office of Maritime Law Enforcement, in 2023, Bear set the record for most interdictions in one deployment in which the crew stopped 6 go-fasts, preventing 8,500 pounds of cocaine from reaching the U.S. and keeping $90M out of the hands of criminals.

In 1999, Bear was deployed with the USS Theodore Roosevelt (CVN-71) Battle Group to support NATO combat operations during Operation Allied Force. During this the Bear performed various mission such as surface surveillance, provided backup Search and Rescue response, combat escort for US Army transport vessels in areas where the cutter was well within range of enemy missiles, and provided force protection for the Amphibious Ready Group operating near Albania. Vice Admiral Murphy stated how well and how seamlessly Bear and her crew performed naval operations. This was due to the Bear's interoperability, crew training and knowledge in naval warfare and naval war fighting doctrine, and adequate weaponry. Bear was awarded the Kosovo Campaign Medal and the NATO Kosovo Medal. In 2023, Bears NR1 Main Diesel Engine clocked 100,000 hours, a testament to the dedication and skill of Coast Guard engineers. As of Spring 2024, Bear has deployed 74 times since launch.

Notes

External links
 
Bear home page

1980 ships
Famous-class cutters
Ships built by Tacoma Boatbuilding Company
Ships of the United States Coast Guard
Formatted File System. The Formatted File System (FFS) is the name of a series of Database Management Systems (DBMS) developed for military use and designed to run on IBM mainframe computers.

The period from 1964 to 1968 saw the transition from isolated DBMS development efforts to the development of DBMS families.  The Formatted File System is one such family. Others included General Electric's IDS family, and the Mark IV series developed by Informatics Inc. (later acquired by Sterling Software). These families were developed across organizations and branches of government, spreading and evolving with their primary developers.  Beginning around 1968, industry DBMS development became increasingly proprietary.

Family Members 

IRS(DTMB), 1958, IBM 704
Information Retrieval System (David Taylor Model Basin)
TUFF/TUG(DTMB), 1959, IBM 704/9
Tape Update for Formatted Files / Tape Updater and Generator (David Taylor Model Basin)
FFS(SAC), 1961, IBM 7090
Formatted File System (Strategic Air Command) 
FFS(IDHS), 1963, IBM 1401
Formatted File System (Intelligence Data-Handling System)
FFS(FICEUR), 1963, IBM 1410
Formatted File System (Naval Fleet Intelligence Center in Europe)
FFS(DIA-IDHS), 1965, IBM 1410
Formatted File System (Defense Intelligence Agency - Intelligence Data-Handling System)
GIS, 1965, IBM SYSTEM/360
Generalized Information System
NIPS, 1965, IBM 1410
NMCS (National Military Command System) Information Processing System
NIPS, 1968, IBM SYSTEM/360
NMCS (National Military Command System) Information Processing System
CDMS, 1968, IBM SYSTEM/360
Cobol Data Management System

References 

Proprietary database management systems
IBM mainframe software
Die (integrated circuit). A die, in the context of integrated circuits, is a small block of semiconducting material on which a given functional circuit is fabricated. Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon (EGS) or other semiconductor (such as GaAs) through processes such as photolithography. The wafer is cut (diced) into many pieces, each containing one copy of the circuit. Each of these pieces is called a die.

There are three commonly used plural forms: dice, dies, and die. To simplify handling and integration onto a printed circuit board, most dies are packaged in various forms.

Manufacturing process 

Most dies are composed of silicon and used for integrated circuits. The process begins with the production of monocrystalline silicon ingots. These ingots are then sliced into disks with a diameter of up to 300 mm.

These wafers are then polished to a mirror finish before going through photolithography. In many steps the transistors are manufactured and connected with metal interconnect layers. These prepared wafers then go through wafer testing to test their functionality. The wafers are then sliced and sorted to filter out the faulty dies. Functional dies are then packaged and the completed integrated circuit is ready to be shipped.

Uses 

A die can host many types of circuits. One common use case of an integrated circuit die is in the form of a central processing unit (CPU). Through advances in modern technology, the size of the transistor within the die has shrunk exponentially, following Moore's law. Other uses for dies can range from LED lighting to power semiconductor devices.

Images

Images of dies are commonly called die shots.

See also
 Die preparation
 Integrated circuit design
 Wire bonding and ball bonding

References

External links 
  – animation

Integrated circuits
1,4-Butynediol. 1,4-Butynediol is an organic compound that is an alkyne and a diol.  It is a colourless, hygroscopic solid that is soluble in water and polar organic solvents. It is a commercially significant compound in its own right and as a precursor to other products.

Synthesis
1,4-Butynediol can be produced in the Reppe synthesis, where formaldehyde and acetylene are the reactants:
2 CH2O  +  HC≡CH  →  HOCH2CCCH2OH

Several patented production methods use copper bismuth catalysts coated on an inert material. The normal temperature range for the reaction is 90 °C up to 150 °C, depending on the pressure used for the reaction which can range from 1 to 20 bar.

Applications 
1,4-Butynediol is a precursor to 1,4-butanediol and 2-butene-1,4-diol by hydrogenation.   It is also used in the manufacture of certain herbicides, textile additives, corrosion inhibitors, plasticizers, synthetic resins, and polyurethanes.  It is the major raw material used in the synthesis of vitamin B6.  It is also used for brightening, preserving, and inhibiting nickel plating.

It reacts with a mixture of chlorine and hydrochloric acid to give mucochloric acid, HO2CC(Cl)=C(Cl)CHO (see mucobromic acid).

Safety 
1,4-Butynediol is corrosive and irritates the skin, eyes, and respiratory tract.

See also
Acetylenedicarboxylic acid (but-2-ynedioic acid, 2-butynedioic acid)
cis-Butene-1,4-diol
2-Butyne (but-2-yne)

References 

Alkyne derivatives
Diols
Old Iron Bridge (Bastrop, Texas). The Old Iron Bridge, also referred to as Colorado River Bridge, is a -long bridge with three steel truss spans and concrete piers that crosses the Colorado River in Bastrop, Texas, United States. The bridge is one of the earliest surviving uses of the Parker truss in Texas.

History 
With automobiles becoming the dominant form of transportation in the United States after World War I, a new bridge was needed to handle the increasing traffic between Houston and Austin. The original estimate of the cost of the Old Iron Bridge was $45,000 and was partially financed by bonds and local taxes. Bids on the project were solicited and the Kansas City Bridge Co. was selected as contractor. The final cost of the bridge's construction was $167,500. The bridge was completed in 1923 and opened for use in January 1924. The original bridge torn down in the early 1930s.

The bridge was listed in the National Register of Historic Places on July 19, 1990.

See also

National Register of Historic Places listings in Bastrop County, Texas
List of bridges on the National Register of Historic Places in Texas
List of crossings of the Colorado River

References

External links

Buildings and structures in Bastrop County, Texas
Bridges completed in 1923
Road bridges on the National Register of Historic Places in Texas
National Register of Historic Places in Bastrop County, Texas
Transportation in Bastrop County, Texas
Former toll bridges in Texas
Bridges over the Colorado River (Texas)
Steel bridges in the United States
Parker truss bridges in the United States