omniomni/omni-engineering huggingface dataset:
Reconnaissance aircraft. A reconnaissance aircraft (colloquially, a spy plane) is a  military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as well as measurement and signature intelligence. Modern technology has also enabled some aircraft and UAVs to carry out real-time surveillance in addition to general intelligence gathering.

Before the development of devices such as radar, military forces relied on reconnaissance aircraft for visual observation and scouting of enemy movement.  An example is the PBY Catalina maritime patrol flying boat used by the Allies in World War II:  a flight of U.S. Navy Catalinas spotted part of the Japanese fleet approaching Midway Island, beginning the Battle of Midway.

History

Prior to the 20th century, machines for powered and controllable flight were not available to military forces, but some attempts were made to use lighter than air craft. During the Napoleonic Wars and Franco-Prussian War, balloons were used for aerial reconnaissance by the French.

In World War I, aircraft were deployed during early phases of battle in reconnaissance roles as 'eyes of the army' to aid ground forces. Aerial reconnaissance from this time through 1945 was mostly carried out by adapted versions of standard fighters and bombers equipped with film cameras.  Photography became the primary and best-known method of intelligence collection for reconnaissance aircraft by the end of World War II.

World War I also saw use of floatplanes to locate enemy warships. After the battle of Jutland demonstrated the limitations of seaplane tenders, provisions were made for capital ships to carry, launch, and recover observation seaplanes.  These seaplanes could scout for enemy warships beyond the visual range of the ship's lookouts, and could spot the fall of shot during long range artillery engagements. Observation seaplanes were replaced by helicopters after World War II.

After World War II and during the Cold War the United States developed several dedicated reconnaissance aircraft designs, including the U-2 and SR-71, to monitor the nuclear arsenal of the Soviet Union.  Other types of reconnaissance aircraft were built for specialized roles in signals intelligence and electronic monitoring, such as the RB-47, RB-57, Boeing RC-135 and the Ryan Model 147 drones.

Since the Cold War much of the strategic reconnaissance aircraft role has passed over to satellites, and the tactical role to unmanned aerial vehicles (UAVs). This has been proven in successful uses by the United States in Desert Storm operations.

See also

 Aerial reconnaissance
 Surveillance aircraft
 List of United States Air Force reconnaissance aircraft
 Maritime patrol aircraft
 Observation seaplane

References

External links

spyflight
"A Tale of Two Airplanes" by Kingdon R. "King" Hawes, Lt Col, USAF (Ret.)

Army-Lockheed YO-3A "Quiet Star" - Official History
SableCC. SableCC is an open-source compiler generator (or interpreter generator) in Java. Stable version is licensed under the GNU Lesser General Public License (LGPL). Rewritten version 4 is licensed under Apache License 2.0.

SableCC includes the following features:
Deterministic finite automaton (DFA)-based lexers with full Unicode support and lexical states.
Extended Backus–Naur form grammar syntax. (Supports the *, ? and + operators).
LALR(1) based parsers.
Automatic generation of strictly-typed abstract syntax trees.
Automatic generation of tree-walker classes.

See also

ANTLR
JavaCC
Coco/R

References

External links
SableCC website

Parser generators
Java development tools
PVA. PVA may refer to:

Science and technology
 Paraventricular nucleus of hypothalamus, a part of the brain 
 Patterned vertical alignment, a thin-film-transistor liquid-crystal display technology
 Poikiloderma vasculare atrophicans, a skin disease
 Polyvinyl acetate, an adhesive used for porous materials like wood, paper, and cloth
 Polyvinyl alcohol, a water-soluble synthetic polymer
 Population viability analysis, a risk-assessment method used in conservation biology
 Positive vorticity advection in meteorology
 Potato virus A, an agricultural disease

Other uses
 Paralyzed Veterans of America, a veterans' service organization
 Kinder High School for the Performing and Visual Arts, in Houston, Texas, U.S.
 Perkiomen Valley Academy, in Pennsylvania, U.S.
 People's Volunteer Army, the Chinese armed forces active during the Korean War
 El Embrujo Airport, in Providencia Island, Colombia, IATA code PVA
 PVA (band), English music band

See also
WTP. WTP may refer to:

Arts and entertainment
 "WTP", a song from the album K.T.S.E. by American artist Teyana Taylor
 "W.T.P." ("White Trash Party"), a song by rapper Eminem; See the album Recovery
 Winnie-the-Pooh, a fictionalized bear in books by A. A. Milne

Philosophy
 Will to power, a prominent concept in the philosophy of Friedrich Nietzsche.

Science and technology
 Water treatment plant, a facility that performs water purification
 Web Tools Platform, a platform for the Eclipse software
 Western Treatment Plant, a sewage treatment plant in Australia
 Wireless transaction protocol, technical term in wireless communication

Other uses
 Besix Watpac, an Australian construction company ASX ticker code
 Willingness to pay, economic term used in pricing theory
 Women's Torah Project, transcription of the Torah entirely by women
 Warszawski Transport Publiczny, Warsaw's Public Transport Authority
 "We the People" is the opening phrase of the Preamble to the United States Constitution
ISWIM. ISWIM (If You See What I Mean) is an abstract computer programming language (or a family of languages) devised by Peter Landin and first described in his article "The Next 700 Programming Languages", published in the Communications of the ACM in 1966.

Although not implemented, it has proved very influential in the development of programming languages, especially functional programming languages such as SASL, Miranda, ML, Haskell and their successors, and dataflow programming languages like Lucid.

Design 
ISWIM is an imperative programming language with a functional core, consisting of a syntactic sugaring of lambda calculus to which are added mutable variables and assignment and a powerful control mechanism: the program point operator. Being based on lambda calculus, ISWIM has higher-order functions and lexically scoped variables.

The operational semantics of ISWIM are defined using Landin's SECD machine and use call-by-value, that is eager evaluation. A goal of ISWIM was to look more like mathematical notation, so Landin abandoned ALGOL's semicolons between statements and begin ... end blocks and replaced them with the off-side rule and scoping based on indentation.

A notationally distinctive feature of ISWIM is its use of where clauses. An ISWIM program is a single expression qualified by where clauses (auxiliary definitions including equations among variables), conditional expressions and function definitions. Along with CPL, ISWIM was one of the first programming languages to use where clauses.

A notable semantic feature was the ability to define new data types, as a (possibly recursive) sum of products. This was done using a somewhat verbose natural language style description, but apart from notation amounts exactly to the algebraic data types found in modern functional languages. ISWIM variables did not have explicit type declarations and it seems likely (although not explicitly stated in the 1966 paper) that Landin intended the language to be dynamically typed, like LISP and unlike ALGOL; but it is also possible that he intended to develop some form of type inference.

Implementations and derivatives 
No direct implementation of ISWIM was completed but Art Evan's language PAL, and John C. Reynolds' language Gedanken, captured most of Landin's concepts, including powerful transfer-of-control operations. Both of these were typed dynamically. Robin Milner's ML may be considered equivalent to ISWIM without the J operator and with type inference.

Another line of descent from ISWIM is to strip out the imperative features (assignment and the J operator) leaving a purely functional language. It then becomes possible to switch to lazy evaluation. This path led to programming languages SASL, Kent Recursive Calculator (KRC), Hope, Miranda, Haskell, and Clean.

References 

Programming languages created in 1966
Academic programming languages
Experimental programming languages
Functional languages
History of computing in the United Kingdom
Ballard Power Systems. Ballard Power Systems Inc. is a developer and manufacturer of proton exchange membrane (PEM) fuel cell products for markets such as heavy-duty motive (consisting of bus and tram applications), portable power, material handling as well as engineering services. Ballard has designed and shipped over 400 MW of fuel cell products to date.

History
Ballard was founded in 1979 by geophysicist Geoffrey Ballard, Keith Prater, and Paul Howard, under the name Ballard Research Inc. to conduct research and development on high-energy lithium batteries. Since committing to the development of PEM fuel cell technology in 1989, Ballard has delivered PEM fuel cell products worldwide to a number of leading product manufacturers.

Ballard went public in 1993 on the Toronto Stock Exchange (TSE), and in 1995 was listed on the NASDAQ. Ballard Power Systems opened a fuel cell manufacturing facility in 2000 in Burnaby, B.C.

Automotive fuel cell cooperations
On February 1, 2008, Ballard spun out Automotive Fuel Cell Cooperation (AFCC) to allow for further expansion of fuel cell technology. After the split, Ballard continued as a publicly traded company focusing on non-automotive applications (including buses), while AFCC became a privately held company of 150 employees, developing hydrogen fuel cell stacks for automobiles. AFCC's initial ownership split was Daimler AG (50.1%), Ford Motor Company (30.0%), and Ballard itself (19.9%).

In 2018, Ballard signed a contract with Weichai Power for a strategic partnership. Weichai acquired for US$163 million19.9 percent of Ballard's shares. As part of this collaboration, Ballard and Weichai intend to supply the Chinese market with fuel cell systems for trucks, busses, and forklifts.

In cooperation with German car manufacturer Audi, Ballard is part of a development partnership for automotive fuel cells, which will run at least until 2022. Ballard delivers fuel cells to bus manufacturers, e.g. Van Hool (Belgium), New Flyer (Canada) and Solaris (Poland).

Other activity areas
Besides road vehicles, Ballard delivers fuel cells also for trains, mining trucks, marine applications, and backup power systems for critical infrastructures such as radio towers. Furthermore, a fuel cell system for application in drones is under development.

Achievements
Ballard has:
 supplied vehicles with fuel cells traveling more than 200 million kilometers in total to date 2024 
 access to 2,000 patents/applications

References
https://www.bctechnology.com/news/2021/3/22/Fuel-Cell-Electric-Vehicles-Powered-by-Ballard-Have-Now-Driven-Over-75-Million-Kilometers--Enough-to-Circle-the-Globe-1870-Times.cfm

Companies listed on the Toronto Stock Exchange
Companies based in Burnaby
Fuel cell manufacturers
Pinking shears. Pinking shears are scissors with saw-toothed blades instead of straight blades. They produce a zigzag pattern instead of a straight edge. 

Before pinking scissors were invented, a pinking punch or pinking iron was used to punch out a decorative hem on a garment. The punch would be hammered by a mallet against a hard surface and the punch would cut through the fabric. In 1874, Eliza P. Welch patented an improved design for a pinking iron, which featured a pair of handles.

The pinking shears design that is most well known was patented by Louise Austin in 1893. In 1934, Samuel Briskman patented a pinking shear design (Felix Wyner and Edward Schulz are listed as the inventors). In 1952, Benjamin Luscalzo was granted a patent for pinking shears that would keep the blades aligned to prevent wear. 

Pinking shears are used for cutting woven cloth. Cloth edges that are unfinished will easily fray, the weave becoming undone and threads pulling out easily. The sawtooth pattern does not prevent the fraying but limits the length of the frayed thread and thus minimizes damage.

These scissors can also be used for decorative cuts and a number of patterns (arches, sawtooth of different aspect ratios, or asymmetric teeth) are available.

Etymology 

The cut produced by pinking shears may have been derived from the garden plant called the pink, in the genus Dianthus (the carnations). The color pink also may have been named after these flowers, although the origins of the name are not definitively known. As the pink has scalloped, or "pinked", edges to its petals, pinking shears can be thought to produce an edge similar to the flower. 

The verb "pink" dates back to 1300 meaning "pierce, stab, make holes in".

References

Scissors
Sewing equipment
Cryoelectronics. In electronics, cryoelectronics or cryolectronics is the study of superconductivity under cryogenic conditions and its applications. It is also described as the operation of power electronic devices at cryogenic temperatures. Practical applications of this field is quite broad, although it is particularly useful in areas where cryogenic environment exists such as superconducting technologies and spacecraft design. It also became a special branch of cryophysics and cryotechnics and plays a role in operations that require high resolution and precision measurements.

Cryoelectronic devices include the SQUIDs or the superconducting quantum interference devices, which represent magnetic sensors of highest sensitivity. They serve as the backbone of applications that range from materials evaluation, geological and environmental prospecting, and medical diagnostics, among others.

Marketable Uses 
A key factor in production of new technologies is whether it is cost effective and useful. Devices that make use of cryoelectronics and the applications of superconductivity such as computers, information transmission lines, and magnetocardiography have potential for commercial value outside of a few specific devices for singular purposes. At the same time, the presence of other devices made with highly specialized functions can be competitively marketed without having to rely on a large market.
 Devices and activities that are derived from this and have marketable functions include:
 Magnetometry: this includes magnetocardiography, communications, geomagnetism, and submarine detection. This includes several more specialized functions and some broader functions that can be derived from cryoelectronics.
 Computers: being able to mass-produce cheap, compact tunneling cryotron provides a diverse base of uses and marketing. 
 Electrical Metrology: Allowing for more precise readings and measurements of current, voltage, power, and attenuation ratio, this will allow for more precise control over maintaining legal levels which provides a specific need and use for the technology.
 Galvanometers: a range of measurement devices that will be of use to the scientific field though more precise measurements in specialized fields.

References

Superconductivity
Pontifex (project). PONTIFEX (Planning Of Non-specific Transportation by an Intelligent Fleet EXpert) was a mid-1980s project that introduced a novel approach to complex aircraft fleet scheduling, partially funded by the European Commission's Strategic Programme for R&D in Information Technology.

Since the mathematical problems stemming from nontrivial fleet scheduling easily become computationally unsolvable, the PONTIFEX idea consisted in a seamless merge of algorithms and heuristic knowledge embedded in rules. The system, based on domain knowledge collected from airliners Alitalia, KLM, Swissair, and TAP Portugal, was first adopted by Swissair and Alitalia in the late 1980s, then also by the Italian railroad national operator, for their cargo division. It was still in use .

References

Mathematical modeling
External combustion engine. An external combustion engine (EC engine) is a reciprocating heat engine where a working fluid, contained internally, is heated by combustion in an external source, through the engine wall or a heat exchanger. The fluid then, by expanding and acting on the mechanism of the engine, produces motion and usable work. The fluid is then dumped (open cycle), or cooled, compressed and reused (closed cycle). 
In these types of engines, the combustion is primarily used as a heat source, and the engine can work equally well with other types of heat sources.

Combustion
"Combustion" refers to burning fuel with an oxidizer, to supply the heat. Engines of similar (or even identical) configuration and operation may use a supply of heat from other sources such as nuclear, solar, geothermal or exothermic reactions not involving combustion; they are not then strictly classed as external combustion engines, but as external thermal engines.

Working fluid
The working fluid can be of any composition and the system may be single-phase (liquid only or gas only) or dual-phase (liquid/gas).

Single phase
Gas is used in a Stirling engine. Single-phase liquid may sometimes be used.

Dual phase
Dual-phase external combustion engines use a phase transition to convert temperature to usable work, for example from liquid to (generally much larger) gas.  This type of engine follows variants of the Rankine cycle.  Steam engines are a common example of dual-phase engines.  Another example is engines that use the Organic Rankine cycle.

See also

Organic Rankine cycle
Steam engines
Stirling engines
Trochilic engine
Internal combustion engine (ICE)
Nuclear power
Solar thermal rocket (an externally heated rocket)
Naptha engine, a variant of the steam engine, using a petroleum liquid as both fuel and working fluid.

References

Engines
Threading. Threading may refer to:

 Thread (computing), a programming technique
 Threading (epilation), a hair removal method
 Threading (manufacturing), the process of making a screw thread
 Threading (protein sequence), a method for computational protein structure prediction
 Threaded code, another programming technique
 Threaded discussion (conversation threading), a conceptual model, and its instantiations, in digital communication, including IMs, DMs, email, Usenet, commenting utilities, web forums, and so on
Assertion. Assertion or assert may refer to:

Computing
 Assertion (software development), a computer programming technique
 assert.h, a header file in the standard library of the C programming language
 Assertion definition language, a specification language providing a formal grammar to specify behaviour and interfaces for computer software

Logic and language
 Logical assertion, a statement that asserts that a certain premise is true
 Proof by assertion, an informal fallacy in which a proposition is repeatedly restated
 Time of assertion, in linguistics a secondary temporal reference in establishing tense
 Assertive, a speech act that commits a speaker to the truth of the expressed proposition

Other uses
 Assert (horse) (1979–1995), an Irish racehorse
 Assertions (auditing), the set of information that the statement preparer is providing in a financial statement audit

See also
Constructor. Constructor may refer to:

Science and technology
 Constructor (object-oriented programming), object-organizing method 
 Constructors (Formula One), person or group who builds the chassis of a car in auto racing, especially Formula One
 Constructor, an entity in Constructor theory, a theory of everything developed by physicist David Deutsch in 2012

Other uses
 Constructor (video game), a 1997 PC game by Acclaim, the prequel of Constructor: Street Wars
 Constructor Group AS, a Norwegian-based group specialising in shelving, racking and storage systems
 Construction worker, a builder, especially a construction company or a manager of builders

See also
 Assembler (disambiguation)
Concern (computer science). In computer science, a concern is a particular set of information that has an effect on the code of a computer program. A concern can be as general as the details of database interaction or as specific as performing a primitive calculation, depending on the level of conversation between developers and the program being discussed. IBM uses the term concern space to describe the sectioning of conceptual information.

Overview
Usually the code can be separated into logical sections, each addressing separate concerns, and so it hides the need for a given section to know particular information addressed by a different section. This leads to a modular program. Edsger W. Dijkstra coined the term "separation of concerns" to describe the mentality behind this modularization, which allows the programmer to reduce the complexity of the system being designed. Two different concerns that intermingle in the same section of code are called "highly coupled". Sometimes the chosen module divisions do not allow for one concern to be completely separated from another, resulting in cross-cutting concerns. The various programming paradigms address the issue of cross-cutting concerns to different degrees. Data logging is a common cross-cutting concern, being used in many other parts of the program other than the particular module(s) that actually log the data. Since changes to the logging code can affect other sections, it could introduce bugs in the operation of the program.

Paradigms that specifically address the issue of concern separation:

 Object-oriented programming, describing concerns as objects
 Functional programming, describing concerns as functions
 Aspect-oriented software development, treating concerns and their interaction as constructs of their own standing

See also
 Cross-cutting concern
 Separation of concerns
 Issue (computers), a unit of work to accomplish an improvement in a data system

References

External links
 Concerns in Rails, by DHH, the Rails creator

Software engineering terminology
Join point. In computer science, a join point is a point in the control flow of a program where the control flow can arrive via two different paths. In particular, it's a basic block that has more than one predecessor. In aspect-oriented programming a set of join points is called a pointcut. A join point is a specification of when, in the corresponding main program, the aspect code should be executed.

The join point is a point of execution in the base code where the advice specified in a corresponding pointcut is applied.

See also 
AspectJ, an aspect-oriented extension for the Java programming language

References

Aspect-oriented software development
Aspect-oriented programming
Control flow
Soft-skinned vehicle. In military terminology, a soft-skinned vehicle, also known as a  'B' vehicle, is a vehicle that is not protected by vehicle armour. Lexicographer Eric Partridge believed the term soft-skinned vehicle first appeared in military parlance in the early 1940s.

Soft-skinned or 'B' vehicles are often considered wheeled military vehicles such as light utility vehicles and trucks, but they can be any unarmoured wheeled or tracked vehicle that is not primarily designed to be employed for offensive purposes. They can be purpose-designed models specifically built for military service, militarised versions of commercial vehicle models or standard commercial civilian vehicles pressed into military service. In some cases this class of vehicles may be fitted with vehicle armour for crew defence.

Historically in times of war, a number of military units have converted soft-skinned vehicles into armoured fighting vehicles. One of the first units to do so was the British Royal Naval Air Service. During the First World War the Royal Naval Air Service's Armoured Car Section converted a number of cars and trucks into armoured cars and armoured lorries by adding vehicle armour and various armaments.

References