omniomni/omni-engineering huggingface dataset:
Ludvig Strigeus. Ludvig "Ludde" Strigeus (born  January 1981) is a Swedish programmer, best known for developing software such as the BitTorrent client μTorrent, OpenTTD, and Spotify.

Early life and education
Strigeus was born in January 1981, and he graduated from Chalmers University of Technology with a master's degree in computer science and engineering.

Career
He currently works as a software engineer at Spotify. In 2005, his development team won PuzzleCrack, a week-long puzzlehunt competition that combines problem-solving with computer hacking.

Ludvig Strigeus was awarded the 2006 John Ericsson (sv) Medal, the 2011 Tenzingpriset, 2015 honorary doctorate, and the 2020 Polhem Prize.  In 2023 Ludvig was elected fellow of the Royal Swedish Academy of Engineering Sciences

Personal life 
He currently resides in Gothenburg, Sweden. Due to a rare muscular disease, Strigeus uses a wheelchair.

Software 
 μTorrent - small footprint BitTorrent client for Microsoft Windows and OS X (closed-source)
 ScummVM - interpreter of adventure game engines, most notably LucasArts's SCUMM
 OpenTTD - reverse engineered game engine of Transport Tycoon, led to many ports and game improvements over the original
 Ports of Dr. Mario and Kwirk for the TI-89 calculator
 "The Idiot" - card game for Windows
 WebWorks - a text HTML editor
 Spotify - a commercial music streaming service
 Spotiamp - a lightweight Spotify Premium client for Windows, created as a tribute to Winamp
 TunSafe - VPN client for Windows using the WireGuard protocol

References

External links 
 SourceForge profile
 Patents by Inventor Ludvig Strigeus at Justia Patents

Video game programmers
Swedish computer programmers
Chalmers University of Technology alumni
1981 births
Living people
Spotify people
Mehdi Vaez-Iravani. Mehdi Vaez-Iravani is an Iranian scientist, engineer and inventor involved in the invention of "Shear-force microscopy".

Mehdi Vaez-Iravani graduated with a PhD in Electrical engineering from University College London and became a faculty member at Rochester Institute of Technology before joining KLA Tencor.

He has numerous patents and scientific publications in optics, optical engineering and related areas. He attended Alborz High School in Tehran, Iran from 1971 to 1975.

Selected bibliography

References

Iranian electrical engineers
Year of birth missing (living people)
Living people
Electronic kit. An electronic kit is a package of electrical components used to build an electronic device.  Generally, kits are composed of electronic components, a circuit diagram (schematic), assembly instructions, and often a printed circuit board (PCB) or another type of prototyping board.

There are two types of kits. Some build a single device or system. Other types used for education demonstrate a range of circuits. These will include a solderless construction board of some type, such as:
 Components mounted in plastic blocks with side contacts, that are held together in a base, e.g. Denshi blocks
 Springs on a card board, the springs trap wire leads, or component leads, such as Philips EE electronic experiment kits. These are a cheap and flexible option
 Professional type prototyping boards, (breadboards) into which component leads are inserted, following documentation of the "kit".

The first type of kit for constructing a single device normally uses a PCB on which components are soldered. They normally come with extended documentation describing which component goes where into the PCB.

For advanced hobby projects, sometimes the kit may only consist of a printed circuit board and assembly instructions, and the purchaser may have to source all the parts independently; or, the vendor may provide hard-to-get or pre-programmed parts while expecting the purchaser to obtain the rest of the components.

People primarily purchase electronic kits to have fun and learn how things work. They were once popular as a means to reduce the cost of buying goods, but there is usually no cost saving in buying a kit today.

Some electronic kits were assembled to make complete complex devices such as color television sets, oscilloscopes, high-end audio amplifiers, amateur radio equipment, electric organs,   and even computers such as the Heathkit H-8, and the LNW-80.  Many of the early microprocessor computers were sold as either electronic kits or assembled and tested. Heathkit sold millions of electronic kits during its 45-year history.

Home assembly of common consumer electronics items no longer provides a cost advantage over commercially manufactured and distributed devices. People still build kits for custom devices and special-purpose electronics for professional and educational use and as a hobby.

Also emerging is a trend to simplify the complexity by providing preprogrammed or modular kits often provided by many suppliers online. The fun and thrill of making your own electronics have shifted, in many cases, from easy-to-comprehend applications and analog devices to more sophisticated digital devices.


Examples
 The Altair 8800 (the first home computer) was also sold as a kit, as were the MK14, Sinclair ZX80, Sinclair ZX81 and Acorn Atom computers.
 Many S-100 bus system cards were sold only as kits.
 Building a Robot kit, most often with a micro controller inside, is now in fashion.

See also
 Maker culture

References

Further reading
 Dostál, J. Electronic kits in education. Olomouc, EU: Votobia, 2008. 74 s. .

Hobbies
Electronics
Bristol Type 143. The Bristol Type 143 was a British twin-engine monoplane aircraft designed by Frank Barnwell of the Bristol Aeroplane Company.

Developed alongside the more famous Bristol Type 142, which was developed into the Blenheim light bomber, it used the same wing design and employed the same advanced (for the day) design features such as stressed skin, flaps, and retractable undercarriage. The engine it was designed to use never entered production and only a single prototype was manufactured,

Design and development
Like the better-known Type 142 the Type 143 arose from the unbuilt Bristol Type 135 proposal for a civil twin-engine light transport aircraft. This was a low-wing twin-engined monoplane, seating six people and a crew of two, first sketched out by Frank Barnwell, with the intention of using the smaller of the two engines then being developed by Roy Fedden, the Aquila I. Although the manufacture of a second Aquila was authorised, nothing was done about the construction of an actual airframe. Meanwhile, in early 1934 Lord Rothermere announced his intention to have 'the fastest civil aircraft in Europe' built for him. Barnwell proposed an aircraft based on the type 135 but using the more powerful Mercury engine in place of the Aquila, and this was accepted by Rothermere, the aircraft being ordered on 26 March 1934 and first flying on 12 April 1935.

The Type 143 was very similar to the Type 135 design, although the cabin was enlarged to seat eight and some detail changes were made to optimise the use of common components with the Type 142: over 70% of components were shared. The prototype 143 was accordingly built alongside the Type 142, receiving the civil registration G-ADEK on 22 March 1935 but had to wait until the end of the year before the engines had completed trials. It was first flown on 20 January 1936 without registration but bearing the mark R 14. Further flying continued at Filton, mainly as a testbed for the Aquila. It was put into storage when Aquila development was abandoned in 1938 and subsequently scrapped.

Specifications (Type 143)

See also

References

Citations

Bibliography

External links
Type 143
Type 142

Type 143
1930s British civil utility aircraft
Low-wing aircraft
Aircraft first flown in 1936
Twin piston-engined tractor aircraft
MG J-type. The MG J-type is a sports car that was produced by MG from 1932 to 1934.  This 2-door sports car used an updated version of the overhead camshaft, crossflow engine, used in the 1928 Morris Minor and Wolseley 10 and previously fitted in the MG M-type Midget of 1929 to 1932, driving the rear wheels through a four-speed non-synchromesh gearbox. The chassis was from the D-Type with suspension by half-elliptic springs and Hartford friction shock-absorbers all round with rigid front and rear axles.  The car had a wheelbase of  and a track of .  Most cars were open two-seaters, but a closed salonette version of the J1 was also made, and some chassis were supplied to external coachbuilders.  The open cars can be distinguished from the M type by having cut-away tops to the doors.



J1

The J1 was the four-seat car in the range. The engine was the 847 cc unit previously seen in the C-type with twin SU carburetors giving 36 bhp.  The car cost £220 in open and £225 in Salonette form.

J2

The J2, a road-going two-seater, was the commonest car in the range.  Early models had cycle wings, which were replaced in 1933 by the full-length type typical of all sports MGs until the 1950s TF. The top speed of a standard car was , but a specially prepared one tested by The Autocar magazine reached . The car cost £199.

The most serious of the J2's technical failings is that it has only a two-bearing crankshaft which may break if over-revved. The overhead camshaft is driven by a vertical shaft through bevel gears, which also forms the armature of the dynamo. Thus any oil leak from the cambox seal goes into the dynamo brushgear, presenting a fire hazard.

Rather than hydraulic brakes the car has Bowden cables to each drum. Although requiring no more pedal force than any other non-power-assisted drum brake if they are well maintained, the drums themselves are small, and even in-period it was a common modification to replace them with larger drums from later models.

J3

The J3 was a racing version with the engine capacity reduced to 746 cc by shortening the stroke from 83 to 73 mm and fitted with a Powerplus supercharger. The smaller engine capacity was to allow the car to compete in 750 cc class racing events. Larger brakes from the L-type were fitted.

J4

The J4 was a pure racing version with lightweight body work and the J3 engine, but using more boost from the supercharger to obtain .

References

External links

 www.mgjtype.com- 

J-type
Cars introduced in 1932
1930s cars
24 Hours of Le Mans race cars
John Kennedy Barton. John Kennedy Barton (April 7, 1853 – December 23, 1921) was a rear admiral in the United States Navy.

Biography 
Born in Philadelphia, Barton graduated from the United States Naval Academy in 1873. He alternated tours of duty afloat and ashore through the 1880s, serving in such ships as , , , , before teaching steam engineering at the Naval Academy from 1882 to 1886. Barton then served three years on the Asiatic Station, on  and , before returning to the Naval Academy for another tour of duty as instructor (1889–1893).

After supervising the fitting out of the gunboat  and cruiser , Barton became a chief engineer on January 15, 1895. He served in the Pacific Fleet on  and  until detached to shore duty in 1897. Barton returned to the Asiatic Station in 1900 and served on the cruiser  and the battleship  before becoming fleet engineer in 1903. Relieved shortly afterward, he again taught at the Naval Academy until 1905 and then did graduate work in engineering.

In 1907 Barton became head of the department of steam engineering at the Philadelphia Navy Yard. On December 21, 1908, he assumed the title of engineer-in-chief as Chief of the Bureau of Steam Engineering with the rank of rear admiral. Only two days later, Barton was detached to return home due to illness and was simultaneously transferred to the navy's retired list. He subsequently held a post on a Naval Examining Board in January 1909, and also served in the Civil Service Commission. He died at the Naval Hospital at League Island, Philadelphia, on December 23, 1921.

Two ships have been named  for him.

External links 

1853 births
1921 deaths
Military personnel from Philadelphia
United States Naval Academy alumni
United States Navy rear admirals (lower half)
Matthew Hennessy. Matthew Hennessy is an Irish computer scientist who has contributed especially to concurrency, process calculi and programming language semantics.

Career
During 1976–77, Matthew Hennessy was an assistant professor at the University of Waterloo in Canada. Then during 1977–78, he was a visiting professor at the Universidade Federal de Pernambuco in Brazil. Subsequently, he was a research associate (1979–81) and then lecturer (1981–85) at the University of Edinburgh in Scotland. During 1985, he was a guest lecturer/researcher at the University of Aarhus in Denmark.

Hennessy was Professor of Computer Science at the Department of Informatics, University of Sussex, England, from 1985 until 2008. Since then, Hennessy has held a research professorship at the Department of Computer Science, Trinity College, Dublin.

Hennessy's research interests are in the area of the semantic foundations of programming and specification languages, particularly involving distributed computing, including mobile computing. He also has an interest in verification tools. His co-authors include Robin Milner and Gordon Plotkin.

Hennessy is a member of the Academy of Europe. He held a Royal Society/Leverhulme Trust Senior Research Fellowship during 2005–06 and has a
Science Foundation Ireland Research Professorship at Trinity College Dublin.

Books
Matthew Hennessy has written a number of books:

 Hennessy, Matthew. A Distributed Pi-Calculus. Cambridge University Press, Cambridge, UK, 2007. .
 Hennessy, Matthew. Algebraic Theory of Processes. The MIT Press, Cambridge, Massachusetts, 1988. .
 Hennessy, Matthew. The Semantics of Programming Languages: An Elementary Introduction using Structural Operational Semantics. John Wiley and Sons, New York, 1990. .

See also
 Hennessy–Milner logic
 Ó hAonghusa

References

External links
 Matthew Hennessy Trinity College Dublin home page
 

Year of birth missing (living people)
Living people
20th-century Irish people
21st-century Irish people
Irish computer scientists
Formal methods people
Computer science writers
Academic staff of the University of Waterloo
Academics of the University of Edinburgh
Academics of the University of Sussex
Fellows of Trinity College Dublin
1292 Advanced Programmable Video System. The 1292 Advanced Programmable Video System is a second-generation home video game console released by European company Audiosonic in 1978. It is part of a group of software-compatible consoles which include the Interton VC 4000 and the Voltmace Database. The 1292 Advanced Programmable Video System included its power pack inside the console instead of an exterior power pack.

Specifications

 CPU: 8-bit Signetics 2650AI at 0.887 MHz
 Programmable video interface: Signetics 2636N at 3.58 MHz. This chipset was less powerful than the later model Signetics 2637N used in the Arcadia 2001.
 Data Memory: 43 bytes

Graphics
 Sprites: 4 single colour sprites (1 can be 8 colours)
 1 score line displaying 4 BCD digits
 Background consisting of a series of alternating lines

Misc
 The early games cartridges used a 2 KB ROM, later ones, such as Activision branded ones, up to 8 KB
 Very basic arcade machine sound

User programming
An expensive (£49 in the UK in 1977) Hobby Module was available which gave 6.5 kilobits of user-programmable memory and had a 5-pin DIN socket to allow software to be saved to a cassette tape player. This converted the unit into halfway between a home computer and an ordinary gaming console.

The user had to be familiar with programming in Signetics 2650 assembly language and the unconventional ways and register architecture of the Signetics 2650 processor.

Released versions
The console was produced by different companies and sold with different names. Although all variants have identical computational hardware, changes to the dimensions of the cartridge slot on some variants result in cartridges not always being interchangeable between systems. The following is a table of the console variants grouped by cartridge compatibility.

Games
Although, not much information is known about the release dates of the cartridges, the total number of the games should be 59 (33 games released by Radofin between 1977 and 1978, 19 games for the Interton VC 4000 and compatibles after 1978, and 7 more games released around 1980).

References

External links
 IGDB.com entry & 1292 APVS games list (With accurate explanation for misconception of the earlier 1976 release)
 SHAMELESSLIFE wordpress blog entry for details for 1292 APVS & Interton VC 4000
 Video Game Console Library entry for the 1292 APVS / VC 4000 family
 Arcade Italia entry for MAME compatibility
Museo del Videojuego Radofin 1292 and 1392 information and game list in Spanish

Discontinued video game consoles
Home video game consoles
Second-generation video game consoles
Products introduced in 1978
Park Patrol. Park Patrol is a video game designed by Tony Ngo and game published in 1984 by Activision for the Commodore 64. It was later released for the Amstrad CPC and ZX Spectrum. Players control a park ranger with a choice of a male or female character. The goal is to tidy up rubbish from the waters of the lake and the shoreline.

Gameplay
The ranger can walk on the shore or use an inflatable dinghy with an outboard motor to go into the water.

Turtles kill on contact. If one falls into the water it can be rescued for points but turn into a fast-moving green turtle if left for too long.

Snakes lurk in the water and can puncture the dinghy. They can be scared away temporarily by dropping snake repellent (at the cost of energy).

Swimmers can be rescued when calling for help.

Ants steel food from the hut, which can be recovered by bumping into them from the side (and killed by knocking them into the water).

On the shore is the ranger's hut, which contains food to top up energy. A plant near the hut grows every time the ranger walks into it. When it flowers, the ranger gets a short period of immunity.

By approaching at the right angle, the ranger can jump out of the dinghy and land on floating logs, starting a logrolling mini-game.

Once all the litter is collected, a bonus is awarded based on energy remaining.

External links

Park Patrol at GameFAQs

1984 video games
Activision games
Amstrad CPC games
Commodore 64 games
Telecomsoft games
ZX Spectrum games
Single-player video games
Video games with gender-selectable protagonists
Video games developed in the United States
Corrugator. Corrugator may refer to:
 Corrugator supercilii muscle, a small, narrow, pyramidal muscle close to the eye
 Corrugator cutis ani muscle, after the anatomist George Viner Ellis
 Machinery used to manufacture corrugated fiberboard used in boxes
 Machine which is used to produce corrugated stainless steel tubing

See also 
 Corrugated (disambiguation)
Colored fire. Colored fire is a common pyrotechnic effect used in stage productions, fireworks and by fire performers the world over. Generally, the color of a flame may be red, orange, blue, yellow, or white, and is dominated by blackbody radiation from soot and steam. When additional chemicals are added to the fuel burning, their atomic emission spectra can affect the frequencies of visible light radiation emitted - in other words, the flame appears in a different color dependent upon the chemical additives. Flame coloring is also a good way to demonstrate how fire changes when subjected to heat and how they also change the matter around them.

To color their flames, pyrotechnicians will generally use metal salts. Specific combinations of fuels and co-solvents are required in order to dissolve the necessary chemicals. Color enhancers (usually chlorine donors) are frequently added too, the most common of which is polyvinyl chloride. A practical use of colored fire is the flame test, where metal cations are tested by placing the sample in a flame and analyzing the color produced.

Flame colorants

Emitted colors depend on the electronic configuration of the elements involved. Heat energy from the flame excites electrons to a higher quantum level, and the atoms emit characteristic colors (photons with energies corresponding to the visible spectrum) as they return to lower energy levels

Campfire colorants

Flame colorants are becoming popular while camping. Scouts  and other outdoor enthusiasts have placed sections of copper pipe with holes drilled throughout and stuffed with garden hose onto campfires to create a variety of flame colors.  An easier method of coloring campfires has been fueled by commercial products.  These packages of flame colorants are tossed onto a campfire or into a fireplace to produce effects.

Although these chemicals are very effective at imparting their color into an already existing flame, these substances are not flammable alone. To produce a powder or solid that, when lit, produces a colored flame, the necessary steps are more complex. To get a powder to burn satisfactorily, both a fuel and oxidizer will mostly be needed. Common oxidizers include.

 Ammonium perchlorate
 Ammonium nitrate
 Barium chlorate
 Potassium nitrate (saltpeter)
 Potassium chlorate
 Potassium perchlorate
 Strontium nitrate
 Sodium nitrate

Many of these oxidizers also produce a colored flame by themselves. Some of them - as well as the main colorants - are severely toxic and therefore environmentally damaging.

See also
 Color temperature

References 

Pyrotechnics
Redundant code. In computer programming, redundant code is source code or compiled code in a computer program that is unnecessary, such as:
 recomputing a value that has previously been calculated and is still available,
 code that is never executed (known as unreachable code),
 code which is executed but has no external effect (e.g., does not change the output produced by a program; known as dead code).

A NOP instruction might be considered to be redundant code that has been explicitly inserted to pad out the instruction stream or introduce a time delay, for example to create a timing loop by "wasting time".  Identifiers that are declared, but never referenced, are termed redundant declarations.

Examples
The following examples are in C.

int foo(int iX)
{
    int iY = iX*2;

    return iX*2;
}

The second iX*2 expression is redundant code and can be replaced by a reference to the variable iY. Alternatively, the definition int iY = iX*2 can instead be removed.

Consider:

#define min(A,B) ((A)<(B)?(A):(B))

int shorter_magnitude(int u1, int v1, int u2, int v2)
{
    /* Returns the shorter magnitude of (u1,v1) and (u2,v2) */
    return sqrt(min(u1*u1 + v1*v1, u2*u2 + v2*v2));
}

As a consequence of using the C preprocessor, the compiler will only see the expanded form:

int shorter_magnitude(int u1, int v1, int u2, int v2)
{
    int temp;
    if (u1*u1 + v1*v1 < u2*u2 + v2*v2)
        temp = u1*u1 + v1*v1; /* Redundant already calculated for comparison */
    else
        temp = u2*u2 + v2*v2; /* Redundant already calculated for comparison */
    return sqrt(temp);
}

Because the use of min/max macros is very common, modern compilers are programmed to recognize and eliminate redundancy caused by their use.

There is no redundancy, however, in the following code:
#define max(A,B) ((A)>(B)?(A):(B))

int random(int cutoff, int range)
{
    return max(cutoff, rand()%range);
}

If the initial call to rand(), modulo range, is greater than or equal to cutoff, rand() will be called a second time for a second computation of rand()%range, which may result in a value that is actually lower than the cutoff.  The max macro thus may not produce the intended behavior for this function.

See also
 Code bloat
 Code reuse
 Common subexpression elimination
 Don't repeat yourself
 Duplicate code
 Redundancy

References

Compiler optimizations
Software anomalies
Source code