omniomni/omni-engineering huggingface dataset:
Stimulus protocol. In telephony, a stimulus protocol is a type of protocol that is used to carry event notifications between end points. Such a protocol is used to control the operation of devices at each end of the link. However a stimulus protocol is not sensitive to the system state. In a typical application such a protocol will carry keystroke information from a telephone set to a central call control. It may also carry control information for simple types of text displays. MiNET from Mitel is a typical protocol of this sort.

Stimulus protocols are most suited to networks with dumb peripherals and intelligent centralized applications (see intelligent network). This is in contrast to functional protocols which are best suited to a network with an intelligent periphery and a dumb core (see dumb network). Because these architectures share core hardware over large numbers of peripherals, large and expensive computing capabilities in terms of both hardware and software may be supplied. These centralized architectures excel in solving the problems of complexity for large scale applications since the investment in hardware and software may be amortized across a great many users. However the same virtue of large scale sharing prevents these architectures from providing any significant degree of customization to the preferences of the individual user. The most that can be supplied is a degree of parameterization of service operation.

With their suitability tied to the virtues of centralized network architectures, stimulus protocols are being deprecated in favor of functional protocols with the rise of the Internet. A functional protocol such as  Session Initiation Protocol (SIP) from the IETF is more suited for Internet applications.

Network protocols
Telephony
1817 in rail transport. 

Events
Approximate date – Britain's longest tramroad tunnel is opened at Pwll du near Blaenavon in South Wales. The Pwll Du Tunnel is more than a mile (2400 m) in length. Begun as a mineral adit, at this time it carries a horse-drawn double track plateway of approximately 2 ft (600 mm) gauge carrying material for Blaenavon Ironworks; next summer it will be incorporated in Thomas Hill's Tramroad.

Births

March births 
 March 26 - Herman Haupt, United States railroad civil engineer (d. 1905).

June births 
 June 20 - Silas Seymour, chief engineer and/or consulting engineer for several railroads in New York in the mid- to late 19th century (d. 1890).

July births 
 July 1 – Hugh J. Jewett, president of the Erie Railroad 1874–1884 (d. 1898).
 July 15 – John Fowler, British civil engineer (d. 1898).

October births 
 October 2 – Webster Wagner, founder of Wagner Palace Car Company (d. 1883).
 October 17 – Alexander Mitchell, president of Chicago, Milwaukee and St. Paul Railway 1864–1887 (d. 1887).

Unknown date births
 Matthew Baird, second owner of Baldwin Locomotive Works (d. 1877)
 Walter McQueen, Chief mechanical engineer for the Albany and Schenectady Railroad 1845–1850, Hudson River Railroad 1850–1852, and superintendent of Schenectady Locomotive Works 1852–1876 (d. 1893).

Deaths

References
Hahn Hi-Boy. A Hahn Hi-Boy is a specialized, high-clearance type of farm crop chemical applicator designed to operate in high crops without damaging them.  The largest producer of hi-boys is Hagie Manufacturing Company of Clarion, Iowa, United States.  The most common uses of Hi-Boy are for detasseling, spraying herbicides, and applying glyphosate directly to weeds growing above crop height with a wick or wiper.

Agricultural machinery

The Hahn Hi-Boy was invented by Lloyd Hahn in Evansville in an undisclosed time in the 1940s
Swing yarder. A swing yarder is a mobile piece of heavy duty forestry equipment used for pulling logs from the woods to a logging road with cables.  The swing yarder is also known as a grapple yarder.

In any logging operation, it is necessary to transport the harvested tree from the stump to a landing for transport to market (usually on a truck). If the ground is relatively flat it may be possible to transport the tree or logs cut from the tree on a wheeled or tracked machine. However, if the ground is too steep for the operation of such machinery, it is common practice to rig some sort of a cable system for moving the wood.  The swing yarder is one of several varieties of machines that have been used for this purpose.

The swing yarder has several drums to pull in the cables. The cables run up an angled boom and then to the far side of a setting.  By using two cables set up like a clothes line, the rigging can be pulled out and logs can be pulled across a logging setting where the trees have been previously felled.  This machine is most suitable for steep ground where it is difficult to access the logs with other machinery.  Swing yarders can also be used in flatter areas with lighter loads.

While there are various rigging options, the most common one uses a grapple that can be lowered onto a logs and closed via the cable system.  Using a grapple avoids the need for people in the setting to attach chokers to the log.  Choker setting as a profession is a very dangerous occupation.

The main difference between a swing yarder and a tower yarder is that the upperworks is mounted on a large slewing bearing.  This bearing permits the boom and cable system to be 'swung' across a setting without relocating the machine.  An experienced operator uses timing and cable tension to swing the grapple to the desired location. In practice, however, the main benefit of a swinging machine is that once the logs are yarded up to the machine, they can be swung to the side and landed. This allows the machine to be positioned in a small area such as on a road, and to land (set down) the logs on the road behind (or in front of) the machine.  By contrast a tower has no options on where to set the logs---so the tower has to be positioned back from the break of the hill so as to leave a landing area on the downhill side of the machine, the logs can only be pulled up to near the tower and then lowered to the ground making it necessary for a shovel (log loader) to also be present to remove the logs once landed. Implicitly a swing machine does not need to be as tall as a tower machine particularly in steep ground because the swing machine can be set right up to the 'edge' of the steep ground while the tower must be set back from the 'edge' to allow landing space.

External links
Washington TL-6 Swing yarder

Log transport
Forestry equipment
Bart Preneel. Bart Preneel (born 15 October 1963 in Leuven, Belgium) is a Belgian cryptographer and cryptanalyst. He is a professor at Katholieke Universiteit Leuven, in the COSIC group.

He was the president of the International Association for Cryptologic Research in 2008–2013 and project manager of ECRYPT.

Education 
In 1987, Preneel received a degree in Electrical Engineering from the Katholieke Universiteit, Leuven.

In 1993, Preneel received a PhD in Applied Sciences from the Katholieke Universiteit Leuven. His dissertation in computer science, entitled Analysis and Design of Cryptographic Hash Functions, was advised by Joos (Joseph) P. L. Vandewalle and René J. M. Govaerts.

Career 
Along with Shoji Miyaguchi, he independently invented the Miyaguchi–Preneel scheme, a structure that converts a block cipher into a hash function, used eg. in the hash function Whirlpool. He is one of the authors of the RIPEMD-160 hash function. He was also a co-inventor of the stream cipher MUGI which would later become a Japanese standard, and of the stream cipher Trivium which was a well-received entrant to the eSTREAM project.

He has also contributed to the cryptanalysis of RC4, SOBER-t32, MacGuffin, Helix, Phelix, Py, TPypy, the HAVAL cryptographic hash function, and the SecurID hash function.

References

External links
 Home page

Living people
1963 births
Belgian cryptographers
Flemish scientists
Academic staff of KU Leuven
Modern cryptographers
Proper orthogonal decomposition. The proper orthogonal decomposition is a numerical method that enables a reduction in the complexity of computer intensive simulations such as computational fluid dynamics and structural analysis (like crash simulations). Typically in fluid dynamics and turbulences analysis, it is used to replace the Navier–Stokes equations by simpler models to solve. 

It belongs to a class of algorithms called model order reduction (or in short model reduction). What it essentially does is to train a model based on simulation data. To this extent, it can be associated with the field of machine learning.

POD and PCA 
The main use of POD is to decompose a physical field (like pressure, temperature in fluid dynamics or stress and deformation in structural analysis), depending on the different variables that influence its physical behaviors. As its name hints, it's operating an Orthogonal Decomposition along with the Principal Components of the field. As such it is assimilated with the principal component analysis from Pearson in the field of statistics, or the singular value decomposition in linear algebra because it refers to eigenvalues and eigenvectors of a physical field. In those domains, it is associated with the research of Karhunen and Loève, and their Karhunen–Loève theorem.

Mathematical expression 
The first idea behind the Proper Orthogonal Decomposition (POD), as it was originally formulated in the domain of fluid dynamics to analyze turbulences, is to decompose a random vector field u(x, t) into a set of deterministic spatial functions Φk(x) modulated by random time coefficients ak(t) so that:

The first step is to sample the vector field over a period of time in what we call snapshots (as display in the image of the POD snapshots). This snapshot method is averaging the samples over the space dimension n, and correlating them with each other along the time samples p:

 with n spatial elements, and p time samples

The next step is to compute the covariance matrix C

We then compute the eigenvalues and eigenvectors of C and we order them from the largest eigenvalue to the smallest.

We obtain n eigenvalues λ1,...,λn and a set of n eigenvectors arranged as columns in an n × n matrix Φ:

References

External links 
 MIT: http://web.mit.edu/6.242/www/images/lec6_6242_2004.pdf
 Stanford University - Charbel Farhat & David Amsallem https://web.stanford.edu/group/frg/course_work/CME345/CA-CME345-Ch4.pdf
 Weiss, Julien: A Tutorial on the Proper Orthogonal Decomposition. In: 2019 AIAA Aviation Forum. 17–21 June 2019, Dallas, Texas, United States.
French course from CNRS https://www.math.u-bordeaux.fr/~mbergman/PDF/OuvrageSynthese/OCET06.pdf
Applications of the Proper Orthogonal Decomposition Method http://www.cerfacs.fr/~cfdbib/repository/WN_CFD_07_97.pdf

 
Continuum mechanics
Numerical differential equations
Partial differential equations
Structural analysis
Computational electromagnetics
AMULET (processor). AMULET is a series of microprocessors implementing the ARM processor architecture.  Developed by the Advanced Processor Technologies group at the Department of Computer Science at the University of Manchester (formerly the AMULET and PAL groups based at the same institution), AMULET is unique amongst ARM implementations in being an asynchronous microprocessor, not making use of a square wave clock signal for data synchronization and movement.

List of AMULET microprocessors 
AMULET1 — Designed in 1990 and first fabricated in 1993.  Its estimated performance is approximately 70% of that of a comparably-sized synchronous ARM6 running at 20 MHz.
AMULET2 — A re-implementation of AMULET1 first fabricated in 1996.  Features on-chip memory that can be used either as processor cache or mapped RAM.  The APT group estimates AMULET2 to have a similar power dissipation/performance ratio as ARM8.  One very notable feature due to the asynchronous design is the drop of power dissipation to 3 μW when not in use (assuming the on-board timer, which handles DRAM refresh, is also inactive).
AMULET3 — This was a redesigned architecture aiming at higher performance than the previous AMULET processors whilst retaining low power dissipation.  Fabricated in 2000, it supported the ARM level 4 instruction set compatibility, alongside support for Thumb mode (i.e. ARM9TM). Performance and power dissipation were approximately the same as an ARM9 fabricated on the same technology.  AMULET3 was employed in a commercial prototype DECT device because of its inherent low electromagnetic interference characteristics.  This did not go into manufacture for non-technical reasons.

See also
ARM architecture

References

External links
ARM Ltd.
APT Group

ARM processors
Department of Computer Science, University of Manchester
British Airways Maintenance Cardiff. British Airways Maintenance Cardiff (BAMC), also known as British Airways Maintenance is a major aircraft maintenance facility located at Cardiff Airport and a wholly-owned subsidiary of British Airways and part of British Airways Engineering. It carries out heavy maintenance on all of British Airways Boeing long haul aircraft.

History
In June 1990, a proposal was made to build a £70m hangar for maintenance of the BA 747 fleet at Cardiff Airport to employ 1,200 people. It was formally opened in June 1993. From February 2008, BAMC also maintained Boeing 767-300 series aircraft for BA whilst a further advance in capability has seen the introduction of Boeing 777-200ER/LR and Boeing 777-300ER aircraft from July 2010. The hangar also has the capability to handle a Boeing 787.

Structure
It has a three-bay hangar with two additional 'Nose In' facilities for interior modifications. It is based at Tredogan near Rhoose in the Vale of Glamorgan. BAMC employs in excess of 650 people, in three main departments:

 Production
 Planning & Materials 
 Compliance

Other BA operations in the area included British Airways Avionic Engineering at Pontyclun, Rhondda Cynon Taff, and British Airways Interiors Engineering in Blackwood, Caerphilly.In 2022 all three subsidiaries were brought under one roof at the BAMC facility at Cardiff airport and was renamed to British Airways Engineering Wales (BAEW).

External links
 Interserve
 Maintenance building
 History of British Airways 
 British Airways Boeing 747-400 in D-Check (YouTube)

Aerospace companies of the United Kingdom
Companies based in Cardiff
Organisations based in the Vale of Glamorgan
British Airways
Companies established in 1993
1993 establishments in Wales
Aircraft maintenance companies
HALCA. HALCA (Highly Advanced Laboratory for Communications and Astronomy), also known for its project name VSOP (VLBI Space Observatory Programme), the code name MUSES-B (for the second of the Mu Space Engineering Spacecraft series), or just Haruka () was a Japanese 8 meter diameter radio telescope satellite which was used for Very Long Baseline Interferometry (VLBI). It was the first such space-borne dedicated VLBI mission.

History
It was placed in a highly elliptical orbit with an apogee altitude of 21,400 km and a perigee altitude of 560 km, with an orbital period of approximately 6.3 hours. This orbit allowed imaging of celestial radio sources by the satellite in conjunction with an array of ground-based radio telescopes, such that both good (u,v) plane coverage and very high resolution were obtained.

Although designed to observe in three frequency bands: 1.6 GHz, 5.0 GHz, and 22 GHz, it was found that the sensitivity of the 22 GHz band had severely degraded after orbital deployment, probably caused by vibrational deformation of the dish shape at launch, thus limiting observations to the 1.6 GHz and 5.0 GHz bands.

HALCA was launched in February 1997 from Kagoshima Space Center, and made its final VSOP observations in October 2003, far exceeding its 3-year predicted lifespan, before the loss of attitude control. All operations were officially ended in November 2005.

A follow-up mission ASTRO-G (VSOP-2) was planned, with a proposed launch date of 2012, but the project was eventually cancelled in 2011 due to increasing costs and the difficulties of achieving its science goals. It was expected to achieve resolutions up to ten times higher and up to ten times greater sensitivity than its predecessor HALCA.

The cancellation of ASTRO-G left the Russian Spektr-R mission as the only then operational space VLBI facility. Spektr-R stopped operating in 2019.

Antenna 
The large 8 meter antenna was designed to unfold in space as the unfolded configuration did not fit inside the rocket fairing. The antenna was a metal mesh of 6000 cables. To form an ideal shape the length of the cables were adjusted on the backside of the antenna. One concern was that the cables could entangle. The deployment of the main reflector started on February 27, 1997. The deployment was done over three hours on the first day and was completed in 20 minutes during the next day.

Highlights
Observations of hydroxyl masers and pulsars at 1.6 GHz
Detection of interference fringes for quasar PKS1519-273 between HALCA and terrestrial radio telescopes
Routines imaging of quasars and radio galaxies etc. by means of experimental VLBI observations with HALCA and terrestrial radio telescope networks

Gallery

References

External links

 HALCA
 VSOP 

Radio telescopes
Space telescopes
Satellites of Japan
Spacecraft launched in 1997
Sun printing. Sun printing may refer to various printing techniques which use sunlight as a developing or fixative agent.

Techniques

Cyanotype

Cyanotype, also referred to as "blueprinting", is the oldest non-silver photographic printing process. It involves exposing materials which have been treated with a solution of potassium ferricyanide and ferric ammonium citrate to a UV light source such as the sun. Negative or positive images can be obtained by blocking UV light from reaching the sensitized material. For example, a negative image can be produced by placing a leaf upon paper treated with this solution and exposing to sunlight for 10 to 20 minutes. The paper will retain the image of the leaf after it has been rinsed with water. Once the paper dries, parts that were exposed to the sun will turn a shade of Prussian blue (ferric ferrocyanide), while parts that were covered by the leaf will remain white.

Light-sensitive vat dyes

A specialized type of vat dye called Inkodye is also used for sun-printing due to its light-sensitive quality. Unlike other vat dyes which use oxygen to develop their color, Inkodyes are developed by light. These dyes are suspended in leuco form appearing colorless until they are exposed to UV. Their usage resembles that of cyanotype, but unlike cyanotype Inkodyes are primarily used on textiles and exist in a full range of colors. Exposure times vary from 3 to 15 minutes depending on the desired color and intensity of light. Once exposed, the sensitized material is washed in soapy water to remove dye from unexposed areas. Such dyes are typically used by craftspeople, fabric printers and artists and can be printed with photographic negatives, resist paste or through a silk screen.

Potassium dichromate

Sun printing may also refer to a photographic process using potassium dichromate which produces a negative plate for conventional lithographic printing. The process uses a film of gelatine spread on a flat and rigid surface. This is coated with a dilute solution of potassium dichromate and dried in low light conditions.  A translucent positive is secured in tight contact with the treated gelatine layer and exposed to bright sunlight for a period of up to 30 minutes. During this time the sunlight and potassium dichromate tan the gelatine exposed to light. The plate is developed by washing in warm water and removing the untanned gelatine. Once dry, a relief print is revealed on the plate. The surface can be inked and printed in a hand press to produce any number of identical prints of the original subject.

References

Further reading

External links
 Inkodye - Light-sensitive vat dyes

Photographic processes
Non-impact printing
Printmaking
Limited availability. When customers of a public switched telephone network make telephone calls, they utilize a telecommunications network called a switched-circuit network. In a switched-circuit network, devices known as switches are used to connect the calling party to the called party. Each switch has a number of inlets and outlets, and by connecting a specific inlet to the correct outlet, each switch helps to complete an end-to-end circuit between users. This method is used in, for example graded multiple banks of selectors.

In a modern circuit-switched network, switches can connect any inlet to any outlet; this is known as full availability.

References

 Kennedy I., Lost Call Theory, Lecture Notes, ELEN5007: Teletraffic Engineering, School of Electrical and Information Engineering, University of the Witwatersrand, 2005.
 Akimaru H., Kawashima K., Teletraffic: Theory and Applications, Springer-Verlag London, 2nd Ed., 1999, p 6.
 Farr R.E., Telecommunications Traffic, Tariffs and Costs: An Introduction For Managers, Peter Peregrinus, 1988, p 90.

Notes 

Telephone exchanges
AMS Neve. AMS Neve Ltd is a privately owned audio engineering company who specialise in digital and analogue music consoles, outboard equipment and post production consoles. AMS Neve was the result of the amalgamation in 1992 of AMS (Advanced Music Systems) with Neve Electronics.

Background
Neve Electronics was a British manufacturer of mixing consoles that originated in the work of Rupert Neve in the 1960s. Neve analogue consoles have been considered to be of such high quality that many of twenty or thirty years of age are still in use today at recording studios around the world—even as digital audio has taken over many aspects of recording technology.  Studios with Neve equipment are often sought out by musicians. Models such as the '1073' and '1081' microphone preamps are still among the most popular and expensive in the recording world.

Neve was the first company to develop computer-controlled moving fader automation, NECAM, in the mid-1970s. 

In 1985 Neve Electronics was acquired by the Siemens group; in 1992 the Siemens group combined Neve Electronics with another newly acquired company, Advanced Music Systems to form AMS Neve. Today, the company produces both digital and analogue systems, marketing digital products under the AMS Neve brand, and analogue products under the Neve brand.

Awards
AMS Neve won a Technical Grammy Award in 2000. The company has also won Oscar and Emmy awards.

Notable products
Analogue Consoles:
 Neve 88R and 88RS Large-format analogue consoles
 Neve Genesys and Genesys Black
Neve BCM10/2

Digital Consoles:
 AMS Neve DFC (Digital film console)
 AMS Neve MMC/DMC (Multimedia consoles)

Outboard:
 8801 Channel Strip (based on the Channel strip of the aforementioned 88R/88RS console)
 Neve 8816 Summing Mixer/8804 Fader Pack
 Neve 88RLB/1073LB/1073LBEQ/2264ALB  API-format 500 Series "Lunchbox" modules
 Neve 1073/1081 Re-issues
 33609JD Stereo Compressor

References

External links
AMS Neve

Audio mixing console manufacturers
Companies based in Burnley
Electronics companies established in 1992
Manufacturing companies of England