omniomni/omni-engineering huggingface dataset:
Enumerator (computer science). An enumerator is a Turing machine with an attached printer. The Turing machine can use that printer as an output device to print strings. Every time the Turing machine wants to add a string to the list, it sends the string to the printer. Enumerator is a type of Turing machine variant and is equivalent with Turing machine.

Formal definition

An enumerator  can be defined as a 2-tape Turing machine (Multitape Turing machine where ) whose language is . Initially,  receives no input, and all the tapes are blank (i.e., filled with blank symbols). Newly defined symbol  is the delimiter that marks end of an element of . The second tape can be regarded as the printer, strings on it are separated by . The language enumerated by an enumerator  denoted by  is defined as set of the strings on the second tape (the printer).

Equivalence of Enumerator and Turing Machines
A language over a finite alphabet is Turing Recognizable if and only if it can be enumerated by an enumerator. This shows Turing recognizable languages are also recursively enumerable. 

Proof

A Turing Recognizable language can be Enumerated by an Enumerator

Consider a Turing Machine  and the language accepted by it be . Since the set of all possible strings over the input alphabet  i.e. the Kleene Closure  is a countable set, we can enumerate the strings in it as  etc. Then the Enumerator enumerating the language  will follow the steps:

 1 for i = 1,2,3,...
 2 Run  with input strings  for -steps
 3 If any string is accepted, then print it. 

Now the question comes whether every string in the language  will be printed by the Enumerator we constructed. For any string  in the language  the TM  will run finite number of steps(let it be  for ) to accept it. Then in the -th step of the Enumerator  will be printed. Thus the Enumerator will print every string  recognizes but a single string may be printed several times. 

An Enumerable Language is Turing Recognizable  

It's very easy to construct a Turing Machine  that recognizes the enumerable language . We can have two tapes. On one tape we take the input string and on the other tape, we run the enumerator to enumerate the strings in the language one after another. Once a string is printed in the second tape we compare it with the input in the first tape. If it's a match, then we accept the input, otherwise we continue. Note that if the string is not in the language, the turing machine will never halt, thus rejecting the string.

References 

 

Computability theory
Theory of computation
Hennion two-seater. The Hennion was a two-seat French training and touring aircraft, completed just before World War II began. It was flown again post-war and later fitted with a new engine; it survived into the early 1960s.

Design and development

Emile Hennion was the chief pilot at the Casablanca Aero Club in the 1930s. Just before the outbreak of World War II he designed, built and flew a side-by-side seat two seat aircraft, powered by a Train 4A 01 inverted four cylinder air-cooled engine which produced only . His goals were safety in the hands of a beginner, economy, comfort and true touring ability. The first two features made it of some interest as an ab initio trainer after France had gone to war.

In this pre-war form it was known as the Hennion 01. It was a low wing, cantilever monoplane, its wings straight tapered with blunt tips and of quite high aspect ratio (10). The wings were built around a single spar and fabric covered, though the ailerons were plywood skinned.

The fuselage was flat sided and ply skinned, except behind the cockpit where rounded, raised decking was fabric covered.  The Hennion's cockpit was fully enclosed under a two piece canopy with a sliding rear component. Its two seats were equipped with dual controls. Behind them there were luggage and light baggage/chart spaces, respectively  and . The inverted Train engine in the nose drove a two blade propeller and its fuel tank held .  At the rear the vertical tail was tall, with an unbalanced rudder which reached down to the keel and a fuselage mounted tailplane ahead of it.  The Hennion had a tail wheel undercarriage with a track of , its spatted main wheels on vertical, streamlined legs.
The Hennion 01 flew for the first time on 28 September 1939 at Casablanca. Despite the low power, it had a maximum speed of  and cruised at . Cruising, it used about  per hour, giving it a range around . Landing speed was .

The Hennion 01 survived the war and was flown again in 1949, now on the French civil register as F-WFOY. After a period of disuse, it was re-engined in 1956 with a  Continental A65 air-cooled flat-four in a revised nose and redesignated the Hennion II. The extra power gave a useful increase in speed despite an increase in empty weight of about 17%. On 4 February 1962 it was destroyed at Meknes.

Variants
Hennion 01 pre-war version with Train engine
Hennion II 1956 revision with a more powerful Continental engine

Specifications (Hennion II)

References

1930s French sport aircraft
Low-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1939
Orione-class torpedo boat. The Orione class  was a class of four sea-going steam-powered torpedo boats of the Italian Regia Marina (Royal Navy) built by the Odero shipyard of Sestri Ponente from 1905 to 1907. They served in the Italo-Turkish War and the First World War.

Construction and design
On 31 March 1905, four torpedo boats were laid down at the Italian shipbuilder Odero's Sestri Ponente, Genoa shipyard. They were  long between perpendiculars and  overall, with a beam of  and a draught of . Two coal-fired Blechynden boilers fed steam to two sets of triple expansion steam engines rated at , giving a design speed of . Range was  at  and  at . Displacement was . They were fitted with a slightly unusual clipper bow (a bow that curves forward as it rises from the water) and two closely spaced funnels.

Armament was the same as the  and es, with three  torpedo tubes and three 47 mm guns. Crew was three officers and 35 men.

Service
The four ships of the class were completed from February 1907 to April 1908. Although the ships reached speeds of up to  during sea trials, they were less seaworthy than the ships of the Pegaso class. Olimpia and Orfeo were deployed in relief efforts following the 1908 Messina earthquake that devastated Sicily and Calabria on 28 December 1908. Orione collided with the old coastal torpedo boat 128 S in April 1911.  All four ships of the class were active during the Italo-Turkish War, serving in Libyan waters and in the Dodecanese.

During the First World War, the class formed the 1st Torpedo Boat Division, carrying out escort operations in Libyan waters, and between North Africa and Italy. Their armament was modified during the war, with the 47 mm guns replaced by two 76 mm guns and one of the torpedo tubes removed. Orfeo was badly damaged in a collision with the merchant ship Calabria on 10 December 1917, but was repaired. They were disposed of between 1920 and 1923.

Ships

Notes

Citations

References

External links
 Orione-class torpedo Marina Militare website

Torpedo boats of the Regia Marina
World War I naval ships of Italy
Phoenix Industries. Phoenix Industries, Inc. was an American aircraft manufacturer based in Southampton, New Jersey. The company specialized in the design and manufacture of powered parachutes and paramotors in the form of ready-to-fly aircraft in the US FAR 103 Ultralight Vehicles category.

The company produced a powered paraglider, the Phoenix Industries B1Z ParaFlyer of which ten had been sold by 2000, and three powered parachute designs, the Phoenix Industries CV1 ParaFlyer, Phoenix Industries TZ-1 ParaFlyer and the Phoenix Industries Sport. A total of 15 CV1 ParaFlyers and 16 Sports had been sold by 2005. All designs were single-seaters.

The company seems to have been established c. 1997 and gone out of business about 2005.

Aircraft

References

External links

Former location of company website
Company website archives on Archive.org

Defunct aircraft manufacturers of the United States
Ultralight aircraft
Powered parachutes
Paramotors
TEDOM C 12. TEDOM C 12 is a low-floor urban bus produced from 2006 to 2012 by the now defunct bus manufacturing division of the company TEDOM from the Czech Republic. The company ceased bus production in 2012.

Construction features 
Structurally model C 12 does not differ much from the previous bus TEDOM Kronos 123. It is an urban low-floor bus (floor height 340 mm above the ground). Frame chassis is welded thin-walled hollow sections of stainless steel. The cladding is formed from aluminum sheet faces the vehicle and the roof is made of fiberglass.

The manufacturer collaborated with the bus maker company SOR, giving them special tiles for interior and exterior of the vehicle. The interior is insulated by mats with aluminum foil. Toughened glass windows are glued to the body. Troy double doors on the right-side panel are electro controlled. Engine with automatic transmission are placed vertically in the so-called "Chimney" in the right rear corner of the bus. Rear drive axle may be Voith or ZF and front axle is solid (Voith, ZF or LAF). Composite cylinders for CNG (each with a capacity of 320 liters), which are for the gas versions TEDOM C 12 G placed on the roof of the car, the bus can drive 450 km (3 bottles) or 650 km (4 bottles). Fuel tank with diesel version of the C 12 D has a volume of 250 L.

Production and operation 
Model C 12 was created by modifying the structure of the previous type TEDOM Kronos 123 in late 2006 and 2007. During 2007 was produced a total of 23 buses C 12, almost exclusively in the gas version (21 × C 12 G, 2 × C 12 D). 19 gas buses were delivered to Košice, local transport company has become the largest operator of TEDOM buses on the world. One bus in the gas version was delivered to Sofia, Bulgaria. Two diesel buses C 12 D were purchased by Slovak carrier SAD Prešov.

At the Brno AUTOTEC 2008 the model C 12 with a slightly modified front and rear face was introduced .

Production in 2008 included a total of 36 C 12 buses, of which 31 were powered by compressed natural gas and five diesels. Eight cars bought Sofia's public transport company, the company Burgasbus 10 from Burgas, seven Transport Company of Liberec, three cars are leased conveying the company Bratislava (DPB), the remaining gas buses are owned by the manufacturer. Cars with diesel engines purchased SAD Prešov (2 buses) and SAD Lučenec (3 buses)

In 2009, among other buses were manufactured for TRADO MAD Třebíč (3 buses) transport company in Varna (10 buses) and rent for DPB (17 pc).

See also 

 List of buses

References

Buses of the Czech Republic
Buses manufactured by TEDOM
TEDOM C 18. TEDOM C 18 is a prototype of a full low-floor single-decker articulated bus produced by the now defunct bus manufacturing division of the company TEDOM from the Czech Republic in 2010.

Construction features 
This TEDOM C 18 is a prototype of a full low-floor single-decker articulated bus. Engine and automatic transmission are located in the left rear corner of the bus. Inside the bus are used plastic seats for the seating arrangement. Only the rear C axle is propulsed and it is fully low-floor from the inside.

Production and operation 
Only one prototype was made in 2010. It has operated since 2012 in Ústí nad Labem, however, other orders were cancelled as TEDOM closed and folded.

References

External links

 List of buses

Articulated buses
Low-floor buses
Tri-axle buses
Vehicles introduced in 2010
Buses of the Czech Republic
Buses manufactured by TEDOM
Phoenix Industries CV1 ParaFlyer. The Phoenix Industries CV1 ParaFlyer is an American powered parachute that was designed and produced by Phoenix Industries of Southampton, New Jersey. Now out of production, when it was available the aircraft was supplied as a complete ready-to-fly-aircraft.

Design and development
Developed as a version of the Phoenix Industries B1Z ParaFlyer, the CV1 ParaFlyer was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category's maximum empty weight of . The aircraft has a standard empty weight of . It features a parachute-style wing that was available in two sizes, single-place accommodation, tricycle landing gear and a single  Zenoah G-25 engine in pusher configuration.

The CV1 ParaFlyer carriage is built from metal tubing. In flight steering is accomplished via handles that actuate the canopy brakes, creating roll and yaw. On the ground the aircraft has nosewheel steering.

The standard day, sea level, no wind, take off with a  engine is  and the landing roll is .

The aircraft can be folded down small enough to fit into the trunk of some cars or to be carried on a specially-designed bumper carrier.

Specifications (CV1 ParaFlyer)

References

1990s United States ultralight aircraft
Single-engined pusher aircraft
Powered parachutes
Phoenix Industries aircraft
Phoenix Industries Sport. The Phoenix Industries Sport is an American powered parachute that was designed and produced by Phoenix Industries of Southampton, New Jersey. Now out of production, when it was available the aircraft was supplied as in the form of plans for amateur construction. In addition to the plans the company also supplied materials kits and canopies.

Design and development
The Sport was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category's maximum empty weight of . The aircraft has a standard empty weight of . It features a parachute-style wing that was available in a range of sizes from , single-place accommodation and tricycle landing gear. The aircraft can accept engines of  and the recommended engine is the twin-cylinder  Zenoah G-50 engine, which is installed in pusher configuration.

The Sport carriage is built from metal tubing. In flight steering is accomplished via foot levers that actuate the canopy brakes, creating roll and yaw.

The standard day, sea level, no wind, take off with a  engine is  and the landing roll is .

The manufacturer estimated the construction time from the plans as 150 hours.

Specifications (Sport)

References

1990s United States ultralight aircraft
Single-engined pusher aircraft
Powered parachutes
Homebuilt aircraft
Phoenix Industries aircraft
Slicing Petri nets. Petri net (PN) slicing is a syntactic technique used to reduce a PN model based on a given criterion. Informally, a slicing criterion could be a property for which a PN model is analyzed or is a set of places, transitions, or both. A sliced part constitutes only that part of a PN model that may affect the criteria.

Background
The term slicing was coined by M. Weiser in the context of program debugging. According to Wieser, a program slice is a reduced, executable program that can be obtained from a program P based on the variables of interest and line number by removing statements such that program slicing replicates part of the behavior of the program. The term was later adapted to the context of Petri nets and for other classes of Petri nets such as Algebraic Petri nets.

References

Petri nets
Pulsed field magnet. A pulsed field magnet is a strong electromagnet which is powered by a brief pulse of electric current through its windings rather than a continuous current, producing a brief but strong pulse of magnetic field.  Pulsed field magnets are used in research in fields such as materials science to study the effect of strong magnetic fields, since they can produce stronger fields than continuous magnets.   The maximum field strength that continuously-powered high-field electromagnets can produce is limited by the enormous waste heat generated in the windings by the large currents required.  Therefore by applying brief pulses of current, with time between the pulses to allow the heat to dissipate, stronger currents can be used and thus stronger magnetic fields can be generated.   The magnetic field produced by pulsed field magnets can reach between 50 and 100 T, and lasts several tens of milliseconds.

References

Bernd Ctortecka, High-field NMR in pulsed magnets, Max-Planck Innovation.

Electromagnetic coils
Nuclear magnetic resonance
Asok Kumar Barua. Asok Kumar Barua (1 July 1936 – 30 May 2021) was an Indian condensed matter physicist and the honorary Emeritus Professor of Indian Institute of Engineering Science and Technology, Shibpur, who focused on research in optics and optoelectronics. He was honoured by the Government of India in 2003 with Padma Shri, the fourth highest Indian civilian award.

Biography
Asok Kumar Barua was born on 1 July 1936 in Kolkata in the Indian state of West Bengal. He did his schooling at Hare School and graduated in Physics with honours from the Presidency College, Kolkata. His masters studies were at the Rajabazar Science College, Kolkata University (1956) after which he secured his PhD in 1960 from the Indian Association for the Cultivation of Science (IACS) under the guidance of Professor B. N. Srivastava. After completing his post doctoral research in USA, he started his career in 1964 by joining IACS as a Reader where he became a professor in 1971, a director in 1982 and worked there till 1989.

Barua had done research in optics and optoelectronics and had been credited with the indigenous development of amorphous silicon (a-Si) solar cells and solar modules including production technology and equipment. He was also known to have developed a process for Radar opaque coating of aircraft canopies and windshields. His researches have been documented by way of over 300 scientific papers published in peer reviewed journals of international stature. He had also mentored several students in their doctoral research.

An honorary professor of the Indian Institute of Engineering Science and Technology, Shibpur from 2010-2018, Barua was an elected fellow of the Indian Academy of Sciences, Bangalore and the West Bengal Academy of Science and Technology. He had held the chair of the Research and Development committee of the Ministry of New and Renewable Energy under the Jawaharlal Nehru National Solar Mission on solar photovoltaics. He had been a member of the Task Force on Solar Research Initiatives set up by the Department of Science and Technology. He had served the Asia Pacific Academy of Materials as its member, the Sixth International Photovoltaic Science and Engineering Conference as its chairman, the Indian Physical Society as its president and Birla Industrial and Technological Museum as the chairman of its governing council. He was also associated with Hhv Center For Advanced Photovoltaic Technologies as an additional director.

Barua received the Distinguished Materials Scientist of the Year Award in 2002 from the Materials Research Society of India. The Government of India honoured him in 2003 with the civilian award of Padma Shri. He was also a recipient of the Photovoltaic Science and Engineering Conference Award from the Solar Energy Society of India and ICSC-Materials Science prize of the Materials Research Society of India. 

Barua died from COVID-19 in Kolkata on 30 May 2021, at the age of 84.

See also

 Optics
 Optoelectronics

References

External links
 

1936 births
2021 deaths
Recipients of the Padma Shri in science & engineering
Scientists from Kolkata
Bengali scientists
20th-century Indian physicists
Esbjörn Segelod. Esbjörn Segelod (born 1951) is a Swedish organizational theorist and Professor in Business Administration at the Mälardalen University College, School of Business Society and Engineering. He is best known for his work on "knowledge in the software development process" and "software innovativeness"

Life and work 
Segelod obtained his PhD at the University of Gothenburg in 1986 with the thesis, entitled "Kalkylering och avvikelser : empiriska studier av stora projekt i kommuner och industri" (Capital expenditure planning and planning deviations).

After graduation Segelod started his academic career at the University of Gothenburg. In the late 1980s Segelod moved to the Uppsala University, where he was affiliated with its Företagsekonomiska institutionen (Institute for Business Administration). In the late 1990s Segelod was appointed Professor in Business Administration at the Mälardalen University College

Segelod's research interest have broadened over the years, focussing on topics as "sophisticated methods of capital budgeting" in the 1980s, "corporate control of investments" in the 1990s, to the "software development process" and "software innovativeness" in the new millennium.

Selected publications 
 Segelod, Esbjörn. Capital investment appraisal: towards a contingency theory. Chartwell Bratt, 1991.
 Segelod, Esbjörn. Renewal through internal development. Avebury, 1995.

Articles, a selection:
 Segelod, Esbjörn. "Capital budgeting in a fast-changing world." Long Range Planning 31.4 (1998): 529-541.
 Segelod, Esbjörn. "A comparison of managers’ perceptions of short-termism in Sweden and the US." International Journal of Production Economics 63.3 (2000): 243-254.
 Segelod, Esbjörn, and Gary Jordan. "The use and importance of external sources of knowledge in the software development process." R&D Management 34.3 (2004): 239-252.
 Jordan, Gary, and Esbjörn Segelod. "Software innovativeness: outcomes on project performance, knowledge enhancement, and external linkages." R&D Management 36.2 (2006): 127-142.
 Segelod, Esbjörn, and Leif Carlsson. "The emergence of uniform principles of cost accounting in Sweden 1900–36." Accounting, Business & Financial History 20.3 (2010): 327-363.

References

External links 
 Esbjörn Segelod, Mälardalen University

1951 births
Living people
Swedish business theorists
University of Gothenburg alumni
Academic staff of the Stockholm School of Economics
People from Västra Götaland County
20th-century  Swedish economists
Academic staff of Mälardalen University College
NRE 3GS24C-DE-AU. The NRE 3GS24C is a genset locomotive manufactured by National Railway Equipment Company, Paducah, Kentucky for use in Australia.

History
Five members of the class were built for El Zorro. However, before they had left the United States, El Zorro collapsed.

In May 2013, two were unloaded at Port Kembla as demonstrators.

After being demonstrated, they were stored at Broadmeadow. In December 2014, they were hauled to Islington Railway Workshops and are scheduled to enter service with Bowmans Rail hauling containerised hay trains from Bowmans. The other three remain in store in the United States.  Unit 1203 was sold to Caraminer S.A., a subsidiary of the Central Railway Construction Company (CCFC) of Uruguay, to be used in trackwork trains.  It was shipped in March 2021 from USA.

Summary

References

Railway locomotives introduced in 2013
NRE locomotives
Standard gauge locomotives of Australia
Co-Co locomotives