omniomni/omni-engineering huggingface dataset:
Spartan C4. The Spartan C4 was an American four-seat cabin monoplane designed and built by the Spartan Aircraft Company.

Design and development
The first model was the C4-225 a high-wing braced monoplane powered by a  Wright J-6 radial engine. Only five C4-235 aircraft were built and they were followed by one C4-300 with a  Wright R-975 radial engine, and the C4-301 with a  Pratt & Whitney Wasp Junior.

Variants
C4-225
Production aircraft powered by a  Wright J-6 radial engine, five built.
C4-300
Variant with a  Wright R-975 radial engine, one built.
C4-301
Variant with a  Pratt & Whitney Wasp Junior  radial engine, one built.

Specifications (C4-225)

See also

References

Notes

Bibliography
 
 

1930s United States civil utility aircraft
Spartan Aircraft Company aircraft
High-wing aircraft
Aircraft first flown in 1930
Aircraft with fixed conventional landing gear
Gustav Wittfeld. Gustav Wittfeld (27 October 1855 – 24 September 1923) was a German engineer.

Life 
Gustav Wittfeld was born in Aachen, Germany, on 27 October 1855. After attending state school he studied at the polytechnic in Aachen from 1874 to 1878. Following that the young engineer joined the Prussian state railways. He spent his early years in the railway divisions of Bromberg, Cassel, Frankfurt am Main, Cologne and Berlin.

He was promoted to government master builder (Regierungsbaumeister) in 1884 and was involved in the construction of Frankfurt (Main) Hauptbahnhof. After transferring to the Berlin railway division in 1891 he again joined the department for the construction and procurement of locomotives within the Prussian state railways. He played a major part in the committee set up for Prussian locomotive construction standards.

In 1902, at the instigation of Wittfeld, the Prussian railway administration and AEG began trials with single-phase alternating current for use as a source of traction. The testing lasted until 1906 and took place on the 4.1 km long suburban route from Niederschöneweide to Spindlersfeld (near Berlin) using 6 kV 25 Hz AC. This technology was used initially when the Hamburg-Altona City and Suburban Railway was electrified, a venture in which Wittfeld was also involved. Wittfeld was the first to recorgnise the importance of single-phase AC for electric traction and was a driving force behind the electrification of the first standard gauge railway in Germany from Dessau to Bitterfeld opened on 1 April 1911.

In 1904, with Wittfeld's involvement, two 2'B2'n3v - experimental steam locomotives emerged: "Altona 561 and Altona 562" with streamlining and a cab at the front. After these proved a failure due to the cost of the trial, Gustav Wittfeld turned increasingly to electric traction and designed the Prussian Class ES, EP and EG electric locomotives. Even today the design of the Class AT 3 accumulator cars (later DRG Class ETA 178) is associated with the name of Wittfeld. They were still in service until the early 1960s. These designs and his perseverance earned Wittfeld the reputation of being a trailblazer in the field of electric train transportation.

In 1917 he became an honorary Doctor of Engineering at the TH Charlottenburg for his work on the electrification of the railways. In 1918 he was promoted to Wirklicher Geheimer Oberbaurat and retired in  1920. As his successor he appointed  Wilhelm Wechmann, later to become Chief Electrical Engineer of the Deutsche Reichsbahn.

On 24 September 1923, plagued from ill-health, Wittfeld committed suicide.

See also
 List of railway pioneers

References

Sources 
 :de:Gustav Wittfeld
 

1855 births
1923 deaths
German railway pioneers
German railway mechanical engineers
Engineers from the German Empire
Engineers from Aachen
1923 suicides
Suicides in Germany
Non-contact ultrasound. Non-contact ultrasound (NCU) is a method of non-destructive testing where ultrasound is generated and used to test materials without the generating sensor making direct or indirect contact with the test material or test subject. Historically this has been difficult to do, as a typical transducer is very inefficient in air. Therefore, most conventional ultrasound methods require the use of some type of acoustic coupling medium in order to efficiently transmit the energy from the sensor to the test material. Couplant materials can range from gels or jets of water to direct solder bonds. However, in non-contact ultrasound, ambient air is the only acoustic coupling medium.

An electromagnetic acoustic transducer (EMAT), is a type of non-contact ultrasound that generates an ultrasonic pulse which reflects off the sample and induces an electric current in the receiver. This is interpreted by software and provides clues about the internal structure of the sample such as cracks or faults.

Research is continuing to improve traditional transducers by applying different plastics, elastomers, and other materials. The sensitivity of these devices continues to improve; a newly developed piezoelectric transducer can produce frequencies in the MHz that can easily propagate through even high acoustic impedance materials such as steel and dense ceramics.

Non-contact ultrasound allows some materials to be inspected which otherwise can't be inspected due to fear of contamination from couplants or water. In general non-contact ultrasound would facilitate testing of materials or components that are continuously rolled on a production line, in extremely hot environments, coated, oxidized, or otherwise difficult to physically contact. Methods for potential medical use are also being investigated

Laser ultrasonics is another method of non-contact ultrasound.

References 

Nondestructive testing
Gloster TSR.38. The Gloster TSR.38 was a single-engined three-seat biplane designed as a naval torpedo/spotter/reconnaissance aircraft in the early 1930s.  It did not reach production and only one was built.

Development
Gloster built what was at first known as the FS.36 (FS standing for fleet spotter) to Air Ministry specification S.9/30 which called for a three-seat torpedo bomber/spotter/reconnaissance aircraft, starting work in late 1930 but proceeding slowly so it did not fly until early April 1932. This aircraft, powered by a 600 hp (450 kW) Rolls-Royce Kestrel IIMS engine was flown to RAF Martlesham Heath for initial testing.  RAF pilots reported good handling at higher speeds but criticised its low speed handling and braking, important parameters for a carrier landing aircraft.  It then returned to Gloster's for modification, partly to meet these criticisms and partly to cover a new specification S.15/33, a melding of the early specification with M.1/30.  Re-engined with a Rolls-Royce Goshawk VIII of 690 hp (515 kW), and with modified wings of greater area the aircraft emerged in mid-1933 as the TSR.38, TSR standing for torpedo/spotter/reconnaissance.

The TSR.38 was a fabric covered all metal machine with steel sparred wings with duralumin and steel ribs. It was a single bay biplane with staggered wings of almost equal span and sharp, 10° sweepback.  The airfoils were thick, the lower thicker and the upper wings carried leading edge automatic slots for low speed control.  The wings could be folded from the centre section for carrier stowage. The lower wing centre section had anhedral to allow a shorter undercarriage and also carried a pair of underwing radiators.  The undercarriage was of the fixed, split axle type required for torpedo launches, with torpedo crutches between the legs and there was a small, spatted tailwheel.  For carrier landing there was a hinged arrestor hook ending just in front of the tailwheel. The three crew sat in separate open cockpits, the pilot in front under a cut-out in the upper wing trailing edge, his navigator behind him and furthest aft the gunner with a Lewis gun on a Scarff ring.  The fin was large and rounded with a generous rudder, a little like that of the later Gladiator, with the tailplane braced from above to the fin.

Operational history
After flight trials at Gloster's the TSR.38 went to RAF Gosport where it made dummy carrier landing before joining  in August 1934 for real naval tests.  It then returned to Martlesham for a thorough evaluation.  However, its rather dilatory development now caught up with it in the form  of a superior, later private venture from Fairey, which was to become the famous Fairey Swordfish and further work on the TSR.38 was ended.

A design for pure reconnaissance variant was submitted to the Royal Australian Navy in 1931 but was not successful.

Specifications (TSR.38, reconnaissance configuration)

References

Notes

Bibliography
 

1930s British aircraft
TSR.38
Aircraft first flown in 1932
Biplanes
Single-engined tractor aircraft
Carrier-based aircraft
Aircraft with fixed conventional landing gear
Hugh Franklin Waters. Hugh Franklin Waters (July 20, 1932 – April 16, 2002) was a United States district judge of the United States District Court for the Western District of Arkansas.

Education and career

Born in Hackett, Arkansas, Waters received a Bachelor of Science in agricultural engineering from the University of Arkansas in 1955. He was in the United States Navy as a Lieutenant (JG) from 1955 to 1958. He was an agricultural engineer at the Ralston Purina Company in St. Louis, Missouri from 1958 to 1964. He received a Bachelor of Laws from Saint Louis University School of Law in 1964. He was the company attorney at Ralston Purina from 1964 to 1966. He was in private practice of law in Springdale, Arkansas from 1967 to 1981. He was a part-time instructor at the University of Arkansas Law School in 1968.

Federal judicial service

Waters was nominated by President Ronald Reagan on August 28, 1981, to a seat on the United States District Court for the Western District of Arkansas vacated by Judge Paul X. Williams. He was confirmed by the United States Senate on October 21, 1981, and received his commission on October 26, 1981. He served as Chief Judge from 1981 to 1997. He assumed senior status on August 1, 1997.  His service was terminated on April 16, 2002, due to his death in Fayetteville, Arkansas.

References

Sources
 

Judges of the United States District Court for the Western District of Arkansas
Agricultural engineers
1932 births
2002 deaths
Saint Louis University School of Law alumni
University of Arkansas alumni
Ralston Purina
United States Navy officers
People from Springdale, Arkansas
United States district court judges appointed by Ronald Reagan
David Stahl. David Stahl may refer to:

 David Stahl (conductor) (1949–2010), American conductor
 David Henry Stahl (1920–1970), American attorney and federal judge
 David Stahl (biologist), American scientist and professor of environmental engineering
 David Stahl, mayor of East Brunswick, New Jersey
 David Stahl (Businessman) (1986–Present), American businessman, entrepreneur, hedge fund manager
Genius (mathematics software). Genius  (also known as the Genius Math Tool) is a free open-source numerical computing environment and programming language, similar in some aspects to MATLAB, GNU Octave, Mathematica and Maple.  Genius is aimed at mathematical experimentation rather than computationally intensive tasks.  It is also very useful as just a calculator.  The programming language is called GEL and aims to have a mathematically friendly syntax.  The software comes with a command-line interface and a GUI, which uses the GTK+ libraries.  The graphical version supports both 2D and 3D plotting.  The graphical version includes a set of tutorials originally aimed at in class demonstrations.

History 

Genius was the original calculator for the GNOME project started in 1997, but was split into a separate project soon after the 0.13 release of GNOME in 1998.  Because of this ancestry, it was also known as Genius Calculator or GNOME Genius.  There was an attempt to merge Genius and the Dr. Geo interactive geometry software, but this merge never materialized.  Version 1.0 was released in 2007 almost 10 years after the initial release.

Example GEL source code 

Here is a sample definition of a function calculating the factorial recursively
function f(x) = (
  if x <= 1 then
    1
  else
    (f(x-1)*x)
)
GEL contains primitives for writing the product iteratively and hence we can get the following iterative
version
function f(x) = prod k=1 to x do k

See also 

 Comparison of numerical analysis software

Notes and references 

Array programming languages
Free educational software
Free mathematics software
Free software programmed in C
Numerical analysis software for Linux
Numerical analysis software for macOS
Numerical programming languages
Science software that uses GTK
Unix programming tools
Franz Xaver Riepl. Franz Xaver Riepl  (29 November 1790 – 25 April 1857) was a geologist, railway pioneer and metallurgical specialist from the Austrian Empire.

Life
Riepl was born in Graz, Styria where his father worked as a building inspector. He attended the mining college in Schemnitz (present-day Banská Štiavnica, Slovakia) and, back in Graz, worked with the famous geologist Friedrich Mohs (1773–1839) at the Joanneum technical college. From 1816 he was employed at the Fürstenberg iron mines in Nižbor (Nischburg), Bohemia and undertook extended study tours through Saxony, Bavaria, Prussian Silesia, and Moravia.

Between 1819 and 1835 he worked as a professor at the Imperial and Royal Polytechnic Institute in Vienna. During the 1820s, Riepl again made study trips through the Inner Austrian and Illyrian provinces of the Austrian monarchy; it was from him that the initiative came to quarry the Styrian Erzberg using open cast mining. He also assisted the Austrian State Chancellor Prince Klemens von Metternich establishing iron works on his estates in Plasy, Bohemia. With the support of the Olomouc Cardinal Archduke Rudolf of Austria, he also worked as a surveyor at the Friedland (Frýdlant) mines in Moravia. In 1829 he gave the impulse for building the important Witkowitz iron works nearby, where he introduced the English puddling process. 

As early as 1828 Riepl had developed plans for a railway network across the whole Austrian Empire, including the later Southern Railway as well as a railway link from the Kingdom of Galicia via Vienna to the Port of Trieste. In 1830 he presented detailed route diagrams of a railway line running from Vienna to the Witkowitz iron works and further eastwards to the Wieliczka Salt Mine near Kraków. In the following years, he travelled to England several times to study the construction of railway lines. Receiving large funds by Salomon Mayer von Rothschild, his plans were finalised: backed by Chancellor Metternich and the Bohemian "stadtholder" Franz Anton von Kolowrat-Liebsteinsky, Riepl and Rothschild received the commission for the building of the Emperor Ferdinand Northern Railway line (Nordbahn) from Vienna to Bochnia. Construction began in 1937, the line up to Bohumín (Oderberg) in Austrian Silesia was completed in 1847. One year later, a connection to the Prussian Upper Silesian Railway; a transport link to Kraków was provided by the Eastern National Railway from 1856.

Riepl died in Vienna, aged 66. He was buried in the Hinterbrühl cemetery in Lower Austria. In 1904 the street of Rieplstrasse in Vienna's Favoriten district was named after him.

See also 
 List of railway pioneers

Sources 
 :de:Franz Xaver Riepl

External links 
Riepl, Franz X., in Constant von Wurzbach, Biographisches Lexikon des Kaiserthums Oesterreich, 26. Band, Wien 1874,
 
 Prof. Riepl im Kontext der "österr. Eisenbahngeschichte"

1790 births
1847 deaths
Engineers from the Austrian Empire
Engineers from Graz
Academic staff of TU Wien
Scientists from Graz
Multi-simulation coordinator. MUSIC (Multi-Simulation Coordinator) is software developed and released by the INCF and Royal Institute of Technology (KTH) School of Computer Science and Communication in Stockholm, Sweden. MUSIC is designed for interconnecting
large scale neuronal network simulators, either with each other or with other
tools. It allows spike events and continuous time series to be communicated between such applications in a cluster computer. The typical usage cases are connecting models developed for different simulators and connecting a parallel simulator to a post-processing tool.

MUSIC provides a standardized software interface (API) on top of the message-passing interface (MPI) for communication among parallel applications for large-scale computational neuroscience simulations. It enables the transfer of massive amounts of event information and continuous values from one parallel application to another, including those using different data allocation strategies. In the design of the standard interface, care was taken to allow easy adaptation of existing simulators and to permit third-party development and community-sharing of reusable and interoperable software tools for parallel processing. Three simulators currently have MUSIC interfaces: Moose, NEURON and NEST.

The MUSIC software library and its documentation are publicly available through the INCF Software Center.

References 

 INCF website

External links
 MUSIC homepage at INCF Software Center

Computational neuroscience
Simulation software
Cluster computing
Epoch Systems. Epoch Systems Inc., founded in December 1986, was a hardware and software company providing Hierarchical Storage Management (HSM) file servers, and distributed storage management and data backup software. The company was founded by Ken Holberger, Chuck Holland, and Gregory Kenley. Holberger and Holland had worked together as part of the Eagle project described in The Soul of a New Machine. Kenley was a software engineer with expertise in operating systems and storage management. The company began in Marlboro MA and eventually moved to Westborough MA.

Products
The company's first product was the Epoch-1 Infinite Storage Server. The Epoch-1 consisted of custom 68020-based CPU board running a modified version of the BSD 4.2 Unix operating system. The product was released in 1988 and provided 30GB of storage in its base configuration, expandable to 150GB. The server combined optical and magnetic storage and used HSM algorithms to automatically migrate files between the two types of media as required. The base 30GB model sold for $158,000 with one 30GB optical disk library unit and one 760MB magnetic disk drive. By making use of high capacity and comparatively inexpensive (for that time) optical storage the Epoch-1 provided high storage capacity at substantially lower cost than all-magnetic file servers.

Epoch's second product, EpochBackup, included automatic scheduling, online backup and volume management features for Unix-based client workstations from a number of manufacturers, including DEC, IBM, Hewlett Packard, Silicon Graphics and Sun Microsystems.

In late 1990 Epoch released versions of its Renaissance storage management products for Sun, HP, and MIPS Technologies Unix workstations. The system provided HSM services for workstations and servers, automatically migrating least used files to an Epoch-1 server centrally located on the network to free up space when file systems became full. Files were automatically retrieved when accessed. Because of difficulties in implementing this product across many different Unix implementations, Epoch started the Data Management Interfaces Group with the goal of creating a common API for storage management.

Funding
Epoch Systems raised $15.7M of venture capital in three different rounds from several firms including Charles River Ventures,
Matrix Partners, Sigma Partners, TA Associates, Atlas Venture, Sierra Ventures, and Ampersand Ventures. The company was bought by EMC for approximately $140M on August 31, 1993.

References

Sources
Kidder, Tracy (1981). The Soul of a New Machine. Little, Brown and Company. Reprint edition July 1997 by Modern Library. .

Defunct software companies of the United States
Computer storage companies
Defunct computer companies of the United States
Defunct computer hardware companies
Hamcrest. Hamcrest is a framework that assists writing software tests in the Java programming language. It supports creating customized assertion matchers ('Hamcrest' is an anagram of 'matchers'), allowing match rules to be defined declaratively. These matchers have uses in unit testing frameworks such as JUnit and jMock. Hamcrest has been included in JUnit 4 since 2007,
but was omitted from JUnit 5 in 2017.

Hamcrest has been ported to C++, C#, Objective-C, Python, ActionScript 3, PHP, JavaScript, Erlang, R, Rust, Java, PHP, Go, Common Lisp and Swift.

Rationale

"First generation" unit test frameworks provide an 'assert' statement, allowing one to assert during a test that a particular condition must be true. If the condition is false, the test fails. For example:
assert(x == y);

But, in many languages, this syntax fails to produce a sufficiently good error message if 'x' and 'y' are not equal. It would be better if the error message displayed the value of 'x' and 'y'. To solve this problem, "second generation" unit test frameworks provide a family of assertion statements, which produce better error messages. For example,
assert_equal(x, y);
assert_not_equal(x, y);

But this leads to an explosion in the number of assertion macros, as the above set is expanded to support comparisons different from simple equality. So "third generation" unit test frameworks use a library such as Hamcrest to support an 'assert_that' operator that can be combined with 'matcher' objects, leading to syntax like this:
assert_that(x, equal_to(y))
assert_that(x, is_not(equal_to(y)))

The benefit is that there are still fluent error messages when the assertion fails, but with greater extensibility. It is now possible to define operations that take matchers as arguments and return them as results, leading to a grammar that can generate a huge number of possible matcher expressions from a small number of primitive matchers.

These higher-order matcher operations include logical connectives (and, or and not), and operations for iterating over collections. This results in a rich matcher language which allows complex assertions over collections to be written in a declarative style rather than a procedural style.

References

External links
 
 

Java platform software
Unit testing frameworks
Just another Gibbs sampler. Just another Gibbs sampler (JAGS) is a program for simulation from Bayesian hierarchical models using Markov chain Monte Carlo (MCMC), developed by Martyn Plummer. JAGS has been employed for statistical work in many fields, for example ecology, management, and genetics.

JAGS aims for compatibility with WinBUGS/OpenBUGS through the use of a dialect of the same modeling language (informally, BUGS), but it provides no GUI for model building and MCMC sample postprocessing, which must therefore be treated in a separate program (for example calling JAGS from R through a library such as rjags and post-processing MCMC output in R).

The main advantage of JAGS in comparison to the members of the original BUGS family (WinBUGS and OpenBUGS) is its platform independence. It is written in C++, while the BUGS family is written in Component Pascal, a less widely known programming language. In addition, JAGS is already part of many repositories of Linux distributions such as Ubuntu. It can also be compiled as a 64-bit application on 64-bit platforms, thus making all the addressable space available to BUGS models.

JAGS can be used via the command line or run in batch mode through script files. This means that there is no need to redo the settings with every run and that the program can be called and controlled from within another program (e.g. from R via rjags as outlined above).

JAGS is licensed under the GNU General Public License.

See also
 Stan (software)

References

External links
JAGS, SourceForge page
JAGS, FreshPorts page
rjags, R (programming language) Page

Free Bayesian statistics software
Free software programmed in C++