omniomni/omni-engineering huggingface dataset:
Poul-Henning Kamp. Poul-Henning Kamp () is a Danish computer software developer known for work on various projects including FreeBSD and Varnish. He currently resides in Slagelse, Denmark.

Involvement in the FreeBSD project
Poul-Henning Kamp has been committing to the FreeBSD project for most of its duration. He is responsible for the widely used MD5crypt implementation of the MD5 password hash algorithm,
a vast quantity of systems code including the FreeBSD GEOM storage layer, GBDE cryptographic storage transform, part of the UFS2 file system implementation, FreeBSD Jails, the  implementation of the malloc library call, and the FreeBSD and NTP timecounters code, and the  interface with David Mills.

Varnish cache
He is the lead architect and developer for the open source Varnish cache project, an HTTP accelerator.

Dispute with D-Link

In 2006, Kamp had a dispute with electronics manufacturer D-Link in which he claimed they were committing NTP vandalism by embedding the IP address of his NTP servers in their routers. The dispute was resolved in April 2006.

Other

A post by Kamp on the FreeBSD mailing lists is responsible for the popularization of the term bike shed discussion, and the derived term bikeshedding, to describe Parkinson's law of triviality in open source projects - when the amount of discussion that a subject receives is inversely proportional to its importance. Poul-Henning Kamp is known for his preference of a Beerware license to the GNU General Public License (GPL).

Publications 
Poul-Henning Kamp has published a substantial number of articles over the years in publications like Communications of the ACM and ACM Queue mostly on the topics of computing and time keeping. 
A selection of publications:
 USENIX ATC 1998 FREENIX track, "malloc(3) Revisited"
 USENIX BSDCon 2003, GBDE-GEOM Based Disk Encryption
 USENIX BSDCon 2002, Rethinking /dev and devices in the UNIX kernel
 ACM Queue: Building Systems to be Shared Securely
 ACM Queue: You're doing it wrong
 ACM Queue: A Generation Lost in the Bazaar
 Communications of the ACM 2011: The Most Expensive One-Byte Mistake
 Communications of the ACM 2011: The One-Second War

References

External links

 people.freebsd.org homepage
 phk.freebsd.dk homepage
 Blog in Danish 
 Another blog in Danish
 Resolution of D-Link Dispute
 Varnish cache

1966 births
Living people
Danish computer programmers
Danish computer scientists
Free software programmers
FreeBSD people
Articles containing video clips
People from Slagelse
1889 in film. The following is an overview of the events of 1889 in film, including a list of films released and notable births.

Events

 Eastman Kodak is the first company to begin commercial production of film on a flexible transparent base, celluloid.
 The first moving pictures developed on celluloid film are made in Hyde Park, London by William Friese Greene.
 Wordsworth Donisthorpe invents the Kinesigraph, which photographs a round image on 68 mm film.
 William K. L. Dickson completes his work for Thomas Edison on the Kinetograph cylinder either in this year or 1890. Monkeyshines No. 1 becomes the first film shot on the system.

Films
Leisurely Pedestrians, Open Topped Buses and Hansom Cabs with Trotting Horses (also known as Hyde Park Corner), a lost film and the first moving picture developed on celluloid film, directed by William Friese-Greene
Monkeyshines No. 1 – contradictory sources indicate this was shot either in June 1889 or November 1890.

Births

References

External links
List of 1889 films at IMDb
List of 1889 deaths at IMDb
 List of 1889 births at IMDb

 
Film by year
Articles containing video clips
FFC Cambridge process. The FFC Cambridge process is an electrochemical method for producing Titanium (Ti) from titanium oxide by electrolysis in molten calcium salts.

History
A process for electrochemical production of titanium through the reduction of titanium oxide in a calcium chloride solution was first described in a 1904 German patent, and in 1954  was awarded to Carl Marcus Olson for the production of metals like titanium by reduction of the metal oxide by a molten salt reducing agent in a specific gravity apparatus.

The FFC Cambridge process was developed by George Chen, Derek Fray, and Thomas Farthing between 1996 and 1997 at the University of Cambridge. (The name FFC derives from the first letters of the last names of the inventors).  The intellectual property relating to the technology has been acquired by Metalysis, (Sheffield, UK).

Process
The process typically takes place between 900 and 1100 °C, with an anode (typically carbon) and a cathode (the oxide being reduced) in a solution of molten CaCl2. Depending on the nature of the oxide it will exist at a particular potential relative to the anode, which is dependent on the quantity of CaO present in CaCl2.

Cathode reaction mechanism

The electrocalciothermic reduction mechanism may be represented by the following sequence of reactions, where "M" represents a metal to be reduced (typically titanium).

 (1)    

When this reaction takes place on its own, it is referred to as the "calciothermic reduction" (or, more generally, an example of metallothermic reduction).  For example, if the cathode was primarily made from TiO then calciothermic reduction would appear as:

 

Whilst the cathode reaction can be written as above it is in fact a gradual removal of oxygen from the oxide. For example, it has been shown that TiO2 does not simply reduce to Ti. It, in fact, reduces through the lower oxides (Ti3O5, Ti2O3, TiO etc.) to Ti.

The calcium oxide produced is then electrolyzed:

 (2a)   

 (2b)   

and

 (2c)   

Reaction (2b) describes the production of Ca metal from Ca2+ ions within the salt, at the cathode. The Ca would then proceed to reduce the cathode.

The net result of reactions (1) and (2) is simply the reduction of the oxide into metal plus oxygen:

 (3)

Anode reaction mechanism
The use of molten CaCl2 is important because this molten salt can dissolve and transport the "O2−" ions to the anode to be discharged. The anode reaction depends on the material of the anode. Depending on the system it is possible to produce either CO or CO2 or a mixture at the carbon anode:

However, if an inert anode is used, such as that of high density SnO2, the discharge of the O2− ions leads to the evolution of oxygen gas. However the use of an inert anode has disadvantages. Firstly, when the concentration of CaO is low, Cl2 evolution at the anode becomes more favourable. In addition, when compared to a carbon anode, more energy is required to achieve the same reduced phase at the cathode. Inert anodes suffer from stability issues.

References

Further reading

External links
YouTube video:Metalysis FFC process
Metalysis Ltd. website

Chemical processes
Electrochemistry
Titanium processes
Propliner. A propliner is a large, propeller-driven airliner. Typically, the term is used for piston engine airliners that flew before the large scale advent of airliners of the jet age. With the notable exception of the de Havilland Albatross and Fokker F-10 of the late 1920s to 1930s, which were largely fabricated of wood, propliners generally featured all-metal wings and structural members, totally or partially retractable landing gear, and two, three, or four engines. A few might deviate from these characteristics with fixed landing gear, such as the Albatross, Fokker 110, and Lockheed Vega.

The first all metal passenger service propliner was the Handley Page Type W in the 1920s. Then the Boeing 247 made its first flight in 1933, with the Douglas DC-1 and Douglas DC-2 closely following in response. The most successful is the Douglas DC-3, which was produced in the thousands, and is still in widespread use; while the Dewoitine D.338 and SNCASE SE.161 Languedoc were developed in France and Germany produced the Focke-Wulf Fw 200 Condor and Junkers Ju 90. In Japan a license-built version of the Douglas DC-3 was developed as the Nakajima L2D and the smaller Mitsubishi MC-20 was locally developed. In the Netherlands Fokker, previously one of the leading manufacturers of airliners before the Boeing 247 appeared, became the European sales agent for Douglas DC-2s and DC-3s. Most British-built aircraft of the period were less advanced, such as the Avro 642 Eighteen and de Havilland Express; one exception was the Armstrong Whitworth Ensign. Other American-designed propliners included the Douglas DC-4, Douglas DC-5 and Martin 2-0-2. None of these models featured cabin pressurization.

With the earlier introduction of the Boeing 307 Stratoliner and the experimental Douglas DC-4E, a second generation of propliners emerged. These technologically more modern aircraft featured cabin pressurization systems allowing greater comfort by allowing aircraft to fly higher and above much of the lower altitude weather, although it was not until the Lockheed Constellation, followed by the Douglas DC-6 and Douglas DC-7, that this design advance became common.

By the 1950s the traveling public were increasingly finding themselves being transported upon long range pressurized propliners such as the Boeing 377 Stratocruiser, Lockheed L-1049 Super Constellation and Lockheed L-1649 Starliner, or shorter ranged twin engined Martin 4-0-4 and Convair CV-240, CV-340 and CV-440 aircraft. British propliners included the Airspeed Ambassador, Vickers Viking and Handley Page Hermes, while the Canadair North Star (a development of the Douglas DC-4) was produced in Canada. The Breguet Deux-Ponts and Hurel-Dubois HD.31 were manufactured in France; and the Soviet Union produced the postwar twin-engined Ilyushin Il-12 and Ilyushin Il-14, both produced in quantity through the 1950s. Finally, the Swedish SAAB Scandia was produced in small numbers.

See also
De Havilland Canada Dash 8
Fokker 50
Tupolev Tu-114

External links
Descriptions and photos of U.S-built propliners.
Propliner chronology 

Airliners
Iterative closest point. Iterative closest point (ICP) is a point cloud registration algorithm employed to minimize the difference between two clouds of points. ICP is often used to reconstruct 2D or 3D surfaces from different scans, to localize robots and achieve optimal path planning (especially when wheel odometry is unreliable due to slippery terrain), to co-register bone models, etc.

Overview
The Iterative Closest Point algorithm keeps one point cloud, the reference or target, fixed, while transforming the other, the source, to best match the reference. The transformation (combination of translation and rotation) is iteratively estimated in order to minimize an error metric, typically the sum of squared differences between the coordinates of the matched pairs. ICP is one of the widely used algorithms in aligning three dimensional models given an initial guess of the rigid transformation required.
The ICP algorithm was first introduced by Chen and Medioni, and Besl and McKay.

Inputs: reference and source point clouds, initial estimation of the transformation to align the source to the reference (optional), criteria for stopping the iterations.

Output: refined transformation.

Essentially, the algorithm steps are:

 For each point (from the whole set of vertices usually referred to as dense or a selection of pairs of vertices from each model) in the source point cloud, match the closest point in the reference point cloud (or a selected set).
 Estimate the combination of rotation and translation using a root mean square point-to-point distance metric minimization technique which will best align each source point to its match found in the previous step. This step may also involve weighting points and rejecting outliers prior to alignment.
 Transform the source points using the obtained transformation.
 Iterate (re-associate the points, and so on).

Zhang  proposes a modified k-d tree algorithm for efficient closest point computation. In this work a statistical method based on the distance distribution is used to deal with outliers, occlusion, appearance, and disappearance, which enables subset-subset matching.

There exist many ICP variants, from which point-to-point and point-to-plane are the most popular. The latter usually performs better in structured environments.

Implementations
 MeshLab an open source mesh processing tool that includes a GNU General Public License implementation of the ICP algorithm.
 CloudCompare an open source point and model processing tool that includes an implementation of the ICP algorithm. Released under the GNU General Public License.
 PCL (Point Cloud Library) is an open-source framework for n-dimensional point clouds and 3D geometry processing. It includes several variants of the ICP algorithm.
 Open source C++ implementations of the ICP algorithm are available in VTK, ITK and Open3D libraries.
 libpointmatcher is an implementation of point-to-point and point-to-plane ICP released under a BSD license.
 simpleICP is an implementation of a rather simple version of the ICP algorithm in various languages.

See also 
 Normal distributions transform

References

Geometry in computer vision
Robot navigation
Heat-affected zone. In fusion welding, the heat-affected zone (HAZ) is the area of base material, either a metal or a thermoplastic, which is not melted but has had its microstructure and properties altered by welding or heat intensive cutting operations. The heat from the welding process and subsequent re-cooling causes this change from the weld interface to the termination of the sensitizing temperature in the base metal. The extent and magnitude of property change depends primarily on the base material, the weld filler metal, and the amount and concentration of heat input by the welding process.

The thermal diffusivity of the base material plays a large role—if the diffusivity is high, the material cooling rate is high and the HAZ is relatively small. Alternatively, a low diffusivity leads to slower cooling and a larger HAZ. The amount of heat input during the welding process also plays an important role as well, as processes like oxyfuel welding use high heat input and increase the size of the HAZ.  Processes like laser beam welding and electron beam welding give a highly concentrated, limited amount of heat, resulting in a small HAZ. Arc welding falls between these two extremes, with the individual processes varying somewhat in heat input. To calculate the heat input for arc welding procedures, the following formula is used:

where  = heat input (kJ/mm),  = voltage (V),  = current (A), and  = welding speed (mm/min).  The efficiency is dependent on the welding process used, with gas tungsten arc welding having a value of 0.6, shielded metal arc welding and gas metal arc welding having a value of 0.8, and submerged arc welding 1.0.

References

Weman, Klas (2003).  Welding processes handbook.  New York: CRC Press LLC. .

Welding
Charles Goldfarb. Charles F. Goldfarb, (born November 26, 1939) is known as the father of Standard Generalized Markup Language (SGML) and grandfather of HTML and the World Wide Web, also referred to as WWW, W3, or the Web. He co-invented the concept of markup languages.

In 1969 Charles Goldfarb, leading a small team at IBM, developed the first markup language, called Generalized Markup Language, or GML. Goldfarb coined the term GML, an initialism for the three researchers, Charles Goldfarb, Ed Mosher and Ray Lorie, who worked on the project.

In 1974, Goldfarb designed SGML and subsequently wrote the first SGML parser, ARC-SGML. SGML facilitates the sharing of machine readable documents for large projects. SGML was used by the military and aerospace, and industrial publishing. Goldfarb continued working to turn SGML into the ISO 8879 standard, and served as its editor in the standardization committee.

Goldfarb held a J.D. from Harvard Law School. After working at IBM's Almaden Research Center, he was an independent consultant based in Belmont, California.

Selected publications
The SGML Handbook, Oxford University Press (1991), 
SGML Buyer's Guide, Prentice Hall (1998), 
XML Handbook, Prentice Hall (1998),

References

External links
Charles F. Goldfarb's SGML Homepage
A Conversation with Charles F. Goldfarb
XML Opportunities Knocking (Interview Part 2)

Living people
1939 births
Harvard Law School alumni
IBM employees
Markup languages
People from Belmont, California
SGML
Foamcore. Foamcore, foam board, or paper-faced foam board is a lightweight and easily cut material used for mounting of photographic prints, as backing for picture framing, for making scale models, and in painting.  It consists of a board of polystyrene foam clad with an outer facing of paper on either side, typically white clay-coated paper or brown kraft paper.

History
The original white foamcore board was made in  thicknesses for the graphic arts industry by Monsanto Company under the trade name "Fome-Cor®" starting in 1961.

Construction, variants and composition

The surface of the regular board, like many other types of paper, is slightly acidic. However, for modern archival picture framing and art mounting purposes it can be produced in a neutral, acid-free version with a buffered surface paper, in a wide range of sizes and thicknesses.

Foam-cored materials are also now available with a cladding of solid (non-foamed) polystyrene and other rigid plastic sheeting, some with a textured finish.

Foamcore does not adhere well to some glues, such as superglue, and certain types of paint.  The foam tends to melt away and dissolve.  Some glue works well in casual settings, however, the water in the glue can warp the fibers in the outer layers. Best results are typically obtained from higher-end spray adhesives. A hot glue gun can be used as a substitute, although the high viscosity of hot glues can affect finished projects in the form of board warping, bubbles, or other unsightly blemishes.

Self-adhesive foam boards, intended for art and document mounting are also available, though these can be very tricky to use properly; this is because the glue sets very fast. It is considered cheaper to buy plain foam board and use re-positionable spray mount adhesive.

Specialty constructions have been developed for engineering uses.

Uses

Foamcore is commonly used to produce architectural models, prototype small objects and to produce patterns for casting. Scenery for scale model displays, dioramas, and computer games are often produced by hobbyists from foamcore.

Foamcore is also often used by photographers as a reflector to bounce light, in the design industry to mount presentations of new products, and in picture framing as a backing material; the latter use includes some archival picture framing methods, which utilize the acid-free versions of the material.  Another use is with aero-modellers for building radio-controlled aircraft.

Researchers at the University of Manchester created their Giant Foamboard Quadcopter (GFQ) claimed to be the largest possible Civil Aviation Authority licensed drone with an  all-up weight (UWT) just below the maximum of  25 Kg (c.55 lbs).

See also
Corrugated fiberboard (Cardboard)
Closed-cell PVC foamboard
Arts and crafts
Mat (picture framing)

References

Visual arts materials
Composite materials
Hyetograph. A hyetograph is a graphical representation of the distribution of rainfall intensity over time. For instance, in the 24-hour rainfall distributions as developed by the Soil Conservation Service (now the NRCS or National Resources Conservation Service), rainfall intensity progressively increases until it reaches a maximum and then gradually decreases. Where this maximum occurs and how fast the maximum is reached is what differentiates one distribution from another. One important aspect to understand is that the distributions are for design storms, not necessarily actual storms. In other words, a real storm may not behave in this same fashion. The maximum intensity may not be reached as uniformly as shown in the SCS hyetographs.

See also
Voronoi diagram - a method adaptable for calculating the average precipitation over an area

External links
 Precipitation Maps for USA

Hydrology
Robert Watson (computer scientist). Robert Nicholas Maxwell Watson (born 3 May 1977) is a FreeBSD developer, and founder of the TrustedBSD Project. He is currently employed as a Professor of Systems, Security, and Architecture in the Security Research Group at the University of Cambridge Computer Laboratory.

Education
Watson graduated in computer science from Carnegie Mellon University and has attained a PhD from University of Cambridge.  As well as Cambridge, he has worked at the National Institutes of Health, Carnegie Mellon University, Trusted Information Systems, Network Associates, McAfee, and SPARTA. He obtained a PhD in computer security from the University of Cambridge Computer Laboratory, supervised by Ross Anderson and sponsored by Google.

Research
Watson's work has been supported by DARPA, Apple Computer, the Navy, and other US government agencies. His main research interests are network security and operating system security. His main open source software contributions include his work in developing the multi-threaded and multi-processor FreeBSD network stack, the TrustedBSD project, and OpenBSM. His writing has been featured in forums such as ACM's Queue Magazine, the USENIX Annual Technical Conference, BSDCon, and a Slashdot interview. He was also a FreeBSD Core Team member from 2000 to 2012. Watson is coauthor of the standard textbook The Design and Implementation of the FreeBSD Operating System (2nd ed., 2015) by Marshall Kirk McKusick.

References

Free software programmers
Living people
FreeBSD people
People from Harrow, London
1977 births
British computer scientists
Members of the University of Cambridge Computer Laboratory
Fellows of St John's College, Cambridge