omniomni/omni-engineering huggingface dataset:
Electromechanical modeling. The purpose of electromechanical modeling is to model and simulate an electromechanical system, such that its physical parameters can be examined before the actual system is built. Parameter estimation utilizing different estimation theory coupled with physical experiments and physical realization by doing proper stability criteria evaluation of the overall system is the major objective of electromechanical modeling. Theory driven mathematical model can be used or applied to other system to judge the performance of the joint system as a whole. This is a well known and proven technique for designing large control system for industrial as well as academic multi-disciplinary complex system. This technique is also being employed in MEMS technology recently.

Different types of mathematical modeling

The modeling of purely mechanical systems is mainly based on the Lagrangian which is a function of the generalized coordinates and the associated velocities. If all forces are derivable from a potential, then the time behavior of the dynamical systems is completely determined. For simple mechanical systems, the Lagrangian is defined as the difference of the kinetic energy and the potential energy.

There exists a similar approach for electrical system. By means of the electrical coenergy and well defined power quantities, the equations of motions are uniquely defined. The currents of the inductors and the voltage drops across the capacitors play the role of the generalized coordinates. All constraints, for instance caused by the Kirchhoff laws, are eliminated from the considerations. After that, a suitable transfer function is to be derived from the system parameters which eventually governs the behavior of the system.

In consequence, we have quantities (kinetic and potential energy, generalized forces) which determine the mechanical part and quantities (coenergy, powers) for the description of the electrical part. This offers a combination of the mechanical and electrical parts by means of an energy approach. As a result, an extended Lagrangian format is produced.

See also
Mechatronics
Mechanical–electrical analogies

References 

__notoc__
Electromechanical engineering
Mechanics
Electrodynamics
Microelectronic_and_microelectromechanical_systems
Avolution. Avolution is a global provider of Enterprise Architecture, Enterprise Modeling and Process Modeling software with offices based in Sydney, Singapore, London, Dubai, Washington Metropolitan Area and New Brunswick.  Avolution was spun-out from the University of Technology, Sydney in 2001.

The company's product, ABACUS, is a software package used for Enterprise Architecture (EA), Enterprise Modeling, Process Modeling and Roadmapping and supports over 100 frameworks and notations including TOGAF, ArchiMate, BPMN, UML, UPDM, ITIL, FEAF, Zachman and Frameworx.

The name ABACUS stands for the "Algorithm-Based Analysis, Communication and Understanding of Systems".

See also 
 Enterprise Architecture
 Enterprise Modeling
 Process Modeling
 Project Portfolio Management
 Service-Oriented Architecture

References

External links 
 
 YouTube channel
 The Open Group

Enterprise modelling
Software companies of Australia
Load-loss factor. Load-loss factor (also loss load factor,  LLF, or simply loss factor) is a dimensionless ratio between average and peak values of load loss (loss of electric power between the generator and the consumer in electricity distribution). Since the losses in the wires are proportional to the square of the current (and thus the square of the power), the LLF can be calculated by measuring the square of delivered power over a short interval of time (typically half an hour), calculating an average of these values over a long period (a year), and dividing by the square of the peak power exhibited during the same long period: 

, where

  is the total number of short intervals (there are 8760 hours or 17,520 half-hours in a year);
  is the load experienced during the short interval ;
  is the peak load  within the long interval (typically a year).   

The LLF value naturally depends on the load profile. For electricity utilities, numbers about 0.2-0.3 are typical (cf. 0.22 for Toronto Hydro, 0.33 for New Zealand). Multiple empirical formulae exist that relate the loss factor to the load factor (Dickert et al. in 2009 listed nine).

Similarly, the ratio between the average and the peak current is called form coefficient k or peak responsibility factor k, its typical value is between 0.2 to 0.8 for distribution networks and 0.8 to 0.95 for transmission networks. Coefficient k describes the losses as an additional load carried by the system, and is named loss equivalent load factor in Japan.

See also 
 Line Loss Factor, a regulatory definition of the line loss in UK

References

Sources 
 
 

Electric power conversion
James J. Shuttleworth. James J. Shuttleworth (1937  – 2003) was an American inventor and entrepreneur who founded Shuttleworth, Inc. He was an active business and community leader in Northeastern Indiana.

Education
Shuttleworth was a graduate of Warren High School in 1955. He attended Purdue University and received a Bachelor of Science degree in mechanical engineering in 1960.

Activities after graduation
Shuttleworth returned to his family’s canning and machinery operation. In 1962, he purchased the machinery side of the business and founded the Shuttleworth Machinery Corporation. Serving as engineer, salesman and president, he built the company into a leader in automated material handling systems. The company was renamed Shuttleworth, Inc. in 1974.

Jim learned to fly while still in school and noted that flying played a significant role in growing his company. He restored vintage aircraft, including   a 1943 AT-6G Texan and a P-51 Mustang that was once flown by Robin Olds. Shuttleworth also founded the Wings of Freedom Museum in 1996. This collection now resides at the Hoosier Air Museum.

Death
Jim died while piloting a TF-51 Dual Control Mustang near Wabash, Indiana on February 20, 2003.

Honors
1990: Purdue University Distinguished Engineering Alumnus Award
1991: Outstanding Mechanical Engineer by the Purdue School of Mechanical Engineering
1995: Exporter of the Year - Indiana Business Magazine
1997: Northern Indiana Entrepreneur of the Year
1998: Honorary degree from Huntington College

References

Purdue University School of Engineering
Shuttleworth, Inc. corporate archives

American manufacturing businesspeople
1937 births
2003 deaths
MAIFI. The Momentary Average Interruption Frequency Index (MAIFI) is a reliability index used by electric power utilities.  MAIFI is the average number of momentary interruptions that a customer would experience during a given period (typically a year).  Electric power utilities may define momentary interruptions differently, with some considering a momentary interruption to be an outage of less than 1 minute in duration while others may consider a momentary interruption to be an outage of less than 5 minutes in duration.

Calculation
MAIFI is calculated as

Reporting
MAIFI has tended to be less reported than other reliability indicators, such as SAIDI, SAIFI, and CAIDI.  However, MAIFI is useful for tracking momentary power outages, or "blinks," that can be hidden or misrepresented by an overall outage duration index like SAIDI or SAIFI.

Causes
Momentary power outages are often caused by transient faults, such as lightning strikes or vegetation contacting a power line, and many utilities use reclosers to automatically restore power quickly after a transient fault has cleared.

Comparisons
MAIFI is specific to the area ( power utility, state, region, county, power line, etc. ) because of the many variables that affect the measure: high/low lightning, number & type of trees, high/low  winds, etc. Therefore, comparing MAIFI of one power utility to another is not valid and should not be used in this type of benchmarking. It also is difficult to compare this measure of reliability
within a single utility. One year may have had an unusually high number of thunderstorms and thus skew any comparison to another year's MAIFI.

References

Electric power
Reliability indices
Object Technology International. Object Technology International (OTI) was founded in Ottawa, Ontario (Canada) in 1988 and acquired by IBM in 1996. OTI, in conjunction with the IBM development lab in Cary, NC, developed the VisualAge line Smalltalk and Java development tools, that eventually culminated in the open source Eclipse tool platform and integrated development environment (IDE).

OTI continued to operate with many of the same employees as it did when it was purchased by IBM until 2003–2004, when it was gradually disbanded as a distinct entity and its remaining employees absorbed into IBM.

References

External links
Dave Thomas - Travels with Smalltalk: an account of the story of Smalltalk from one of the founders of OTI
Planet OTI  Aggregator for former OTI employee blogs.

Software companies of Canada
Eclipse (software)
1988 establishments in Canada
1988 establishments in Ontario
Software companies established in 1988
Companies established in 1988
Fuji/Rockwell Commander 700. The Fuji/Rockwell Commander 700 is a light transport aircraft which was a joint Japanese-American development between Fuji Heavy Industries and Rockwell International. When Rockwell sold off the general aviation division the agreement was terminated.

Design and development

Design of the Commander 700 started in Japan in 1971 with the designation FA-300, and on 28 June 1974 Fuji signed a collaboration with Rockwell International to design and develop the aircraft as a joint venture. The aircraft was designated the Commander 700 for the North American market. The Commander 700 is a low-wing cantilever monoplane with a conventional tail unit and a retractable tricycle landing gear. The aircraft is powered by two wing mounted Avco Lycoming turbocharged piston engines. The fuselage was designed to be pressurized with accommodation for two crew and four–six passengers. The first prototype made its maiden flight at Fuji's Utsunomiya factory on 13 November 1975 and the second aircraft, assembled by Rockwell, flew at Bethany, Oklahoma on 25 February 1976. A parallel development was the Commander 710 with more powerful engines which first flew on 22 December 1976. In 1979 Rockwell International sold its General Aviation Division to Gulfstream American and the agreement with Fuji was terminated. Fuji then acquired the worldwide manufacturing and marketing rights for the aircraft.

Variants
Commander 700
Powered by two 340hp (254kW) Avco Lycoming TIO-540-R2AD engines.
Commander 710
Powered by two 450hp (335kW) Avco Lycoming TIGO-541 engines.

Specifications (700)

See also

References
Notes

Sources

 The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 1920

External links

 Commander 700 Support Network Wiki  -  NO LONGER MONITORED

FA-300
1970s international civil utility aircraft
Commander 700
Low-wing aircraft
Aircraft first flown in 1975
Twin piston-engined tractor aircraft
Aircraft with retractable tricycle landing gear
Grahame-White Type X. The Grahame-White Type X Charabanc or Aerobus was a 1910s British passenger-carrying biplane designed and built by the Grahame-White Aviation Company based at Hendon Aerodrome, North London.

Development
The Charabanc was built by the Grahame-White company to meet the demand for passenger-carrying flights, which could not be satisfied by the existing two-seat designs. Designed by J. D. North, it was an unequal-span pusher biplane, with ailerons on both upper and lower wings, and a biplane tail unit with three rudders mounted on booms. An elongated nacelle mounted on the lower wing housed the pilot in the front, plus four passengers in two rows of two seats behind.  The wing spars, tail booms and outer interplane struts were of hollow section spruce, and the nacelle and inner struts were of ash.

It first flew in 1913, powered by a 120 hp (89 kW) Austro-Daimler engine, and in this form was flown by Louis Noel with seven passengers aboard to set a British world record on 22 September 1913. On 2 October 1913, he set a world record in carrying nine passengers, staying aloft for nearly twenty minutes. To meet the entry requirements for the 1913 Michelin Cup, which required an all-British aircraft, this was replaced by a British-built 100 hp (75 kW) Green E.6 engine. The Charabanc went on to win the cup, covering a distance of over 300 miles on 9 November 1913, piloted by R.H. Carr.

The first parachute descent from an aircraft in Great Britain was made by W. Newell from the aircraft, at Hendon on 9 May 1914.

Specifications

Notes

References
 Lewis, Peter M. H. British Aircraft 1809-1914 London: Putnam, 1962 p. 284-285
 The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 1998

External links
 The Grahame White Aero-Char-a-BancsFlight magazine 11 October 1913 p. 1113.

Grahame-White aircraft
1910s British airliners
Aircraft first flown in 1913
Methylammonium nitrate. Methylammonium nitrate is an explosive chemical with the molecular formula CH6N2O3, alternately CH3NH3+NO3−. It is the salt formed by the neutralization of methylamine with nitric acid. This substance is also known as methylamine nitrate and monomethylamine nitrate, not to be confused with methyl nitramine or monomethyl nitramine.

Methylammonium nitrate was first used as an explosive ingredient by the Germans during World War II. It was originally called mono-methylamine nitrate, a name that has largely stuck among chemists who formulate energetic materials.

Methylammonium nitrate is somewhat similar in explosive properties to ammonium nitrate (AN) which yields 85% of the power of nitroglycerine when the ammonium nitrate is incorporated into an explosive. The addition of the carbon-containing methyl group in methylammonium nitrate imparts better explosive properties and helps create a more favorable oxygen balance.

After World War II, methylammonium nitrate was largely ignored by explosives manufacturers, in favor of less-costly ammonium nitrate. Ammonium nitrate-fuel oil mixtures (ANFO) were sufficient for most large-diameter explosives uses.

Methylammonium nitrate saw a resurgence when E. I. du Pont de Nemours and Company (DuPont), seeking to lower the cost of its TNT-based Tovex water-gel explosives, incorporated a mixture of methylammonium nitrate with ammonium nitrate which served as a basis for DuPont's water-gels manufactured under the names "Tovex Extra" and "Pourvex Extra". Methylammonium nitrate, also known as PR-M (which stands for "Potomac River—Mono-methylamine nitrate") soon was seen as the possible path toward creating a low-cost blasting agent (water gel explosives) that might replace the explosives based on nitroglycerin (dynamites).

In late 1973, DuPont started to phase out dynamite and replace it with water-gels based on PR-M. However, PR-M proved to have unusual "mass effects". That is, if there was sufficient mass, under certain conditions, PR-M could explode without warning. On August 6, 1974, a tank car containing PR-M blew up in Wenatchee, Washington, rail yard, killing two and injuring 66 others. On July 4, 1976, a PR-M storage with 60,000 pounds (approximately 27,200Kg) of PR-M detonated at DuPont's Potomac River Works at Martinsburg, WV.  Though there was no loss of life, there were many injuries and a substantial loss of property.

References

External links
Crystal structure of monomethylammonium nitrate
methyl ammonium nitrate (PRM) accidental detonation

Explosive chemicals
Nitrates
Methylammonium compounds
Occupancy grid mapping. Occupancy Grid Mapping refers to a family of computer algorithms in probabilistic robotics for mobile robots which address the problem of generating maps from noisy and uncertain sensor measurement data, with the assumption that the robot pose is known. Occupancy grids were first proposed by H. Moravec and A. Elfes in 1985.

The basic idea of the occupancy grid is to represent a map of the environment as an evenly spaced field of binary random variables each representing the presence of an obstacle at that location in the environment. Occupancy grid algorithms compute approximate posterior estimates for these random variables.

Algorithm outline
There are four major components of occupancy grid mapping approach. They are:
 Interpretation
 Integration
 Position estimation
 Exploration

Occupancy grid mapping algorithm
The goal of an occupancy mapping algorithm is to estimate the posterior probability over maps given the data: , where  is the map,  is the set of measurements from time 1 to t, and  is the set of robot poses from time 1 to t. The controls and odometry data play no part in the occupancy grid mapping algorithm since the path is assumed known.

Occupancy grid algorithms represent the map  as a fine-grained grid over the continuous space of locations in the environment. The most common type of occupancy grid maps are 2d maps that describe a slice of the 3d world.

If we let  denote the grid cell with index i (often in 2d maps, two indices are used to represent the two dimensions), then the notation  represents the probability that cell i is occupied.
The computational problem with estimating the posterior  is the dimensionality of the problem: if the map contains 10,000 grid cells (a relatively small map), then the number of possible maps that can be represented by this gridding is . Thus calculating a posterior probability for all such maps is infeasible.

The standard approach, then, is to break the problem down into smaller problems of estimating 

for all grid cells . Each of these estimation problems is then a binary problem. This breakdown is convenient but does lose some of the structure of the problem, since it does not enable modelling dependencies between neighboring cells. Instead, the posterior of a map is approximated by factoring it into
.

Due to this factorization, a binary Bayes filter can be used to estimate the occupancy probability for each grid cell. It is common to use a log-odds representation of the probability that each grid cell is occupied.

See also
Robotic mapping

References

External links
 Lecture notes of 16-831: Statistical Techniques in Robotics at RI CMU

Robot navigation
Qingyun Ma. Qingyun Ma (; born 1965) is a Chinese architect.

Early life and education
Born in Xi'an, Shaanxi province, Ma received a bachelor's degree in Civil Engineering in Architecture from Tsinghua University in Beijing. Later on, he pursued architecture at the Graduate School of Fine Art at the University of Pennsylvania.

Career

Practise
In New York, he worked for several years at the firm Kohn Pedersen Fox. Also he became close to Rem Koolhaas on the first Harvard Project on the City, which he organized resulting in the book The Great Leap Forward.

In 1996, Ma founded MADA s.p.a.m. The architectural firm built over 1,204,000 square meters to date. In 2000, MADA s.p.a.m. formally established itself in Beijing, moving to Shanghai the following year. Included amongst MADA s.p.a.m's works are Qingpu Community Island in Shanghai, the Centennial TV and Radio Center in Xi'an, and Tianyi Square in Ningbo.

Teaching
Ma taught architecture in China at Shenzhen University, Tongji University, and Nanjing University; in Europe at the Berlage, the ETH, the Ecole Speciale d'Architecture in Paris and in Germany; and in the United States at Harvard University, the University of Pennsylvania, and Columbia University. Ma was the Dean of the University of Southern California School of Architecture from January 2007 through June 2017. In April 2020, Ma began serving as a member of the Board of Governors for the historic The School of Architecture founded by Frank Lloyd Wright in 1932.

See also
Ullens Center for Contemporary Art

References

External links 

New Trends of Architecture in Europe and Asia-Pacific 2006-2007

1965 births
Harvard University faculty
Columbia University faculty
University of Southern California faculty
Chinese architects
Tsinghua University alumni
University of Pennsylvania School of Design alumni
Living people
Artists from Xi'an
Educators from Shaanxi
Black Thunder Coal Mine. The Black Thunder Coal Mine is a surface coal mine in the U.S. state of Wyoming, located in the Powder River Basin which contains one of the largest deposits of coal in the world. In 2022, the mine produced  of coal, over 25% of Wyoming's total coal production.

Black Thunder's dragline excavator Ursa Major is the biggest working dragline in North America and the third largest ever made.  It produces enough coal to load up to 20-25 trains per day. Draglines are not used to dig coal, but only strip overburden. Black Thunder operates six draglines.  Coal is excavated by power shovels and loaded into haul trucks.
In 1974, exploration geologist Lewis R. Ladwig drilled exploratory holes on the Jacob sheep ranch.  He was working for ARCO.  He discovered the coal reserves of the basin.
In 2009, the America's Power Factuality Tour stopped at the Black Thunder Coal Mine to report on its role in generating electricity in the US.

In 2010, the Black Thunder Mine produced an estimated 115 million tons of coal, an increase of 34 million tons over 2009. The increase was a result of merging the Jacobs Ranch Mine - and its average 38 million tons per year - into the Black Thunder's annual production. With the acquisition of Jacobs Ranch Mine, Black Thunder is now the world's top coal producer.

In 2011, the America Revealed "Electric Nation" episode aired on PBS and features Thunder Basin's Black Thunder coal mine.

Black Thunder was reported to have mined 101.2 million tons of coal in 2014.

The mine produced 62.2 million tons of coal in 2022, and is the largest producer of coal in the US.

History 
The mine was opened in 1977, and operated by ARCO Coal until it was acquired in 1998 by Arch Coal. For most of its existence, Black Thunder has been the largest mine in the country (by production), but it was surpassed by the nearby North Antelope Rochelle Mine. North Antelope Rochelle was created after Peabody Energy purchased the Rochelle mine adjacent to their North Antelope Mine, and consolidated operations. Arch Coal, Inc. announced on March 9, 2009 that it has agreed to purchase Rio Tinto's Jacobs Ranch mine adjoining Black Thunder, which resulted in Black Thunder once again becoming the largest mine in the world.

The operator claims that "Black Thunder's active mine footprint comprises less than 1/4000th of Wyoming's land area", i.e. up to approximately 25 square miles (60 square km), but reclaimed land and as yet undisturbed areas are not included in this figure and much larger.

Environmental impact 
In 2022, a team of researchers in a paper published in Energy Policy identified the Black Thunder coal mine as a "carbon bomb," a fossil fuel project that would result in more than one gigaton of carbon dioxide emissions if fully extracted and burnt.

References

External links 

Virtual Tour of Black Thunder

Mines in Campbell County, Wyoming
Coal mines in the United States
Surface mines in the United States
Mines in Wyoming
Coal mining in Wyoming