Operations research

Operations research is a discipline that deals with the application of advanced analytical methods to help make better decisions. Further, the term operational analysis is used in the British military as an intrinsic part of capability development and assurance. In particular, operational analysis forms part of the Combined Operational Effectiveness and Investment Appraisals, which support British defense capability acquisition decision-making, it is considered to be a sub-field of applied mathematics. The terms management science and decision science are sometimes used as synonyms. Employing techniques from other mathematical sciences, such as mathematical modeling, statistical analysis, mathematical optimization, operations research arrives at optimal or near-optimal solutions to complex decision-making problems; because of its emphasis on human-technology interaction and because of its focus on practical applications, operations research has overlap with other disciplines, notably industrial engineering and operations management, draws on psychology and organization science.

Operations research is concerned with determining the extreme values of some real-world objective: the maximum or minimum. Originating in military efforts before World War II, its techniques have grown to concern problems in a variety of industries. Operational research encompasses the development and the use of a wide range of problem-solving techniques and methods applied in the pursuit of improved decision-making and efficiency, such as simulation, mathematical optimization, queueing theory and other stochastic-process models, Markov decision processes, econometric methods, data envelopment analysis, neural networks, expert systems, decision analysis, the analytic hierarchy process. Nearly all of these techniques involve the construction of mathematical models that attempt to describe the system; because of the computational and statistical nature of most of these fields, OR has strong ties to computer science and analytics. Operational researchers faced with a new problem must determine which of these techniques are most appropriate given the nature of the system, the goals for improvement, constraints on time and computing power.

The major sub-disciplines in modern operational research, as identified by the journal Operations Research, are: Computing and information technologies Financial engineering Manufacturing, service sciences, supply chain management Policy modeling and public sector work Revenue management Simulation Stochastic models Transportation In the decades after the two world wars, the tools of operations research were more applied to problems in business and society. Since that time, operational research has expanded into a field used in industries ranging from petrochemicals to airlines, finance and government, moving to a focus on the development of mathematical models that can be used to analyse and optimize complex systems, has become an area of active academic and industrial research. In the 17th century mathematicians like Christiaan Huygens and Blaise Pascal tried to solve problems involving complex decisions with probability. Others in the 18th and 19th centuries solved these types of problems with combinatorics.

Charles Babbage's research into the cost of transportation and sorting of mail led to England's universal "Penny Post" in 1840, to studies into the dynamical behaviour of railway vehicles in defence of the GWR's broad gauge. Beginning in the 20th century, study of inventory management could be considered the origin of modern operations research with economic order quantity developed by Ford W. Harris in 1913. Operational research may have originated in the efforts of military planners during World War I. Percy Bridgman brought operational research to bear on problems in physics in the 1920s and would attempt to extend these to the social sciences. Modern operational research originated at the Bawdsey Research Station in the UK in 1937 as the result of an initiative of the station's superintendent, A. P. Rowe. Rowe conceived the idea as a means to analyse and improve the working of the UK's early-warning radar system, code-named "Chain Home". Rowe analysed the operating of the radar equipment and its communication networks, expanding to include the operating personnel's behaviour.

This allowed remedial action to be taken. Scientists in the United Kingdom, in the United States looked for ways to make better decisions in such areas as logistics and training schedules The modern field of operational research arose during World War II. In the World War II era, operational research was defined as "a scientific method of providing executive departments with a quantitative basis for decisions regarding the operations under their control". Other names for it included quantitative management. During the Second World War close to 1,000 men and women in Britain were engaged in operational research. About 200 operational research scientists worked for the British Army. Patrick Blackett worked for several different organizations during the war. Early in the war while working for the Royal Aircraft Establishment he set up a team known as the "Circus" which helped to reduce the number of anti-aircraft artillery ro

Cosmos 1

Cosmos 1 was a project by Cosmos Studios and The Planetary Society to test a solar sail in space. As part of the project, an unmanned solar sail spacecraft christened Cosmos 1 was launched into space at 15:46:09 EDT on June 21, 2005 from the submarine Borisoglebsk in the Barents Sea. However, a rocket failure prevented the spacecraft from reaching its intended orbit. Once in orbit, the spacecraft was supposed to deploy a large sail, upon which photons from the Sun would push, thereby increasing the spacecraft's velocity. Had the mission been successful, it would have been the first orbital use of a solar sail to speed up a spacecraft, as well as the first space mission by a space advocacy group; the project budget was US$4 million. The Planetary Society planned to raise another $4 million for Cosmos 2, a reimplementation of the experiment provisionally to be launched on a Soyuz resupply mission to the International Space Station; the Discovery Channel was an early investor. However, advances in technology and the greater availability of lower mass piggyback slots on more launch vehicles led to a redesign similar to NanoSail-D, called LightSail-1, announced in November 2009.

To test the solar sail concept, the Cosmos 1 project launched an orbital spacecraft they named Cosmos 1 with a full complement of eight sail blades on June 21, 2005 — the summer solstice. The spacecraft had a mass of 100 kg and consisted of eight triangular sail blades which would be deployed from a central hub after launch by the inflating of structural tubes; the sail blades were each 15 m long, had a total surface area of 600 square meters, were made of aluminized reinforced PET film. The spacecraft was launched on a Volna rocket from a Russian Delta III submarine, the Borisoglebsk, submerged in the Barents Sea; the spacecraft's initial circular orbit would have been at an altitude of about 800 km, where it would have unfurled the sails. The sails would have raised the spacecraft to a higher earth orbit. "Cosmos 1 might boost its orbit 31 to 62 miles over the expected 30-day life of the mission," said Louis Friedman of the Planetary Society. The mission was expected to end within a month of launch as the mylar of the blades would degrade in sunlight.

The solar sail craft could have been used to measure the effect of artificial microwaves aimed at it from a radar installation. A 70 m dish at the Goldstone facility of NASA's Deep Space Network would have been used to irradiate the sail with a 450 kW beam; this experiment in beam-powered propulsion would only have been attempted after the prime mission objective of controlled solar sail flight was achieved. The craft would have been visible to the naked eye from most of the Earth's surface: the planned orbit had an inclination of 80°, so it would have been visible from latitudes of up to 80° north and south. A network of tracking stations around the world, including the Tarusa station, 75 miles south of Moscow, the Space Sciences Laboratory at the University of California-Berkeley, tried to maintain contact with the solar sail during the mission. Mission control was based at the Russian company NPO Lavochkin in Moscow — a center that the Planetary Society calls Mission Operations Moscow; the craft would have been accelerating during each orbit as a result of the radiation pressure of photons colliding with the sails.

As photons reflected off the surface of the sails, they would transfer momentum to them. As there would be no air resistance to oppose the velocity of the spacecraft, acceleration would be proportional to the number of photons colliding with it per unit time. Sunlight amounts to a tiny 5×10−4 m/s² acceleration in the vicinity of the Earth. Over one day, the spacecraft's speed would reach 45 m/s. At that speed, a craft would reach Pluto, a distant dwarf planet in the solar system, in less than five years, although in practice the acceleration of a sail drops as the spacecraft gets farther from the Sun. However, in the vicinity of Earth, a solar sail's acceleration is larger than that of some other propulsion techniques. Besides the main spacecraft, launched in June 2005, the Cosmos 1 project has funded two other craft: A suborbital test was attempted in 2001 with only two sail blades; the spacecraft failed to separate from the rocket. A second orbital spacecraft was launched, in May 2015. One of Cosmos 1's solar sail blades was displayed at the Rockefeller Center office complex in New York City in 2003.

Cosmos 1 homepage at the Planetary Society Planetary Society's solar sail updates and press releases - current information about the Cosmos 2 follow-on project. Cosmos 1 page from Cosmos Studios Near-Term Beamed Sail Propulsion Missions: Cosmos 1 and Sun-Diver at the Wayback Machine Space technology: Setting sail for history Space yacht rides to stars on rays of sunlight Cosmos 1 to test solar sail Cosmos 1 videos