John Hammersley
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John Hammersley
John Michael Hammersley, (21 March 1920 – 2 May 2004) was a British mathematician best known for his foundational work in the theory of self-avoiding walks and percolation theory. Early life and education Hammersley was born in Helensburgh in Dunbartonshire, and educated at Sedbergh School. He started reading mathematics at Emmanuel College, Cambridge but was called up to join the Royal Artillery in 1941. During his time in the army he worked on ballistics. He graduated in mathematics in 1948. He never studied for a PhD but was awarded an ScD by Cambridge University and a DSc by Oxford University in 1959. Academic career With Jillian Beardwood and J.H. Halton, Hammersley is known for the Beardwood-Halton-Hammersley Theorem.  Published by the Cambridge Philosophical Society in a 1959 article entitled “The Shortest Path Through Many Points,” the theorem provides a practical solution to the “traveling salesman problem.” He held a number of positions, both in and out ...
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Helensburgh
Helensburgh (; gd, Baile Eilidh) is an affluent coastal town on the north side of the Firth of Clyde in Scotland, situated at the mouth of the Gareloch. Historically in Dunbartonshire, it became part of Argyll and Bute following local government reorganisation in 1996. Geography and geology Helensburgh is northwest of Glasgow. The town faces south towards Greenock across the Firth of Clyde, which is approximately wide at this point. Ocean-going ships can call at Greenock, but the shore at Helensburgh is very shallow, although to the west of the town the Gareloch is deep. Helensburgh lies at the western mainland end of the Highland Boundary Fault. This means that the hills to the north of Helensburgh lie in the Highlands, whereas the land to the south of Helensburgh is in the Lowlands or Central Belt of Scotland. Consequently, there is a wide variety of landscape in the surrounding area – for example, Loch Lomond (part of Scotland's first National Park) is only over ...
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Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises thirteen Regular Army regiments, King's Troop, Royal Horse Artillery, the King's Troop Royal Horse Artillery and five Army Reserve (United Kingdom), Army Reserve regiments. History Formation to 1799 Artillery was used by the English army as early as the Battle of Crécy in 1346, while Henry VIII established it as a semi-permanent function in the 16th century. Until the early 18th century, the majority of British regiments were raised for specific campaigns and disbanded on completion. An exception were gunners based at the Tower of London, Portsmouth and other forts around Britain, who were controlled by the Ordnance Office and stored and maintained equipment and provided personnel for field artillery Artillery is a class of heav ...
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1920 Births
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band) 19 was a Japanese pop/folk duo. Its members were Kenji Okahira and Keigo Iwase The Japanese language has a system of honorific speech, referred to as , parts of speech that show respect. Their use is mandatory in many social situations. Ho ..., a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album '' 63/19'' by Kool A.D. * '' Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album ''Refugee (Bad4 ...
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Low-discrepancy Sequence
In mathematics, a low-discrepancy sequence is a sequence with the property that for all values of ''N'', its subsequence ''x''1, ..., ''x''''N'' has a low discrepancy. Roughly speaking, the discrepancy of a sequence is low if the proportion of points in the sequence falling into an arbitrary set ''B'' is close to proportional to the measure of ''B'', as would happen on average (but not for particular samples) in the case of an equidistributed sequence. Specific definitions of discrepancy differ regarding the choice of ''B'' (hyperspheres, hypercubes, etc.) and how the discrepancy for every B is computed (usually normalized) and combined (usually by taking the worst value). Low-discrepancy sequences are also called quasirandom sequences, due to their common use as a replacement of uniformly distributed random numbers. The "quasi" modifier is used to denote more clearly that the values of a low-discrepancy sequence are neither random nor pseudorandom, but such sequences share some ...
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Constructions Of Low-discrepancy Sequences
In mathematics, a low-discrepancy sequence is a sequence with the property that for all values of ''N'', its subsequence ''x''1, ..., ''x''''N'' has a low discrepancy. Roughly speaking, the discrepancy of a sequence is low if the proportion of points in the sequence falling into an arbitrary set ''B'' is close to proportional to the measure of ''B'', as would happen on average (but not for particular samples) in the case of an equidistributed sequence. Specific definitions of discrepancy differ regarding the choice of ''B'' (hyperspheres, hypercubes, etc.) and how the discrepancy for every B is computed (usually normalized) and combined (usually by taking the worst value). Low-discrepancy sequences are also called quasirandom sequences, due to their common use as a replacement of uniformly distributed random numbers. The "quasi" modifier is used to denote more clearly that the values of a low-discrepancy sequence are neither random nor pseudorandom, but such sequences share some ...
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Oxford University
Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the University of Oxford, the oldest university in the English-speaking world; it has buildings in every style of English architecture since late Anglo-Saxon. Oxford's industries include motor manufacturing, education, publishing, information technology and science. History The history of Oxford in England dates back to its original settlement in the Saxon period. Originally of strategic significance due to its controlling location on the upper reaches of the River Thames at its junction with the River Cherwell, the town grew in national importance during the early Norman period, and in the late 12th century became home to the fledgling University of Oxford. The city was besieged during The Anarchy in 1142. The university rose to domi ...
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Reader (academic Rank)
The title of reader in the United Kingdom and some universities in the Commonwealth of Nations, for example India, Australia and New Zealand, denotes an appointment for a senior academic with a distinguished international reputation in research or scholarship. In the traditional hierarchy of British and other Commonwealth universities, reader (and principal lecturer in the new universities) are academic ranks above senior lecturer and below professor, recognising a distinguished record of original research. Reader is similar to a professor without a chair, similar to the distinction between ''professor extraordinarius'' and ''professor ordinarius'' at some European universities, professor and chaired professor in Hong Kong and "professor name" (or associate professor) and chaired professor in Ireland. Readers and professors in the UK would correspond to full professors in the United States.Graham WebbMaking the most of appraisal: career and professional development planning fo ...
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New Math
New Mathematics or New Math was a dramatic but temporary change in the mathematics education, way mathematics was taught in American grade schools, and to a lesser extent in European countries and elsewhere, during the 1950s1970s. Curriculum topics and teaching practices were changed in the U.S. shortly after the Sputnik crisis. The goal was to boost students' science education and mathematical skill to meet the technological threat of Soviet engineers, reputedly highly skilled mathematicians. Overview After the Sputnik launch in 1957, the U.S. National Science Foundation funded the development of several new curricula in the sciences, such as the Physical Science Study Committee high school physics curriculum, Biological Sciences Curriculum Study in biology, anCHEM Studyin chemistry. Several mathematics curriculum development efforts were also funded as part of the same initiative, such as th School Mathematics Study Group, anUniversity of Illinois Committee on School Mathe ...
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Problem Solving
Problem solving is the process of achieving a goal by overcoming obstacles, a frequent part of most activities. Problems in need of solutions range from simple personal tasks (e.g. how to turn on an appliance) to complex issues in business and technical fields. The former is an example of simple problem solving (SPS) addressing one issue, whereas the latter is complex problem solving (CPS) with multiple interrelated obstacles. Another classification is into well-defined problems with specific obstacles and goals, and ill-defined problems in which the current situation is troublesome but it is not clear what kind of resolution to aim for. Similarly, one may distinguish formal or fact-based problems requiring psychometric intelligence, versus socio-emotional problems which depend on the changeable emotions of individuals or groups, such as tactful behavior, fashion, or gift choices. Solutions require sufficient resources and knowledge to attain the goal. Professionals such as ...
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Moving Sofa Problem
In mathematics, the moving sofa problem or sofa problem is a two-dimensional idealisation of real-life furniture-moving problems and asks for the rigid two-dimensional shape of largest area that can be maneuvered through an L-shaped planar region with legs of unit width. The area thus obtained is referred to as the ''sofa constant''. The exact value of the sofa constant is an open problem. The currently leading solution, by Joseph L. Gerver, has a value of approximately 2.2195 and is thought to be close to the optimal, based upon subsequent study and theoretical bounds. History The first formal publication was by the Austrian-Canadian mathematician Leo Moser in 1966, although there had been many informal mentions before that date. Bounds Work has been done on proving that the sofa constant (A) cannot be below or above certain values (lower bounds and upper bounds). Lower An obvious lower bound is A \geq \pi/2 \approx 1.57. This comes from a sofa that is a half- disk of unit ra ...
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Traveling Salesman Problem
The travelling salesman problem (also called the travelling salesperson problem or TSP) asks the following question: "Given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the origin city?" It is an NP-hard problem in combinatorial optimization, important in theoretical computer science and operations research. The travelling purchaser problem and the vehicle routing problem are both generalizations of TSP. In the theory of computational complexity, the decision version of the TSP (where given a length ''L'', the task is to decide whether the graph has a tour of at most ''L'') belongs to the class of NP-complete problems. Thus, it is possible that the worst-case running time for any algorithm for the TSP increases superpolynomially (but no more than exponentially) with the number of cities. The problem was first formulated in 1930 and is one of the most intensively studi ...
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