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IThink
STELLA (short for Systems Thinking, Experimental Learning Laboratory with Animation; also marketed as iThink) is a visual programming language for system dynamics modeling introduced by Barry Richmond in 1985. The program, distributed by isee systems (formerly High Performance Systems) allows users to run models created as graphical representations of a system using four fundamental building blocks. STELLA has been used in academia as a teaching tool and has been utilized in a variety of research and business applications. The program has received positive reviews, being praised in particular for its ease of use and low cost. History While working at the Massachusetts Institute of Technology in the 1960s, Jay Wright Forrester developed the earliest understanding of system dynamics which he argued could only be understood using models. Dartmouth College systems science professor Barry Richmond founded High Performance Systems in 1984. With the financial support of Analog Devic ...
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Barry Richmond
Barry Marshall Richmond (14 November 1946 – 3 August 2002) was an American systems scientist, and former managing director of High Performance Systems, Inc (HPS), an organization providing software and consulting services to build the capacity of people to understand and improve the workings of dynamic systems. He is known as a leader in the field of systems thinking and system dynamics and for the development of the STELLA/iThink modelling environment for simulation. Biography Richmond received a B.A. in psychology from Syracuse University, an MBA from Columbia University, an MA in operations research from Case Western Reserve University, and in 1979 a PhD in system dynamics from Massachusetts Institute of Technology, where he was a graduate student of Jay Wright Forrester.Arie de Geus (2002). ''The living company''. Harvard Business Press. . p.68. At the MIT Sloan School of Management Richmond became intrigued with the possibilities of creating a software package to promote ...
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Apple Computer
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user interfaces, in ...
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Visual Programming Language
In computing, a visual programming language (visual programming system, VPL, or, VPS) is any programming language that lets users create programs by manipulating program elements ''graphically'' rather than by specifying them ''textually''. A VPL allows programming with visual expressions, spatial arrangements of text and graphic symbols, used either as elements of syntax or secondary notation. For example, many VPLs (known as ''dataflow'' or ''diagrammatic programming'') are based on the idea of "boxes and arrows", where boxes or other screen objects are treated as entities, connected by arrows, lines or arcs which represent relations. Definition VPLs may be further classified, according to the type and extent of visual expression used, into icon-based languages, form-based languages, and diagram languages. Visual programming environments provide graphical or iconic elements which can be manipulated by users in an interactive way according to some specific spatial grammar for p ...
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Numerical Analysis
Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic computation, symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods that attempt at finding approximate solutions of problems rather than the exact ones. Numerical analysis finds application in all fields of engineering and the physical sciences, and in the 21st century also the life and social sciences, medicine, business and even the arts. Current growth in computing power has enabled the use of more complex numerical analysis, providing detailed and realistic mathematical models in science and engineering. Examples of numerical analysis include: ordinary differential equations as found in celestial mechanics (predicting the motions of planets, stars and galaxies), numerical linear algebra in data analysis, and stochastic differential equations and Markov chains for simulating living ce ...
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Middle School
A middle school (also known as intermediate school, junior high school, junior secondary school, or lower secondary school) is an educational stage which exists in some countries, providing education between primary school and secondary school. The concept, regulation and classification of middle schools, as well as the ages covered, vary between and sometimes within countries. Afghanistan In Afghanistan, middle school includes grades 6, 7, and 8, consisting of students from ages 11 to 14. Algeria In Algeria, a middle school includes 4 grades: 6, 7, 8, and 9, consisting of students from ages 11–15. Argentina The of secondary education (ages 11–14) is roughly equivalent to middle school. Australia No regions of Australia have segregated middle schools, as students go directly from primary school (for years K/preparatory–6) to secondary school (years 7–12, usually referred to as high school). As an alternative to the middle school model, some secondary schools classi ...
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Drainage Basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the '' drainage divide'', made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, "watershed" is used only in its original sense, that of a drainage divide. In a closed drainage basin, or endorheic basin, the water converges to a single point inside the basin, known as a sink, which may be a permanent lake, a dry lake, or a point where surface water is lost underground. Drainage basins are similar ...
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Project-based Learning
Project-based learning (PBL) is a student-centered pedagogy that involves a dynamic classroom approach in which it is believed that students acquire a deeper knowledge through active exploration of real-world challenges and problems. Students learn about a subject by working for an extended period of time to investigate and respond to a complex question, challenge, or problem. It is a style of active learning and inquiry-based learning. PBL contrasts with paper-based, rote memorization, or teacher-led instruction that presents established facts or portrays a smooth path to knowledge by instead posing questions, problems or scenarios. History John Dewey is recognized as one of the early proponents of project-based education or at least its principles through his idea of "learning by doing". In ''My Pedagogical Creed'' (1897) Dewey enumerated his beliefs including the view that "the teacher is not in the school to impose certain ideas or to form certain habits in the child, but ...
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Hamlet
''The Tragedy of Hamlet, Prince of Denmark'', often shortened to ''Hamlet'' (), is a tragedy written by William Shakespeare sometime between 1599 and 1601. It is Shakespeare's longest play, with 29,551 words. Set in Denmark, the play depicts Prince Hamlet and his attempts to exact revenge against his uncle, Claudius, who has murdered Hamlet's father in order to seize his throne and marry Hamlet's mother. ''Hamlet'' is considered among the "most powerful and influential tragedies in the English language", with a story capable of "seemingly endless retelling and adaptation by others". There are many works that have been pointed to as possible sources for Shakespeare's play—from ancient Greek tragedies to Elizabethan plays. The editors of the Arden Shakespeare question the idea of "source hunting", pointing out that it presupposes that authors always require ideas from other works for their own, and suggests that no author can have an original idea or be an originator. When ...
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William Shakespeare
William Shakespeare ( 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's national poet and the " Bard of Avon" (or simply "the Bard"). His extant works, including collaborations, consist of some 39 plays, 154 sonnets, three long narrative poems, and a few other verses, some of uncertain authorship. His plays have been translated into every major living language and are performed more often than those of any other playwright. He remains arguably the most influential writer in the English language, and his works continue to be studied and reinterpreted. Shakespeare was born and raised in Stratford-upon-Avon, Warwickshire. At the age of 18, he married Anne Hathaway, with whom he had three children: Susanna, and twins Hamnet and Judith. Sometime between 1585 and 1592, he began a successful career in London as an ...
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History Of Easter Island
Geologically one of the youngest inhabited territories on Earth, Easter Island, located in the mid-Pacific Ocean, was, for most of its history, one of the most isolated. Its inhabitants, the Rapa Nui, have endured famines, epidemics of disease and cannibalism, civil war, environmental collapse, slave raids, various colonial contacts, and have seen their population crash on more than one occasion. The ensuing cultural legacy has brought the island notoriety out of proportion to the number of its inhabitants. First settlers Early European visitors to Easter Island recorded the local oral traditions about the original settlers. In these traditions, Easter Islanders claimed that a chief Hotu Matu'a arrived on the island in one or two large canoes with his wife and extended family. They are believed to have been Polynesian. There is considerable uncertainty about the accuracy of this legend as well as the date of settlement. Published literature suggests the island was settled aroun ...
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Daisyworld
Daisyworld, a computer simulation, is a hypothetical world orbiting a star whose radiant energy is slowly increasing or decreasing. It is meant to mimic important elements of the Earth-Sun system, and was introduced by James Lovelock and Andrew Watson in a paper published in 1983 to illustrate the plausibility of the Gaia hypothesis. In the original 1983 version, Daisyworld is seeded with two varieties of daisy as its only life forms: black daisies and white daisies. White petaled daisies reflect light, while black petaled daisies absorb light. The simulation tracks the two daisy populations and the surface temperature of Daisyworld as the sun's rays grow more powerful. The surface temperature of Daisyworld remains almost constant over a broad range of solar output. Mathematical model to sustain the Gaia hypothesis The purpose of the model is to demonstrate that feedback mechanisms can evolve from the actions or activities of self-interested organisms, rather than th ...
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Forest Biomass Carbon Model In STELLA
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' (FRA 2020) found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the predominant terrestrial ecosystem of Earth, and are found around the globe. More than half of the world's forests are found in only five countries (Brazil, Canada, China, Russia, and the United States). The largest share of forests (45 percent) are in th ...
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