|
Convergent Cross Mapping
Convergent cross mapping (CCM) is a statistical test for a cause-and-effect relationship between two variables that, like the Granger causality test, seeks to resolve the problem that correlation does not imply causation.' Sugihara G., May R., Ye H., Hsieh C., Deyle E., Fogarty M., Munch S., 2012. Detecting Causality in Complex Ecosystems. Science 338:496-500 While Granger causality is best suited for purely stochastic systems where the influences of the causal variables are separable (independent of each other), CCM is based on the theory of dynamical systems and can be applied to systems where causal variables have synergistic effects. As such, CCM is specifically aimed to identify linkage between variables that can appear uncorrelated with each other. Theory In the event one has access to system variables as time series observations, Takens' embedding theorem can be applied. Takens' theorem generically proves that the state space of a dynamical system can be reconstructed fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistical Test
A statistical hypothesis test is a method of statistical inference used to decide whether the data at hand sufficiently support a particular hypothesis. Hypothesis testing allows us to make probabilistic statements about population parameters. History Early use While hypothesis testing was popularized early in the 20th century, early forms were used in the 1700s. The first use is credited to John Arbuthnot (1710), followed by Pierre-Simon Laplace (1770s), in analyzing the human sex ratio at birth; see . Modern origins and early controversy Modern significance testing is largely the product of Karl Pearson ( ''p''-value, Pearson's chi-squared test), William Sealy Gosset (Student's t-distribution), and Ronald Fisher ("null hypothesis", analysis of variance, "significance test"), while hypothesis testing was developed by Jerzy Neyman and Egon Pearson (son of Karl). Ronald Fisher began his life in statistics as a Bayesian (Zabell 1992), but Fisher soon grew disenchanted with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South American Pilchard
''Sardinops'' is a monotypic genus of sardines of the family Clupeidae. The only member of the genus is ''Sardinops sagax''. It is found in the Indo-Pacific and East Pacific oceans. Its length is up to . It has numerous common or vernacular names, some of which more appropriately refer to subspecies, including blue pilchard, Australian pilchard (''S. s. neopilchardus''), blue-bait, Californian pilchard (''S. s. caeruleus''), Peruvian Pacific sardine (''S. s. sagax''), South American pilchard, Chilean sardine (''S. s. sagax''), Japanese pilchard (''S. s. melanostictus''), Pacific sardine, and Southern African pilchard (''S. s. ocellatus''). South Australian sardine fishery The South Australian sardine fishery targets ''Sardinops sagax'' and is the highest yielding single species fishery in Australia by volume. The fishery employs the technique of purse seining. Schools of sardines are encircled by a net up to 1 kilometre in length which is then drawn closed at the bottom. The ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predictive Analytics
Predictive analytics encompasses a variety of statistical techniques from data mining, predictive modeling, and machine learning that analyze current and historical facts to make predictions about future or otherwise unknown events. In business, predictive models exploit patterns found in historical and transactional data to identify risks and opportunities. Models capture relationships among many factors to allow assessment of risk or potential associated with a particular set of conditions, guiding decision-making for candidate transactions. The defining functional effect of these technical approaches is that predictive analytics provides a predictive score (probability) for each individual (customer, employee, healthcare patient, product SKU, vehicle, component, machine, or other organizational unit) in order to determine, inform, or influence organizational processes that pertain across large numbers of individuals, such as in marketing, credit risk assessment, fraud detecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonlinear Systems
In mathematics and science, a nonlinear system is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other scientists because most systems are inherently nonlinear in nature. Nonlinear dynamical systems, describing changes in variables over time, may appear chaotic, unpredictable, or counterintuitive, contrasting with much simpler linear systems. Typically, the behavior of a nonlinear system is described in mathematics by a nonlinear system of equations, which is a set of simultaneous equations in which the unknowns (or the unknown functions in the case of differential equations) appear as variables of a polynomial of degree higher than one or in the argument of a function which is not a polynomial of degree one. In other words, in a nonlinear system of equations, the equation(s) to be solved cannot be written as a linear combination of the un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Sugihara
George Sugihara (born in Tokyo, Japan) is currently a professor of biological oceanography in the Physical Oceanography Research Division at the Scripps Institution of Oceanography, where he is the inaugural holder of the McQuown Chair in Natural Science. Sugihara is a theoretical biologist who works across a variety of fields ranging from ecology and landscape ecology, to epidemiology, to genetics, to geoscience and atmospheric science, to quantitative finance and economics. His work involves inductive theoretical approaches to understanding nature from observational data. The general approach is different from most theory and involves minimalist inductive theory – Inductive data-driven explorations of nature using minimal assumptions. The aim is to avoid inevitable assumptions of deductive first-principle models and produce an understanding that passes the validation test of out-of-sample prediction. His initial work on fisheries as complex, chaotic systems led to work on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Dynamics
Complex dynamics is the study of dynamical systems defined by Iterated function, iteration of functions on complex number spaces. Complex analytic dynamics is the study of the dynamics of specifically analytic functions. Techniques *General **Montel's theorem **Poincaré metric **Schwarz lemma **Riemann mapping theorem **Carathéodory's theorem (conformal mapping) **Böttcher's equation *Combinatorics, Combinatorial ** Hubbard trees ** Spider algorithm ** Tuning **Lamination (topology), Laminations **Cantor function, Devil's Staircase algorithm (Cantor function) **Orbit portraits **Jean-Christophe Yoccoz, Yoccoz puzzles Parts * Holomorphic dynamics (dynamics of holomorphic functions) ** in one complex variable ** in several complex variables * Conformal dynamics unites holomorphic dynamics in one complex variable with differentiable dynamics in one real variable. See also *Arithmetic dynamics *Chaos theory *Complex analysis *Complex quadratic polynomial *Fatou set *Infinite co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Dynamics
System dynamics (SD) is an approach to understanding the nonlinear behaviour of complex systems over time using stocks, flows, internal feedback loops, table functions and time delays. Overview System dynamics is a methodology and mathematical modeling technique to frame, understand, and discuss complex issues and problems. Originally developed in the 1950s to help corporate managers improve their understanding of industrial processes, SD is currently being used throughout the public and private sector for policy analysis and design. Convenient graphical user interface (GUI) system dynamics software developed into user friendly versions by the 1990s and have been applied to diverse systems. SD models solve the problem of simultaneity (mutual causation) by updating all variables in small time increments with positive and negative feedbacks and time delays structuring the interactions and control. The best known SD model is probably the 1972 ''The Limits to Growth''. This model f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empirical Dynamic Modeling
Empirical dynamic modeling (EDM) is a framework for analysis and prediction of nonlinear dynamical systems. Applications include population dynamics,'Dixon, P. A., et al. 1999. Episodic fluctuations in larval supply. Science 283:1528–1530'Ushio, M., Hsieh, Ch., Masuda, R. et al., 2018. Fluctuating interaction network and time-varying stability of a natural fish community. Nature 554, 360–363 ecosystem service, medicine, neuroscience,'McBride, J. C., et al. Sugihara causality analysis of scalp EEG for detection of early Alzheimer's disease. Neuroimage-Clinical 7:258–265 (2015)'Tajima S, Yanagawa T, Fujii N, Toyoizumi T (2015) Untangling Brain-Wide Dynamics in Consciousness by Cross-Embedding. PLoS Comput Biol 11(11): e1004537. https://doi.org/10.1371/journal.pcbi.1004537'W. Watanakeesuntorn et al., "Massively Parallel Causal Inference of Whole Brain Dynamics at Single Neuron Resolution," 2020 IEEE 26th International Conference on Parallel and Distributed Systems (ICPADS), 2020 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Current
The California Current is a cold water Pacific Ocean current that moves southward along the western coast of North America, beginning off southern British Columbia and ending off southern Baja California Sur. It is considered an Eastern boundary current due to the influence of the North American coastline on its course. It is also one of five major coastal currents affiliated with strong upwelling zones, the others being the Humboldt Current, the Canary Current, the Benguela Current, and the Somali Current. The California Current is part of the North Pacific Gyre, a large swirling current that occupies the northern basin of the Pacific. Physical properties The movement of Alaskan and northern ocean currents southward down the west coast results in much cooler ocean temperatures than at comparable latitudes on the east coast of the United States, where ocean currents come from the Caribbean and tropical Atlantic. The cooler ocean current along the west coast also makes summer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Californian Anchovy
The Californian anchovy or northern anchovy (''Engraulis mordax'') is a species of anchovy found in the Pacific Ocean, ranging from Mexico to British Columbia. Relationship with humans Commercial fishing As sardine populations declined in the Pacific during the 1940s and 50's, fish packers in United States of America, America started canning the more abundant local anchovies. Total hauls increased over this time from 960 tons in 1946 to 9,464 tons in 1947 and peaking at almost 43,000 tons in 1953. From 1949 to 1955, they were restricted for all uses but bait fish in California. In 2010, reported American hauls totaled 2,100 metric tons. Most Californian anchovies today are fished for use in animal feed and as bait fish. Recreational fishing They are taken by anglers for use as bait or for personal consumption. References External links * {{Taxonbar, from=Q989747 Engraulis, California anchovy Western North American coastal fauna Fish of the Western United States Fauna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empirical Dynamic Modeling
Empirical dynamic modeling (EDM) is a framework for analysis and prediction of nonlinear dynamical systems. Applications include population dynamics,'Dixon, P. A., et al. 1999. Episodic fluctuations in larval supply. Science 283:1528–1530'Ushio, M., Hsieh, Ch., Masuda, R. et al., 2018. Fluctuating interaction network and time-varying stability of a natural fish community. Nature 554, 360–363 ecosystem service, medicine, neuroscience,'McBride, J. C., et al. Sugihara causality analysis of scalp EEG for detection of early Alzheimer's disease. Neuroimage-Clinical 7:258–265 (2015)'Tajima S, Yanagawa T, Fujii N, Toyoizumi T (2015) Untangling Brain-Wide Dynamics in Consciousness by Cross-Embedding. PLoS Comput Biol 11(11): e1004537. https://doi.org/10.1371/journal.pcbi.1004537'W. Watanakeesuntorn et al., "Massively Parallel Causal Inference of Whole Brain Dynamics at Single Neuron Resolution," 2020 IEEE 26th International Conference on Parallel and Distributed Systems (ICPADS), 2020 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Causality
Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the cause is partly responsible for the effect, and the effect is partly dependent on the cause. In general, a process has many causes, which are also said to be ''causal factors'' for it, and all lie in its past. An effect can in turn be a cause of, or causal factor for, many other effects, which all lie in its future. Some writers have held that causality is metaphysically prior to notions of time and space. Causality is an abstraction that indicates how the world progresses. As such a basic concept, it is more apt as an explanation of other concepts of progression than as something to be explained by others more basic. The concept is like those of agency and efficacy. For this reason, a leap of intuition may be needed to grasp it. Accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
