|
Aggregation Websites
Aggregation may refer to: Business and economics * Aggregation problem (economics) * Purchasing aggregation, the joining of multiple purchasers in a group purchasing organization to increase their buying power * Community Choice Aggregation, the joining of geographically contiguous communities to bypass a conventional energy utility monopoly and seek a greener energy service Computer science and telecommunication * Aggregate function, a type of function in data processing * Aggregation, a form of object composition in object-oriented programming * Link aggregation, using multiple Ethernet network cables/ports in parallel to increase link speed * Packet aggregation, joining multiple data packets for transmission as a single unit to increase network efficiency * Route aggregation, the process of forming a supernet in computer networking * Aggregation, a process by which Australian country television markets were combined in the late 1980s and 1990s; see Regional television in Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregation Problem
An ''aggregate'' in economics is a summary measure. It replaces a vector that is composed of many real numbers by a single real number, or a scalar. Consequently there occur various problems that are inherent in the formulations that use aggregated variables.Franklin M. Fisher (1987). "aggregation problem," '' The New Palgrave: A Dictionary of Economics'', v. 1, pp.53-55 The aggregation problem is the difficult problem of finding a valid way to treat an empirical or theoretical aggregate as if it reacted like a less-aggregated measure, say, about behavior of an individual agent as described in general microeconomic theory. The second meaning of "aggregation problem" is the theoretical difficulty in using and treating laws and theorems that include aggregate variables. A typical example is the aggregate production function. Another famous problem is Sonnenschein-Mantel-Debreu theorem. Most of macroeconomic statements comprise this problem. Examples of aggregates in micro- and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and, unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: ''adhesion''. Second, they change shape, turn on receptors and secrete chemical messengers: ''activati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agrégation
In France, the ''agrégation'' () is a competitive examination for civil service in the French public education system. Candidates for the examination, or ''agrégatifs'', become ''agrégés'' once they are admitted to the position of ''professeur agrégé''. In France, ''professeurs agrégés'' are distinguished from ''professeurs certifiés'' recruited through the CAPES training. The ''agrégés'' are usually expected to teach in sixth-form colleges ('' lycées'') and universities, while the ''certifiés'' usually teach in secondary schools ('' collèges''), although there is a significant overlap. The examination may require more than a year of preparation. The difficulty and selectivity (quota) vary from one discipline to another: there are about 300 such positions open each year for mathematics alone, but usually fewer positions are made available for humanities and social sciences (for example, 61 positions for philosophy were offered in 2018) and perhaps only one seat i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregator (other)
Aggregator may refer to: *Job ads aggregator, a website that aggregates job ads from various job boards, multiposter sites, as well as from direct employers and recruiting agencies *News aggregator, software or a website that aggregates news from various sources *Poll aggregator, a website that aggregates polling data to gauge public sentiment on key political issues or to measure likely support for a candidate or party in an upcoming election. *Review aggregator, a website that aggregates reviews of movies or other products or services *Search aggregator, software that aggregates search results from various search engines *Social network aggregation, the collection of content from multiple social network services *Video aggregator, a website that aggregates online videos from various sources See also *Aggregate (other) *Aggregation (other) Aggregation may refer to: Business and economics * Aggregation problem (economics) * Purchasing aggregation, the joining of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate (other)
Aggregate or aggregates may refer to: Computing and mathematics * collection of objects that are bound together by a root entity, otherwise known as an aggregate root. The aggregate root guarantees the consistency of changes being made within the aggregate by forbidding external objects from holding references to its members. * Aggregate (data warehouse), a part of the dimensional model that is used to speed up query time by summarizing tables * Aggregate analysis, a technique used in amortized analysis in computer science, especially in analysis of algorithms * Aggregate class, a type of class supported by C++ * Aggregate data, in statistics, data combined from several measurements * Aggregate function, aggregation function, in database management is a function wherein the values of multiple rows are grouped together to form a single summary value * Aggregate Level Simulation Protocol (ALSP), a protocol and supporting software that enables simulations to interoperate with one ano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregation (magazine)
''Aggregation'' was a Canadian online magazine published between 2010 and 2012. Each issue collected together stories and trends from five contributors based on hyperlinks they'd discover on the web. It was one of the first Canadian publications designed exclusively for Apple's iPad. ''Aggregation'' was conceived and published by Gary Campbell. It was released online, for free, on the 15th of the month for six consecutive months, from November 2010 to April 2011. After an eight-month hiatus, Campbell announced that a seventh issue was in the works. That issue was eventually published in August 2012 while Campbell was living in New York City. There has been no indication whether more issues are forthcoming. Each magazine cover featured a unique piece of interactive artwork by Campbell. The publication's design often took advantage of the multimedia nature of tablets by including touch-sensitive and video elements. Each issue's contributors were paid for their work through an hono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregation (linguistics)
In linguistics, aggregation is a subtask of natural language generation, which involves merging syntactic constituents (such as sentences and phrases) together. Sometimes aggregation can be done at a conceptual level. Examples A simple example of syntactic aggregation is merging the two sentences ''John went to the shop'' and ''John bought an apple'' into the single sentence ''John went to the shop and bought an apple''. Syntactic aggregation can be much more complex than this. For example, aggregation can embed one of the constituents in the other; e.g., we can aggregate ''John went to the shop'' and ''The shop was closed'' into the sentence ''John went to the shop, which was closed''. From a pragmatic perspective, aggregating sentences together often suggests to the reader that these sentences are related to each other. If this is not the case, the reader may be confused. For example, someone who reads ''John went to the shop and bought an apple'' may infer that the app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Aggregation
In molecular biology, protein aggregation is a phenomenon in which intrinsically-disordered or mis-folded proteins aggregate (i.e., accumulate and clump together) either intra- or extracellularly. Protein aggregates have been implicated in a wide variety of diseases known as amyloidoses, including ALS, Alzheimer's, Parkinson's and prion disease. After synthesis, proteins typically fold into a particular three-dimensional conformation that is the most thermodynamically favorable: their native state. This folding process is driven by the hydrophobic effect: a tendency for hydrophobic (water-fearing) portions of the protein to shield themselves from the hydrophilic (water-loving) environment of the cell by burying into the interior of the protein. Thus, the exterior of a protein is typically hydrophilic, whereas the interior is typically hydrophobic. Protein structures are stabilized by non-covalent interactions and disulfide bonds between two cysteine residues. The non-coval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω ''pheroo'' ('I carry') and ὁρμων ''hormon'' ('stimulating'). Pheromones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overdispersion
In statistics, overdispersion is the presence of greater variability ( statistical dispersion) in a data set than would be expected based on a given statistical model. A common task in applied statistics is choosing a parametric model to fit a given set of empirical observations. This necessitates an assessment of the fit of the chosen model. It is usually possible to choose the model parameters in such a way that the theoretical population mean of the model is approximately equal to the sample mean. However, especially for simple models with few parameters, theoretical predictions may not match empirical observations for higher moments. When the observed variance is higher than the variance of a theoretical model, overdispersion has occurred. Conversely, underdispersion means that there was less variation in the data than predicted. Overdispersion is a very common feature in applied data analysis because in practice, populations are frequently heterogeneous (non-uniform) c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flocculation
Flocculation, in the field of chemistry, is a process by which colloidal particles come out of suspension to sediment under the form of floc or flake, either spontaneously or due to the addition of a clarifying agent. The action differs from precipitation in that, prior to flocculation, colloids are merely suspended, under the form of a stable dispersion (where the internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation) and are not truly dissolved in solution. Coagulation and flocculation are important processes in water treatment with coagulation aimed to destabilize and aggregate particles through chemical interactions between the coagulant and colloids, and flocculation to sediment the destabilized particles by causing their aggregation into floc. Term definition According to the IUPAC definition, flocculation is "a process of contact and adhesion whereby the particles of a dispersion form larger-size clusters". Flocculatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Aggregation
Particle agglomeration refers to formation of assemblages in a suspension and represents a mechanism leading to the functional destabilization of colloidal systems. During this process, particles dispersed in the liquid phase stick to each other, and spontaneously form irregular particle assemblages, flocs, or agglomerates. This phenomenon is also referred to as coagulation or flocculation and such a suspension is also called ''unstable''. Particle agglomeration can be induced by adding salts or other chemicals referred to as coagulant or flocculant.M. Elimelech, J. Gregory, X. Jia, R. Williams, ''Particle Deposition and Aggregation: Measurement, Modelling and Simulation'', Butterworth-Heinemann, 1998. Particle agglomeration can be a reversible or irreversible process. Particle agglomerates defined as "hard agglomerates" are more difficult to redisperse to the initial single particles. In the course of agglomeration, the agglomerates will grow in size, and as a consequence they m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
