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Aggregation
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 Aus ... [...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 ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link Aggregation
In computer networking, link aggregation is the combining ( aggregating) of multiple network connections in parallel by any of several methods, in order to increase throughput beyond what a single connection could sustain, to provide redundancy in case one of the links should fail, or both. A link aggregation group (LAG) is the combined collection of physical ports. Other umbrella terms used to describe the concept include trunking, bundling, bonding, channeling or teaming. Implementation may follow vendor-independent standards such as Link Aggregation Control Protocol (LACP) for Ethernet, defined in IEEE 802.1AX or the previous IEEE 802.3ad, but also proprietary protocols. Motivation Link aggregation increases the bandwidth and resilience of Ethernet connections. Bandwidth requirements do not scale linearly. Ethernet bandwidths historically have increased tenfold each generation: 10 megabit/s, 100 Mbit/s, 1000 Mbit/s, 10,000 Mbit/s. If one started to bump in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Composition
In computer science, object composition and object aggregation are closely related ways to combine objects or data types into more complex ones. In conversation the distinction between composition and aggregation is often ignored. Common kinds of compositions are objects used in object-oriented programming, tagged unions, sets, sequences, and various graph structures. Object compositions relate to, but are not the same as, data structures. Object composition refers to the logical or conceptual structure of the information, not the implementation or physical data structure used to represent it. For example, a sequence differs from a set because (among other things) the order of the composed items matters for the former but not the latter. Data structures such as arrays, linked lists, hash tables, and many others can be used to implement either of them. Perhaps confusingly, some of the same terms are used for both data structures and composites. For example, "binary tree" ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Community Choice Aggregation
Community Choice Aggregation (CCA), also known as Community Choice Energy, municipal aggregation, governmental aggregation, electricity aggregation, and community aggregation, is an alternative to the investor owned utility energy supply system in which local entities in the United States aggregate the buying power of individual customers within a defined jurisdiction in order to secure alternative energy supply contracts. The CCA chooses the power generation source on behalf of the consumers. By aggregating purchasing power, they are able to create large contracts with generators, something individual buyers may be unable to do. The main goals of CCAs have been to either lower costs for consumers or to allow consumers greater control of their energy mix, mainly by offering "greener" generation portfolios than local utilities. Eight states in the United States have enacted CCA enabling law. They are: Massachusetts, Ohio, California, Illinois, New Jersey, New York, Rhode Island, and V ... [...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-covale ... [...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: ''activatio ... [...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] |
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 ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate Function
In database management, an aggregate function or aggregation function is a function where the values of multiple rows are grouped together to form a single summary value. Common aggregate functions include: * Average (i.e., arithmetic mean) * Count * Maximum * Median * Minimum * Mode * Range * Sum Others include: * Nanmean (mean ignoring NaN values, also known as "nil" or "null") * Stddev Formally, an aggregate function takes as input a set, a multiset (bag), or a list from some input domain and outputs an element of an output domain . The input and output domains may be the same, such as for SUM, or may be different, such as for COUNT. Aggregate functions occur commonly in numerous programming languages, in spreadsheets, and in relational algebra. The listagg function, as defined in the SQL:2016 standard aggregates data from multiple rows into a single concatenated string. Decomposable aggregate functions Aggregate functions present a bottleneck, because they poten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregation (ethology)
{{unreferenced, date=July 2013 In ethology, an aggregation is any form of gathering of organisms and the process of coming together. In some forms groups of unrelated species might form, in which interaction between members of the aggregation might be minimal; for example herds of grazing zebra and antelopes might combine, both the better to observe the approach of predators, and to improve the odds of escape in the event of attack by predators. Sometimes there might be some interaction, such as mixed flocks of birds that observe each other's foraging behaviour in searching for food. Sometimes there might be quite orderly common action, such as the queuing up for a resource; for example different species of fishes may aggregate around a cleaning station where cleaner wrasse and cleaner shrimp are active, more or less taking turns for attention. Such aggregations, where there is no particular association of species or sizes, may be referred to loosely as unstructured aggregations. ... [...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 signal, 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'). P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regional Television In Australia
In Australia, regional television is the local television services outside of the five main Australian cities (Sydney, Melbourne, Brisbane, Adelaide and Perth). History 1960s The first regional television stations were launched five years after the rollout of television to metropolitan Sydney, Melbourne, Brisbane, Adelaide and Perth. GLV-10 in Traralgon opened on 9 December 1961 and was followed 14 days later by GMV-6 in Shepparton and BCV-8 Bendigo. Television continued to expand throughout Victoria and the rest of the country throughout the 1960s with no fewer than twenty five stations making their first transmissions between 1962 and 1968. 1962 station openings *4 March: NBN-3 Newcastle *17 March: CBN-8 Orange *18 March: WIN-4 Wollongong *27 April: BTV-6 Ballarat *12 May: RTN-8 Lismore *26 May: TNT-9 Launceston *2 June: CTC-7 Canberra *13 July: DDQ-10 Toowoomba *1 November: TNQ-7 Townsville 1963 station opening *7 September: RTQ-7 Rockhampton 1964 station openi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
