All articles starting with P
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Prefabricated vertical drains
A prefabricated vertical drain (PVD), also called a wick drain or band drain, is a geosynthetic strip driven through soft clay to shorten drainage paths and accelerate consolidation under embankment preloads.
Prefabrication
Prefabrication, also called prefabricated construction, is a construction method in which components are manufactured under controlled conditions, then transported and assembled on site, as in immersed tube tunnels.
Preface to the Sacred Teachings
The Preface to the Sacred Teachings (Da Tang Sanzang Shengjiao Xu, 大唐三藏圣教序) is a preface by Emperor Taizong of Tang honoring Xuanzang's Buddhist translations, best known as an 672 stele assembled from Wang Xizhi's calligraphy.
PRefChem
PRefChem (Pengerang Refining and Petrochemical) is the name for two joint ventures of PETRONAS and Saudi Aramco operating a 300,000-barrel-per-day refinery and petrochemical complex in Pengerang, Johor, Malaysia, started up in 2019.
Prefect
Prefect (Latin praefectus, "one set in charge"): a senior official governing an administrative division for a central power. Roman praefecti, the Napoleonic French department prefect, and modern prefects in Italy, Romania, and Ukraine.
Prefecture
Prefecture: an administrative division headed by a prefect, from Latin praefectura. Covers France's state-appointed departmental prefects (1800), Japan's 47 self-governing todofuken (1871, Local Autonomy Law 1947), China's prefecture-level tier, and Greece's abolished 1833-2010 prefectures.
Préfecture de Siguiri
Siguiri Prefecture (Préfecture de Siguiri), Guinea's northeastern Kankan-region prefecture on the Malian border; chief town Siguiri-Centre; Guinea's most populous prefecture and center of industrial (AngloGold Ashanti) and artisanal gold mining.
Prefecture of Chenzhou
Prefecture of Chenzhou (郴州地区) was a prefecture of Hunan, China, 1970–1994, seat at county-level Chenzhou City, administering 2 cities and 9 counties before its abolition by Guo Han [1994] No. 136, which created prefecture-level Chenzhou City.
Prefecture System Law
The Prefecture System Law (府県制, Fukensei) was a Japanese law promulgated on May 17, 1890, that structured prefectural government with elected assemblies and executive councils, and was fully revised in 1899.
Prefecture-level city (地级市)
Prefecture-level city (地级市), dijishi: a second-level Chinese administrative division between provinces and counties, typically a central urban core plus rural counties. 293 exist among 333 prefecture-level divisions; created by the 1983 city-leading-counties reform.
Prefectures of Japan
Prefectures of Japan (todōfuken, 都道府県): the 47 first-tier local governments, one metropolis (Tokyo), one district (Hokkaidō), two urban prefectures (Kyoto, Osaka), and rural prefectures, created in 1871.
Preference elicitation
Preference elicitation is the set of methods for turning a person's choices and trade-offs into a formal preference representation, such as utility-function parameters or attribute weights.
Preference learning
Preference learning is the branch of machine learning that models preferences from comparative data like ratings and rankings, spanning rank aggregation, recommender systems, and RLHF for aligning language models.
Preference optimization
Preference optimization is a family of fine-tuning methods that aligns language models with human preferences by training on paired judgments of candidate outputs rather than reward models.
Preference test
A preference test is a behavioral paradigm that measures a person's or animal's selection or engagement with options to infer preference, a core tool in applied behavior analysis and animal welfare science.
Preference utilitarianism
Preference utilitarianism, also called desire utilitarianism, is a variety of utilitarianism holding that good lies in fulfilling people's preferences, associated with R. M. Hare and Peter Singer.
Preferential attachment
Preferential attachment is a network growth rule where new links attach to already well-connected vertices, explaining the scale-free structure of citation networks and the web.
Preferential enrichment
Preferential enrichment (PE) is a symmetry-breaking enantiomeric resolution phenomenon, reported in 1998 by Rui Tamura's group, in which simple recrystallization of racemic mixed crystals enriches one enantiomer in the mother liquor.
Preferential flow
Preferential flow is the movement of water and solutes through a small fraction of the pore network, such as roots, burrows, and cracks, bypassing most of the soil matrix.
Preferential looking
Preferential looking is an experimental paradigm that infers what infants and animals can perceive by measuring which of two visual stimuli they look at longer.
Preferential solvation
Preferential solvation is the enrichment or depletion of one component of a solvent mixture in the solvation shell around a solute, compared with its bulk concentration.
Preferential voting in national elections by country
Preferential voting in national elections is the use of ranked ballots in countries such as Australia, Ireland, and Malta, electing national chambers by alternative vote or single transferable vote.
Preferred habitat theory
Preferred habitat theory is a term-structure theory holding that bond investors have preferred maturity ranges and must be offered a premium to hold bonds outside them.
Preferred IUPAC name
A preferred IUPAC name, or PIN, is the single name chosen by IUPAC rules from among the valid names for a chemical structure, introduced in 2013.
Preferred Networks
Preferred Networks, also known as PFN, is a Tokyo deep-learning company founded in 2014 by Toru Nishikawa and Daisuke Okanohara, known for the PLaMo AI models and MN-Core chips.
Preferred prime minister opinion polling for the next United Kingdom general election
Preferred prime minister polling for the next UK general election: YouGov head-to-heads and Ipsos open questions on who would be best PM, showing Andy Burnham leading Farage, Badenoch, Polanski, and Davey in 2026, with methodology and historical benchmarks.
Preferred Reporting Items for Systematic Reviews and Meta-Analyses
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) is a reporting guideline with a 27-item checklist and flow diagram for transparently reporting systematic reviews and meta-analyses in health research.
Preferred stock
Preferred stock, also known as preference shares, is equity paying a fixed dividend that ranks ahead of common stock but behind bonds, typically with no maturity or voting rights.
Preferred walking speed
Preferred walking speed (PWS), also called self-selected or comfortable walking speed, is the pace a person chooses spontaneously when walking, about 1.4 m/s in healthy adults, and a standard measure in gait analysis and geriatric assessment.
Prefetching (computing)
Prefetching is a computer architecture technique in which data or instructions are fetched into a cache before the processor requests them, hiding memory latency. It is done by hardware or software.