21-letter words containing y, a, h
- nightmare file system — Pejorative hackerism for Sun's Network File System (NFS). In any nontrivial network of Suns where there is a lot of NFS cross-mounting, when one Sun goes down, the others often freeze up. Some machine tries to access the down one, and (getting no response) repeats indefinitely. This causes it to appear dead to some messages (what is actually happening is that it is locked up in what should have been a brief excursion to a higher spl level). Then another machine tries to reach either the down machine or the pseudo-down machine, and itself becomes pseudo-down. The first machine to discover the down one is now trying both to access the down one and to respond to the pseudo-down one, so it is even harder to reach. This situation snowballs very quickly, and soon the entire network of machines is frozen - worst of all, the user can't even abort the file access that started the problem! Many of NFS's problems are excused by partisans as being an inevitable result of its statelessness, which is held to be a great feature (critics, of course, call it a great misfeature). ITS partisans are apt to cite this as proof of Unix's alleged bogosity; ITS had a working NFS-like shared file system with none of these problems in the early 1970s. See also broadcast storm.
- north atlantic treaty — the treaty (1949) signed by 12 countries, providing for the establishment of NATO.
- one-way hash function — (algorithm) (Or "message digest function") A one-way function which takes a variable-length message and produces a fixed-length hash. Given the hash it is computationally infeasible to find a message with that hash; in fact one can't determine any usable information about a message with that hash, not even a single bit. For some one-way hash functions it's also computationally impossible to determine two messages which produce the same hash. A one-way hash function can be private or public, just like an encryption function. MD5, SHA and Snefru are examples of public one-way hash functions. A public one-way hash function can be used to speed up a public-key digital signature system. Rather than sign a long message, which can take a long time, compute the one-way hash of the message, and sign the hash.
- open graphics library — (graphics, library) (OpenGL) A multi-platform software interface to graphics hardware, supporting rendering and imaging operations. The OpenGL interface was developed by Silicon Graphics, who license it to other vendors. The OpenGL graphics interface consists of several hundred functions operating on 2D and 3D objects, supporting basic techniques, such as modelling and smooth shading, and advanced techniques, such as texture mapping and motion blur. Many operations require a frame buffer. OpenGL is network-transparent, and a common extension to the X Window System allows an OpenGL client to communicate across a network with a different vendor's OpenGL server. OpenGL is based on Silicon Graphics' proprietary IRIS GL.
- orthogonal trajectory — the locus of a point whose path cuts each curve of a family of curves at right angles.
- otorhinolaryngologist — (medicine) Doctor specializing in otorhinolaryngology, the study of ear, nose, and throat.
- pacific daylight time — the version of Pacific Standard Time that is in use when daylight saving time is being observed
- pellitory-of-the-wall — an urticaceous plant, P. diffusa, of the S and W European genus Parietaria, which grows in crevices and has long narrow leaves and small pink flowers
- pentamethylenediamine — cadaverine.
- physical anthropology — the branch of anthropology dealing with the evolutionary changes in human anatomy and physiology, using mensurational and descriptive techniques.
- physically challenged — See example at challenged (def 1).
- physician's assistant — a person trained to perform under the supervision of a physician many clinical procedures traditionally performed by a physician, as diagnosing and treating minor ailments. Abbreviation: PA.
- play with a full deck — Nautical. a floorlike surface wholly or partially occupying one level of a hull, superstructure, or deckhouse, generally cambered, and often serving as a member for strengthening the structure of a vessel. the space between such a surface and the next such surface above: Our stateroom was on B deck.
- pneumoencephalography — encephalography.
- polygenic inheritance — the heredity of complex characters that are determined by a large number of genes, each one usually having a relatively small effect.
- potassium thiocyanate — a colorless, crystalline, hygroscopic, water-soluble solid, KSCN, used chiefly in the manufacture of chemicals, dyes, and drugs.
- primary sex character — any of the body structures directly concerned in reproduction, as the testes, ovaries, and external genitalia.
- privacy enhanced mail —
- psychological primary — one of a set of perceived colours (red, yellow, blue, green, black, and white) that can be used to characterize all other perceived colours
- psychological warfare — the use of propaganda, threats, and other psychological techniques to mislead, intimidate, demoralize, or otherwise influence the thinking or behavior of an opponent.
- psychomotor agitation — agitation (def 3).
- psychomotor-agitation — the act or process of agitating; state of being agitated: She left in great agitation.
- psychopathic disorder — (in England, according to the Mental Health Act 1983) a persistent disorder or disability of mind which results in abnormally aggressive or seriously irresponsible conduct on the part of the person concerned
- psychopharmacotherapy — the use of psychoactive drugs in the symptomatic treatment or control of mental disorders or psychiatric disease.
- pulse height analyser — a multichannel analyser that sorts pulses into selected amplitude ranges
- pulse height analyzer — an instrument that records or counts an electrical pulse if its amplitude falls within specified limits: used in nuclear physics research for the determination of energy spectra of nuclear radiations
- put in the hard yards — to make a great effort to achieve an end
- rayleigh distribution — (mathematics) A curve that yields a good approximation to the actual labour curves on software projects.
- rectangular hyperbola — a hyperbola with perpendicular asymptotes
- reinforcement therapy — a behavior modification technique in which appropriate behavior is strengthened through systematic reinforcement.
- reverse polish syntax — postfix notation
- ring-around-the-rosey — a children's game in which the players sing while going around in a circle and squat when the lyrics “all fall down” are sung.
- saint anthony's cross — tau cross.
- salam-weinberg theory — the electroweak theory.
- schlieren photography — a type of photography which records schlieren
- scholastic philosophy — the system of philosophy, theology, and teaching that dominated medieval western Europe and was based on the writings of the Church Fathers and (from the 12th century) Aristotle, the Greek philosopher (384–322 bc)
- scorched earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- scorched-earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- seventh day adventist — Seventh Day Adventist churches are churches that believe that Jesus Christ will return very soon, and that have Saturday as their holy day.
- seventh-day adventist — See example at Seventh-Day.
- snappy video snapshot — (hardware) (registered trademark) A frame grabber for the IBM PC designed and marketed by Play, Inc..
- strachey, christopher — Christopher Strachey
- structural psychology — psychology centering on the analysis of the structure or content of conscious mental states by introspective methods.
- sunday school teacher — someone who teaches at a Sunday school
- sympathetic vibration — a vibration induced by resonance.
- symphonie fantastique — a programmatic symphony (1830–31) in five movements by Hector Berlioz.
- synchrotron radiation — electromagnetic radiation emitted by charged particles as they pass through magnetic fields.
- take sb/sth seriously — If you take someone or something seriously, you believe that they are important and deserve attention.
- tartarian honeysuckle — an Asian honeysuckle, Lonicera tatarica, having fragrant, white to pink flowers.
- the apple of your eye — If you say that someone is the apple of your eye, you mean that they are very important to you and you are extremely fond of them.