All articles A–Z

Simulations Plus

Simulations Plus, Inc. is an American biosimulation company incorporated in California in 1996, best known for the GastroPlus pharmacokinetic software platform; it was taken private by Altaris in 2026.

Simulator qualification (FAA)

Simulator qualification is the FAA's process of certifying flight simulators under 14 CFR Part 60 so pilots can earn training credit in a device rather than an aircraft.

SIMULIA

SIMULIA is the simulation software brand of the French company Dassault Systèmes, created in 2005 after acquiring ABAQUS, offering virtual testing of product performance and safety before physical prototypes.

Oct 21, 2026

Simuliidae

Simuliidae, commonly called black flies or buffalo gnats, is a family of small blood-feeding flies whose larvae develop in flowing freshwater; females transmit river blindness.

Simulink

Simulink is a block diagram environment for modeling, simulating, and deploying multidomain dynamic systems, developed by MathWorks as part of the MATLAB family and central to Model-Based Design.

Oct 22, 2026

Simulizi za Wanyama

Simulizi za Wanyama are Swahili animal tales in which talking animal characters teach lessons, best known through the trickster hare Sungura and the greedy hyena Fisi.

Simultaneous distillation extraction

Simultaneous distillation extraction (SDE) is a laboratory technique that isolates volatile compounds by combining steam distillation with continuous solvent extraction in one step, developed in 1964.

Simultaneous equations model

A simultaneous equations model is a statistical model in which several dependent variables are determined jointly, as when price and quantity determine each other in a market.

Simultaneous inference

Simultaneous inference is the family of statistical methods for testing several hypotheses in one analysis while controlling an overall error rate, such as the family-wise error rate.

Simultaneous iterative reconstructive technique

The simultaneous iterative reconstructive technique (SIRT) is an iterative algebraic algorithm for reconstructing images from projections, proposed by Gilbert in 1972, that uses all projection views in each update.

Simultaneous liver-kidney transplantation

Simultaneous liver-kidney transplantation (SLKT) is a single operation replacing both a failing liver and failing kidneys, accounting for roughly 10% of US liver transplants, a share that grew over 400% after MELD-based allocation began in 2002.

Simultaneous localization and mapping

Simultaneous localization and mapping, also known as concurrent mapping and localization or SLAM, is the computational problem of building a map of an unknown environment while tracking a robot's position within it.

Simultaneous machine translation

Simultaneous machine translation, also known as SiMT or real-time translation, is the task of translating a sentence from partial input before the speaker finishes, trading some quality for lower latency.

Simultaneous multithreading

Simultaneous multithreading (SMT), also called chip-level multithreading, is a processor design technique that lets several hardware threads issue instructions in the same cycle, filling idle execution slots.

Simultaneous nitrification-denitrification

Simultaneous nitrification-denitrification (SND) is a biological wastewater treatment process in which aerobic nitrification and anoxic denitrification proceed in one reactor, converting ammonium to nitrogen gas while cutting aeration energy and reactor footprint.

Simultaneous perturbation stochastic approximation

Simultaneous perturbation stochastic approximation (SPSA) is a stochastic optimization algorithm introduced by James C. Spall in 1992 that needs only two function evaluations per iteration.

Simultaneous resection

Simultaneous resection is a surgical strategy in which a primary bowel tumor and its liver metastases, most often colorectal cancer, are removed in a single operation under one general anesthetic rather than in two staged procedures.

Simultaneous saccharification and fermentation

Simultaneous saccharification and fermentation (SSF) is a biofuel process in which cellulose is broken down by enzymes and fermented to ethanol in a single reactor.

Simultaneous thermal analysis

Simultaneous thermal analysis (STA) applies two or more thermal analysis techniques, usually TGA and DSC or DTA, to the same sample at the same time.

Simultaneous transmitting and reflecting surface

A simultaneous transmitting and reflecting surface (STAR-RIS), also called an intelligent omni-surface, is a reconfigurable intelligent surface that splits wireless signals into transmitted and reflected parts, giving 360-degree coverage.

Oct 22, 2026

Simunhak

Simunhak (시문학) was a Korean monthly poetry magazine launched in March 1930 by Park Yong-cheol, the organ of the pure lyric poetry school Simunhakpa that ran three issues until October 1931.

Simurgh (سیمرغ)

Simurgh (سیمرغ), also Sēnmurw, is the mythical bird of Persian mythology: Avestan bird Saēna, Sasanian dog-headed composite, guardian of Zal in the Shahnameh, and Attar's thirty-birds metaphor for God in The Conference of the Birds.

Sep 19, 2026

Simurrum

Simurrum was an ancient kingdom in the Zagros foothills, centered on the Shahrizor plain in Iraqi Kurdistan, an adversary of the Ur III state under King Šulgi.

Simvastatin

Simvastatin, sold as Zocor, is a statin drug developed by Merck and approved in 1991 that lowers LDL cholesterol by blocking HMG-CoA reductase, the enzyme behind cholesterol synthesis.

Sin

Sin is moral evil considered from a religious standpoint, classically a deliberate violation of the will of God, with traditions differing on its origin and removal.

Sin (mythology)

Sin (Nanna, Su'en) is the Mesopotamian moon god, tutelary deity of Ur with the number 30 and the crescent emblem, father of Shamash and Ishtar, later venerated by Nabonidus at Harran.

Sin (song)

Sin (song): chiefly "Sin" by Nine Inch Nails, Halo 4 single from Pretty Hate Machine (1990, TVT), remixed by Sherwood and LeBlanc with Queen's Get Down Make Love; also MADKID's SIN, Shield Hero S3 opening theme.

Sin After Sin

Sin After Sin is the third studio album by the heavy metal band Judas Priest, released on CBS in 1977 and their first for a major label.