Notice that two "ones" can't appear together, and the maximum number of zeros in a row is three. This bit stream is then NRZI encoded to be written to disk, a 1 bit representing a magnetic transition, and a 0 bit no transition. Example: 1 0 1 0 0 0 0 1 ($A1) 0100010010101001 ($44A9) 0100010010001001 ($4489 - sync mark) ^ missing clock Hexadecimal 4489 is typically used as a unique synchronization mark. ...

See also:

Modified Frequency Modulation, Modified Frequency Modulation - Coding

Read more here: » Modified Frequency Modulation: Encyclopedia II - Modified Frequency Modulation - Coding

Memory modules added RAM main memory to the calculator, allowing more programming steps and/or more data registers. The original HP-41C had a main memory of 63 registers of 7 bytes each. Each register could hold either a number, a 6-character string, or up to 7 program steps in the Focal language (program steps used a variable number of bytes). Each memory module added 64 registers, and the calculator could hold up to 4 of them, for a grand total of 319 registers. While this was considered huge for the time (a little more than ...

See also:

HP-41 extension module, HP-41 extension module - The Memory Modules HP-41C only, HP-41 extension module - The Application Pacs, HP-41 extension module - The 82104A Card Reader, HP-41 extension module - The 82182A Time Module, HP-41 extension module - The 82143A Thermal Printer/Plotter, HP-41 extension module - The 82153A Optical Wand, HP-41 extension module - The 82180A Extended Functions Module, HP-41 extension module - The 82181A Extended Memory Module, HP-41 extension module - The HP82160A HP Interface Loop HP-IL module

Read more here: » HP-41 extension module: Encyclopedia II - HP-41 extension module - The Memory Modules HP-41C only

The first rectangular QAM constellation usually encountered is 16-QAM, the constellation diagram for which is shown here. A Gray coded bit-assignment is also given. The reason that 16-QAM is usually the first is that a brief consideration reveals that 2-QAM and 4-QAM are in fact binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK), respectively. 8-QAM presents problems in dividing an odd number of bits between the tw ...

See also:

Quadrature amplitude modulation, Quadrature amplitude modulation - Overview, Quadrature amplitude modulation - Ideal structure, Quadrature amplitude modulation - Transmitter, Quadrature amplitude modulation - Receiver, Quadrature amplitude modulation - Performance, Quadrature amplitude modulation - Definitions, Quadrature amplitude modulation - Rectangular QAM, Quadrature amplitude modulation - Odd-k QAM, Quadrature amplitude modulation - Non-rectangular QAM

Read more here: » Quadrature amplitude modulation: Encyclopedia II - Quadrature amplitude modulation - Rectangular QAM

Two diagrams of circular QAM constellation are shown, for 8-QAM and 16-QAM. The circular 8-QAM constellation is known to be the optimal 8-QAM constellation in the sense of requiring the least mean power for a given minimum Euclidean distance. The 16-QAM constellation is suboptimal although the optimal one may be constructed along the same lines as the 8-QAM constellation. The circular constellation highlights the relationship between QAM and PSK. Other orders of constellation may be constructed along similar (or very different!) lines. It is ...

See also:

Quadrature amplitude modulation, Quadrature amplitude modulation - Overview, Quadrature amplitude modulation - Ideal structure, Quadrature amplitude modulation - Transmitter, Quadrature amplitude modulation - Receiver, Quadrature amplitude modulation - Performance, Quadrature amplitude modulation - Definitions, Quadrature amplitude modulation - Rectangular QAM, Quadrature amplitude modulation - Odd-k QAM, Quadrature amplitude modulation - Non-rectangular QAM

Read more here: » Quadrature amplitude modulation: Encyclopedia II - Quadrature amplitude modulation - Non-rectangular QAM

Internal to the laboratory are racks, rack standoffs, and vestibule jumpers. The lab racks house the system hardware in removable modular units. The rack standoffs provide a volume for ducting, piping and wiring to be run to/from the individual racks and throughout the Lab. The racks interface to the piping and wiring in the standoff via outlets and ports located in the standoffs at the base end of each rack location. Jumpers in the vestibule, the area between Unity and Destiny, connect the piping and wiring between the two. Grounding ...

See also:

Destiny Laboratory Module, Destiny Laboratory Module - Destiny’s Laboratory Structure, Destiny Laboratory Module - Specifications, Destiny Laboratory Module - Reference

Read more here: » Destiny Laboratory Module: Encyclopedia II - Destiny Laboratory Module - Destiny’s Laboratory Structure

The card reader was a device able to read and write small rectangular plastic cards with two magnetic strips. The card reader could copy contents of memory onto magnetic cards, and later read back the data into memory. As the HP-41C had permanent memory (user programs and data were not wiped out when power was off) there was no absolute need for a permanent storage device, so the card reader was optional. Each card held two strips of 112 bytes each, that could hold 16 data registers or up to 112 program steps. This limited capa ...

See also:

HP-41 extension module, HP-41 extension module - The Memory Modules HP-41C only, HP-41 extension module - The Application Pacs, HP-41 extension module - The 82104A Card Reader, HP-41 extension module - The 82182A Time Module, HP-41 extension module - The 82143A Thermal Printer/Plotter, HP-41 extension module - The 82153A Optical Wand, HP-41 extension module - The 82180A Extended Functions Module, HP-41 extension module - The 82181A Extended Memory Module, HP-41 extension module - The HP82160A HP Interface Loop HP-IL module

Read more here: » HP-41 extension module: Encyclopedia II - HP-41 extension module - The 82104A Card Reader

Although the SERMs have no immediate structural relationship with 17β-estradiol, they are stereochemically similar to this estrogen. There are three types of estrogen receptors, which are intracellular: α (α homodimer), β (β homodimer) and αβ (α- and β-receptor heterodimer). Different tissues have more or less of each class. In turn, each SERM has more affinity to one and less to the other estrogen receptor isoform. The α-receptor is generally stimulatory, but the β-receptor may ...

See also:

Selective estrogen receptor modulator, Selective estrogen receptor modulator - Members, Selective estrogen receptor modulator - Uses, Selective estrogen receptor modulator - Method of action, Selective estrogen receptor modulator - Actions

Read more here: » Selective estrogen receptor modulator: Encyclopedia II - Selective estrogen receptor modulator - Method of action

SERMs are used dependent on their pattern of action in various tissues: clomifene is used in anovulation raloxifene is used for osteoporosis and is being studied as a breast cancer preventative tamoxifen and toremifene are used for breast cancer Some SERMs may be good replacements for hormone replacement therapy (HRT), which has recently been discredited, although the above agents still have an unacceptably high risk of ...

See also:

Selective estrogen receptor modulator, Selective estrogen receptor modulator - Members, Selective estrogen receptor modulator - Uses, Selective estrogen receptor modulator - Method of action, Selective estrogen receptor modulator - Actions

Read more here: » Selective estrogen receptor modulator: Encyclopedia II - Selective estrogen receptor modulator - Uses

Quadrature amplitude modulation - Transmitter. The following picture shows the ideal structure of a QAM transmitter: First the flow of bits to be transmitted is split into two equal parts: this process generates two independent signals to be transmitted. They are encoded separately just like they were in an ASK modulator. Then one channel (the one "in phase") is multiplied by a cosine, while the other channel ("in quadrature") is multiplied by a sine. This way there is a phase of 90° between them. They are simply added one to the other and sent through the real channel.

See also:

Quadrature amplitude modulation, Quadrature amplitude modulation - Overview, Quadrature amplitude modulation - Ideal structure, Quadrature amplitude modulation - Transmitter, Quadrature amplitude modulation - Receiver, Quadrature amplitude modulation - Performance, Quadrature amplitude modulation - Definitions, Quadrature amplitude modulation - Rectangular QAM, Quadrature amplitude modulation - Odd-k QAM, Quadrature amplitude modulation - Non-rectangular QAM

Read more here: » Quadrature amplitude modulation: Encyclopedia II - Quadrature amplitude modulation - Ideal structure

The isomorphism theorems are also valid for modules over a fixed ring R (and therefore also for vector spaces over a fixed field). One has to replace the term "group" by "R-module", "subgroup" and "normal subgroup" by "submodule", and "factor group" by "factor module". The isomorphism theorems are also valid for rings, ring homomorphisms and ideals. One has to replace the term "group" by "ring", "subgroup" and "normal s ...

See also:

Isomorphism theorem, Isomorphism theorem - Groups, Isomorphism theorem - First isomorphism theorem, Isomorphism theorem - Second isomorphism theorem also known as the third isomorphism theorem, Isomorphism theorem - Third isomorphism theorem also known as the second isomorphism theorem, Isomorphism theorem - Rings and modules, Isomorphism theorem - General

Read more here: » Isomorphism theorem: Encyclopedia II - Isomorphism theorem - Rings and modules

The printer used rolls of thermal paper to print lines of up to 24 characters. The thermal paper provided for a bluish printout, but was somewhat unstable, as the printout could vanish or the whole paper turn blue due to excessive heat. The printer had some graphical capabilities, as you could design your own character shapes, or even turn on or off individual pixels. However, the buffer memory could not hold sufficient information to print a whole line in graphic mode, and you could not alter line spacing, so it was impossible to print continuous graphics. The printer nevertheless provided s ...

See also:

HP-41 extension module, HP-41 extension module - The Memory Modules HP-41C only, HP-41 extension module - The Application Pacs, HP-41 extension module - The 82104A Card Reader, HP-41 extension module - The 82182A Time Module, HP-41 extension module - The 82143A Thermal Printer/Plotter, HP-41 extension module - The 82153A Optical Wand, HP-41 extension module - The 82180A Extended Functions Module, HP-41 extension module - The 82181A Extended Memory Module, HP-41 extension module - The HP82160A HP Interface Loop HP-IL module

Read more here: » HP-41 extension module: Encyclopedia II - HP-41 extension module - The 82143A Thermal Printer/Plotter

PCM was invented by the British engineer Alec Reeves in 1937 while working for the International Telephone and Telegraph in France. The first transmission of speech by pulse code modulation was the SIGSALY voice encryption equipment used for high-level Allied communications during World War II from 1943. ...

See also:

Pulse-code modulation, Pulse-code modulation - Digitization as part of the PCM process, Pulse-code modulation - Encoding the bitstream as a signal, Pulse-code modulation - History of PCM

Read more here: » Pulse-code modulation: Encyclopedia II - Pulse-code modulation - History of PCM

Pulse-code modulation can be either return-to-zero (RZ) or non-return-to-zero (NRZ). For a NRZ system to be synchronized using in-band information, there must not be long sequences of identical symbols, such as ones or zeroes. For binary PCM systems, the density of 1-symbols is called 'ones-density'. Ones-density is often controlled using precoding techniques such as Run Length Limited encoding, where the PCM code is expanded into a slightly longer code with a guaranteed bound on ones-density before modulation into the channel. In other cases, extra 'framing' bits are a ...

See also:

Pulse-code modulation, Pulse-code modulation - Digitization as part of the PCM process, Pulse-code modulation - Encoding the bitstream as a signal, Pulse-code modulation - History of PCM

Read more here: » Pulse-code modulation: Encyclopedia II - Pulse-code modulation - Encoding the bitstream as a signal

In conventional PCM, the analog signal may be processed (e.g. by amplitude compression) before being digitized. Once the signal is digitized, the PCM signal is not subjected to further processing (e.g. digital data compression). Some forms of PCM combine signal processing with coding. Older versions of these systems applied the processing in the analog domain as part of the A/D process, newer implementations do so in the digital domain. These simple techniques have been largely rendered obsolete by modern transform-based signal compre ...

See also:

Pulse-code modulation, Pulse-code modulation - Digitization as part of the PCM process, Pulse-code modulation - Encoding the bitstream as a signal, Pulse-code modulation - History of PCM

Read more here: » Pulse-code modulation: Encyclopedia II - Pulse-code modulation - Digitization as part of the PCM process

The Lunar Module was the portion of the Apollo spacecraft that landed on the moon and returned to lunar orbit. It is divided into two major parts, the Descent Module and the Ascent Module. It was designed specifically for flight in space. It supplied life support systems for two astronauts for a total of four to five days. The spacecraft was designed and manufactured by the Grumman Aircraft Company led by Tom Kelly. The Descent Module contains the landing gear, landing radar antenna, descent rocket engine, and fuel to land on the moon ...

See also:

Apollo spacecraft, Apollo spacecraft - Launch Escape System LES, Apollo spacecraft - Command Module CM, Apollo spacecraft - Service Module SM, Apollo spacecraft - Lunar Module LM, Apollo spacecraft - Spacecraft Lunar Module Adapter SLA, Apollo spacecraft - Abort modes

Read more here: » Apollo spacecraft: Encyclopedia II - Apollo spacecraft - Lunar Module LM

The Mir space station was constructed by connecting several Mir modules, each launched into orbit separately by the Proton rocket, except for the Docking Module, which was brought to Mir by the Space Shuttle. Mir - Core Module. The Core Module provided living quarters and station control. It was equipped with six docking ports, and it served as a core of the multi-modular space station. It was launched on February 19, 1986 at 21:28 UTC from Baikonur LC200 with a Proton 8K82K. Its initi ...

See also:

Mir, Mir - History, Mir - Mir modules, Mir - Core Module, Mir - Kvant-1, Mir - Kvant-2, Mir - Kristall, Mir - Spektr, Mir - Docking Module, Mir - Priroda, Mir - Names, Mir - International cooperation, Mir - Mir in popular culture, Mir - Expeditions spacewalks and crews

Read more here: » Mir: Encyclopedia II - Mir - Mir modules

The Service Module was a portion of the spacecraft that is unpressurized and contains fuel cells, batteries, high gain antenna, radiators, water, oxygen, hydrogen, reaction control system, propellant to enter and leave lunar orbit, and service propulsion system. On Apollo 15, 16 and 17 it also carried a scientific instrument package, mapping camera and a small sub-satellite to study the moon. A major portion of the service module is taken up by propellant and the main rocket engine that placed the Apollo spacecraft into and out of lun ...

See also:

Apollo spacecraft, Apollo spacecraft - Launch Escape System LES, Apollo spacecraft - Command Module CM, Apollo spacecraft - Service Module SM, Apollo spacecraft - Lunar Module LM, Apollo spacecraft - Spacecraft Lunar Module Adapter SLA, Apollo spacecraft - Abort modes

Read more here: » Apollo spacecraft: Encyclopedia II - Apollo spacecraft - Service Module SM

As well as the core application (for modeling, texturing, lighting and rendering), CINEMA 4D also has several add-on programs available that expand its capabilites. These programs include: Advanced Render (global illumination/HDRI, caustics, ambient occlusion and sky simulation) BodyPaint 3D (direct painting on UVW meshes) Dynamics (for simulating soft body and rigid body dynamics) HAIR (simulates hair, fur, grass, etc.) MOCCA (character animation and cloth simulation) NET Render (to ...

See also:

Cinema 4D, Cinema 4D - Overview, Cinema 4D - Modules, Cinema 4D - Program History

Read more here: » Cinema 4D: Encyclopedia II - Cinema 4D - Modules

Main articles: 8VSB, 256QAM ATSC signals are designed to use the same 6 MHz bandwidth as NTSC television channels. Once the video signals have been compressed, the data stream can be modulated in a variety of manners depending on the method of transmission. Terrestrial (local) broadcasters use a 8-VSB modulation that can transfer at a maximum rate of 19.39 Mbit/s, sufficient to carry several video channels and metadata depending on conditions. Cable television operators generally have a higher signal-to-noise ratio and can use 16-VSB or 256-QAM to achieve ...

See also:

ATSC, ATSC - Resolution, ATSC - Codecs, ATSC - Modulation and Transmission, ATSC - Design flaws

Read more here: » ATSC: Encyclopedia II - ATSC - Modulation and Transmission

Except for a few early limited edition modules, all modules of early Dungeons & Dragons were denoted with a code consisting of a letter and a number. Modules within a letter set were usually somehow related, either thematically or as a series of linked adventures. For example, Z1 may be a prologue to Z2. Or Z1, Z2 and Z3 may have the adventurers fighting a similar enemy such as beholders. Though related, most modules were stand-alone and ...

See also:

Adventure Dungeons & Dragons, Adventure Dungeons & Dragons - History of official modules and adventures, Adventure Dungeons & Dragons - Contents of Adventures, Adventure Dungeons & Dragons - Module Codes

Read more here: » Adventure Dungeons & Dragons: Encyclopedia II - Adventure Dungeons & Dragons - Module Codes

At the start of each UTC second, the WWVB 60 kHz carrier, which has a normal power of 50 kW, is reduced in power by 17 dB. Before July 12, 2005, the power reduction was 10 dB. The type of bit transmitted on each second is determined by when the carrier wave is returned to normal power within that second. If the carrier power is returned to normal in one-fifth of a second, or 0.2 s, from when it was reduced, the bit is a zero. If the carrier power is returned to normal in one half-second, or 0.5 s, the bit is a one. If the carrier power is re ...

See also:

WWVB, WWVB - Antennas, WWVB - Modulation Format, WWVB - Propagation, WWVB - Antenna Reuse with former WWVL

Read more here: » WWVB: Encyclopedia II - WWVB - Modulation Format

The Spacecraft Lunar Module Adapter (SLA) is an aluminum cone shaped structure that connects the Service Module to the Saturn S-IVB rocket stage. It also protects the Lunar Module during launch and ascent through the atmosphere. It is made up of four large panels that open from the top similar to flower petals. The SLA is made from 42.5 mm thick aluminum honeycomb material. The exterior of the SLA is covered by a layer of cork nearly 1 mm thick and then painted white. The cork insulates the Lunar Mod ...

See also:

Apollo spacecraft, Apollo spacecraft - Launch Escape System LES, Apollo spacecraft - Command Module CM, Apollo spacecraft - Service Module SM, Apollo spacecraft - Lunar Module LM, Apollo spacecraft - Spacecraft Lunar Module Adapter SLA, Apollo spacecraft - Abort modes

Read more here: » Apollo spacecraft: Encyclopedia II - Apollo spacecraft - Spacecraft Lunar Module Adapter SLA