omniomni/omni-engineering huggingface dataset:
HP 33s. The HP 33s (F2216A) was a scientific calculator marketed by Hewlett-Packard. It was introduced in 2003 as the successor to the HP 32SII, and discontinued on the introduction of its successor the HP 35s in 2007.

Features
Its main features are:
 RPN or traditional semi-algebraic (infix data/algebraic operator entry/postfix one-number function entry), user-selectable
 Two-line LCD display
 Full scientific/engineering mathematical features
 Keystroke-programmable with full boolean and program-control command sets and line edit, insert and delete
 HP "equation list" equation editor (fully algebraic) in both the stand-alone list as well as in keystroke programs
 HP Solver feature (solves equations and functions for one unknown)
 Function integration feature
 All mathematical operations and features fully functional in all modes
 Unit conversion and constants
 31 KB of random-access user memory (equivalent to about 7 KB on earlier HP programmable models)

The main differences from the HP 32SII are:
 A radical difference in keypad layout and appearance
 Memory is expanded from 2 KB to 32 KB
 Faster processor
 More functions
 Algebraic entry mode as well as RPN
 The display has two lines
 The length of an equation was now restricted to 255 characters (no arbitrary limit in the 32SII)

The HP 33s was co-designed and manufactured by Kinpo Electronics of Taiwan.

Reception
The 33s is generally considered to have fewer logic bugs than the HP 35s. However, the unconventional chevron-styled keypad has been regarded by reviewers as bizarre and difficult to use compared to other HP professional calculators.

Revisions
The 33s went through numerous revisions that have solved two of the most pervasive issues people had with the early models (namely poor screen quality and bad keypad responsiveness).

See also
 List of Hewlett-Packard products: Pocket calculators
 HP calculators

References

External links
 
 
 

33s
PBR. PBR may refer to:

Science and technology
 Pusey-Barrett-Rudolph theorem about the reality of quantum states

Computing, electronics, electrics
 Partition boot record, of a computer hard drive
 Passive bistatic radar
 Pebble-bed reactor, a type of nuclear fission reactor
 Physically based rendering, a method used in computer graphics
 Policy-based routing, in computer networking

Chemistry, biochemistry
 Packed Bed Reactor, in chemical processing
 Peripheral benzodiazepine receptor, another name for translocator protein
 Phosphorus bromide (PBr)
 Photobioreactor

Geology
 Periodic Bedrock Ridges
 Precariously balanced rock, another name for a balancing rock

Business, Commerce
 Payment by Results
 Performance-based regulation of utilities
 Petrobras (NYSE stock ticker code PBR), Brazilian oil company
 Plant breeders' rights over new varieties
 Pre-Budget Report, one of the two economic forecasts that HM Treasury is required to deliver to the UK Parliament each year
 Price-to-book ratio, ratio of a company's stock price to its book value

Military
 Patrol Boat, River, a US Navy designation
 Plastic baton round, a type of non-lethal projectile

Transport
 Potters Bar railway station (National Rail station code PBR), Hertfordshire, England, UK
 Puffing Billy Railway, tourist railway in Melbourne, Australia

Other
 Pabst Blue Ribbon, an American beer brand
 Parti Burkinabè pour la Refondation, Burkina Faso political party
 Pelita Bandung Raya, a football club based in Bandung, Indonesia
 Professional Bull Riders, an international professional bull riding organization

See also

 
 PBRS
 Pontypool and Blaenavon Railway (P&BR), South Wales, UK
Local Security Authority Subsystem Service. Local Security Authority Subsystem Service (LSASS) is a process in Microsoft Windows operating systems that is responsible for enforcing the security policy on the system.  It verifies users logging on to a Windows computer or server, handles password changes, and creates access tokens. It also writes to the Windows Security Log.

Forcible termination of  will result in the system losing access to any account, including NT AUTHORITY, prompting a restart of the machine. Because,  is a crucial system file, its name is often faked by malware. The  file used by Windows is located in the directory , and the description of the file is Local Security Authority Process. If it is running from any other location, that  is most likely a virus, spyware, trojan or worm. Due to the way some systems display fonts, malicious developers may name the file something like  (capital "i" instead of a lowercase "L") in efforts to trick users into installing or executing a malicious file instead of the trusted system file. The Sasser worm spreads by exploiting a buffer overflow in the LSASS on Windows XP and Windows 2000 operating systems.

References

External links
Security Subsystem Architecture
LSA Authentication
MS identity management

Microsoft Windows security technology
Windows NT architecture
Access control software
Windows components
Formatting Objects Processor. Formatting Objects Processor (FOP, also known as Apache FOP) is a Java application that converts XSL Formatting Objects (XSL-FO) files to PDF or other printable formats.
FOP was originally developed by James Tauber who donated it to the Apache Software Foundation in 1999. It is part of the Apache XML Graphics project.

FOP is open source software, and is distributed under the Apache License 2.0.

Current status
The latest version of Apache FOP is 2.9. This is the eleventh stable release.

Major limitations
Most important elements added in XSL-FO 1.1 (flow maps, table markers, indexes. etc.) are not available 

In addition, older XSL-FO 1.0 features are still not fully supported including automatic table layout, floats and more.

Input support
Apache FOP supports embedding a number of image formats in the XSL-FO (through the <fo:external-graphic> element). These include:

 SVG
 PNG
 Bitmap BMP
 PostScript (as EPS)
 JPEG
 Some TIFF formats.

Apache FOP implements the <fo:float> element with some limitations. In versions prior to 2.0, external graphics objects were limited to being drawn inline or in a block with no wrapped text.

Output formats
Apache FOP supports the following output formats:

 PDF (best output support), including PDF/X and PDF/A with some limitations
 ASCII text file facsimile
 PostScript
 Direct printer output (PCL)
 AFP
 RTF
 Java2D/AWT for display, printing, and page rendering to PNG and TIFF

In progress:
MIF
SVG

See also

 XSL Formatting Objects (XSL-FO)
 XSL

External links
 Apache FOP Project
 XSL-FO formatter comparison

References

FOP
Free system software
Free software programmed in Java (programming language)
Java (programming language) libraries
Enhanced Imaging System. Enhanced Imaging System (EIS), officially referred to as "Enhanced Imagery System", previously known as 8X, and sometimes unofficially known as Misty 2 and KH-13, is an American reconnaissance satellite program. A derivative of the Improved Crystal satellites, EIS replaced Misty, and was intended to provide more coverage and dwell time than previous reconnaissance satellites; like Misty, it has stealth capabilities. Only one EIS satellite has been launched; USA-144, which was placed into orbit by a Titan IVB rocket on 22 May 1999.

History
In 1995, a Los Angeles Times article reported that the 8X program was intended as "a major upgrade to the KH-12", with a mass of as much as 20 tons, which would be used for detailed imaging with a wide field of view. The cost of the program was a subject of disagreement from some within the military at the time. By 1998, the program had been renamed Enhanced Imaging System. The Future Imagery Architecture program, which was intended to replace the Lacrosse and Improved Crystal satellites, was developed alongside EIS.

See also
Corona series: KH-1, KH-2, KH-3, KH-4
KH-5 ARGON, KH-6 LANYARD
KH-7 and KH-8 GAMBIT
KH-9 HEXAGON "Big Bird"
Manned Orbital Laboratory (MOL) or KH-10
KH-11

References

Further reading
John Pike (July 24, 1998). 8X Enhanced Imaging System.  Federation of American Scientists. Accessed May 3, 2004 (October 17, 2001).
US space-based reconnaissance reinforced.  Jane's Defence Weekly.  Accessed May 3, 2004.

Reconnaissance satellites of the United States
Military equipment introduced in the 1990s
Turnbuckle. A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a conventional right-hand thread and the other with a left-hand thread. The tension can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables.

Uses
Turnbuckles are most commonly used in applications which require a great deal of tension; they can range in mass from about  for thin cable used in a garden fence, to tonnes for structural elements in buildings and suspension bridges.

Aircraft
Turnbuckles have been used in aircraft construction, especially during the early years of aviation. Historically, biplanes might use turnbuckles to adjust the tension on structural wires bracing their wings. Turnbuckles are also widely used on flexible cables in flight control systems. In both cases they are secured with lockwire or specifically designed wire clips to prevent them from turning and losing tension due to vibration.

Shipping
Turnbuckles are used for tensioning a ship's rigging and lashings. A variant of the turnbuckle called a bottle screw features an enclosed tubular body.

Entertainment industry
Turnbuckles are used in nearly all rigging performed in the entertainment industry, including theatre, film, and live concert performances. In entertainment rigging, turnbuckles are more commonly used to make small adjustments in line lengths. This is generally to make a flown (hoisted) unit sit parallel to the stage. Another way a turnbuckle could prove helpful is with making very minor height or angle adjustments.

Pipe systems
Turnbuckles are used in piping systems as a way to provide minor adjustments for field inconsistencies. This also allows for a minimum amount of resistance when transferring the load to the support components.

Orthopaedics
A type of splint is used for upper limb to produce gradual stretching over contracted joint by its turn buckle mechanism. Used to treat stiff elbow and Volkmann Ischemic Contracture.

Gallery

See also
 Buffers and chain coupler
 Guy-wire
 Mechanical joint

References

External links
 

Hardware (mechanical)
Sailing rigs and rigging
Ring (martial arts)
UAV ground control station. UAV ground control station (GCS) is a land- or sea-based control centre that provides the facilities for human control of Unmanned Aerial Vehicles (UAVs or "drones"). It may also refer to a system for controlling rockets within or above the atmosphere, but this is typically  described as a Mission Control Centre.

Hardware 

GCS hardware refers to the complete set of ground-based hardware systems used to control the UAV. This typically includes the Human-Machine Interface, computer, telemetry, video capture card and aerials for the control, video and data links to the UAV.

Fixed Installation and Vehicle Mounted GCS 

Larger military UAVs such as the General Atomics MQ-1 Predator feature what resembles a "virtual cockpit". The pilot or sensor operator sits in front of a number of screens showing the view from the UAV, a map screen and aircraft instrumentation. Control is through a conventional aircraft-style joystick and throttle, possibly with Hands on Throttle and Stick (HOTAS) functionality.

In addition, the GCS consists of satellite or long-range communication links that are mounted on the roof or on a separate vehicle, container or building.

Portable GCS 

Smaller UAVs can be operated with a traditional "twin-stick" style transmitter, as used for radio controlled model aircraft. Extending this setup with a laptop or tablet computer, data and video telemetry, and aerials, creates what is effectively a Ground Control Station.

A number of suppliers offer a combined system that consists of what looks like a modified transmitter combined with what is usually a touch screen. An internal computer running the GCS software sits behind the screen, along with the video and data links.

Larger GCS units are also available that typically fit inside flight cases. As with the smaller units, they feature an internal computer running the GCS software, along with video and data links. Large single or dual screens are also fitted that can be high-brightness or treated with an anti-glare coating to increase visibility in bright sunlight. They can either be placed on the ground, on a portable table, or feature integrated folding legs.

Some portable GCS units are in the HOTAS (Hands On Throttle And Stick) layout. This layout includes a 3-Axis Joystick to control yaw, pitch and roll of the UAV. A slide or t-bar fader can increase or decrease the airspeed of the UAV.

Software 
GCS software is typically run on a ground-based computer that is used for planning and flying a mission. It provides a map screen where the user can define waypoints for the flight, and see the progress of the mission. It also serves as a “virtual cockpit”, showing many of the same instruments as in manned aircraft.

See also
Unmanned aerial vehicle
Shadow 200 TUAV
Mission control centre
Rocket launch
Unmanned aircraft system

References

Military aviation
Christmas tree packet. In information technology, a Christmas tree packet (also known as a kamikaze packet, nastygram, or lamp test segment) is a network message segment or packet with every option enabled for the particular network protocol in use.

Background
Network packets contain a number of flags or options depending on the type of network protocol in use.  Enabling options can elicit specific behaviors in the device receiving the packet and differences in the responses to the packets. By analyzing those differences, Christmas tree packets can be used as a method of TCP/IP stack fingerprinting, exposing the underlying nature of a TCP/IP stack by sending the packets and then awaiting and analyzing the responses. When used as part of scanning a system, the TCP header of a Christmas tree packet has the flags FIN, URG and PSH set. Many operating systems implement their compliance with the Internet Protocol standards in varying or incomplete ways.  By observing how a host responds to an odd packet, such as a Christmas tree packet, inferences can be made regarding the host's operating system.  Versions of Microsoft Windows, BSD/OS, HP-UX, Cisco IOS, MVS, and IRIX display behaviors that differ from the RFC standard when queried with said packets. 

A large number of Christmas tree packets can also be used to conduct a DoS attack by exploiting the fact that Christmas tree packets require much more processing by routers and end-hosts than the "usual" packets do.

Christmas tree packets can be easily detected by intrusion-detection systems or more advanced firewalls. From a network security point of view, Christmas tree packets are always suspicious and indicate a high probability of network reconnaissance activities.

See also 
Martian packet

References

External links
Nmap documentation

Computer jargon
Packets (information technology)
Denial-of-service attacks
Bookend. A bookend is an object tall, sturdy, and heavy enough that is placed at either end of a row of upright books to support or buttress them.   Heavy bookends—made of wood, bronze, marble, and even large geodes—have been used in libraries, stores, and homes for centuries; the simple sheetmetal bookend (originally patented in 1877 by William Stebbins Barnard) uses the weight of the books standing on its foot to clamp the bookend's tall brace against the last book's back; in libraries, simple metal brackets are often used to support the end of a row of books. Elaborate and decorative bookends are common as elements in home decor.

The word "bookend" is also used metaphorically to refer to any pair of items which frame and define a significant or noteworthy event or place. For example, regarding the practice in the United States whereby Memorial Day and Labor Day demarcate the traditional beginning and end of summer, those two holidays could be referred to as bookends. Bookends are usually made of metal and plastic.

See also 
 Bookend terrace, a bookend effect in the design of terraced houses.

References

External links

 Bookend sizes
 The History of Bookends

Book terminology
FR-4. FR-4 (or FR4) is a NEMA grade designation for glass-reinforced epoxy laminate material. FR-4 is a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant (self-extinguishing).

"FR" stands for "flame retardant", and does not denote that the material complies  with the standard UL94V-0 unless testing is performed to UL 94, Vertical Flame testing in Section 8 at a compliant lab. The designation FR-4 was created by NEMA in 1968.

FR-4 glass epoxy is a popular and versatile high-pressure thermoset plastic laminate grade with good strength to weight ratios. With near zero water absorption, FR-4 is most commonly used as an electrical insulator possessing considerable mechanical strength. The material is known to retain its high mechanical values and electrical insulating qualities in both dry and humid conditions. These attributes, along with good fabrication characteristics, lend utility to this grade for a wide variety of electrical and mechanical applications.

Grade designations for glass epoxy laminates are: G-10, G-11, FR-4, FR-5 and FR-6. Of these, FR-4 is the grade most widely in use today. G-10, the predecessor to FR-4, lacks FR-4's self-extinguishing flammability characteristics. Hence, FR-4 has since replaced G-10 in most applications.

FR-4 epoxy resin systems typically employ bromine, a halogen, to facilitate flame-resistant properties in FR-4 glass epoxy laminates. Some applications where thermal destruction of the material is a desirable trait will still use G-10 non flame resistant.

Properties 
Which materials fall into the "FR-4" category is defined in the NEMA LI 1-1998 standard. Typical physical and electrical properties of FR-4 are as follows. The abbreviations LW (lengthwise, warp yarn direction) and CW (crosswise, fill yarn direction) refer to the conventional perpendicular fiber orientations in the XY plane of the board (in-plane). In terms of Cartesian coordinates, lengthwise is along the x-axis, crosswise is along the y-axis, and the z-axis is referred to as the through-plane direction. The values shown below are an example of a certain manufacturer's material. Another manufacturer's material will usually have slightly  different values. Checking the actual values, for any particular material, from the manufacturer's datasheet, can be very important, for example in high frequency applications.

where:
 LW Lengthwise
 CW Crosswise
 PF Perpendicular to laminate face

Applications 

FR-4 is a common material for printed circuit boards (PCBs). A thin layer of copper foil is typically laminated to one or both sides of an FR-4 glass epoxy panel. These are commonly referred to as copper clad laminates. The copper thickness or copper weight can vary and so is specified separately. 

FR-4 is also used in the construction of relays, switches, standoffs, busbars, washers, arc shields, transformers and screw terminal strips.

See also
FR-2
Polyimide
G-10 (material)

References

Further reading
 

Printed circuit board manufacturing
Fibre-reinforced polymers
Dissipation factor. In physics, the dissipation factor (DF) is a measure of loss-rate of energy of a mode of oscillation (mechanical, electrical, or electromechanical) in a dissipative system.  It is the reciprocal of quality factor, which represents the "quality" or durability of oscillation.

Explanation
Electrical potential energy is dissipated in all dielectric materials, usually in the form of heat.  In a capacitor made of a dielectric placed between conductors, the typical lumped element model includes a lossless ideal capacitor in series with a resistor termed the equivalent series resistance (ESR) as shown below.  The ESR represents losses in the capacitor.  In a good capacitor the ESR is very small, and in a poor capacitor the ESR is large. However, ESR is sometimes a minimum value to be required.  Note that the ESR is not simply the resistance that would be measured across a capacitor by an ohmmeter.  The ESR is a derived quantity with physical origins in both the dielectric's conduction electrons and dipole relaxation phenomena.  In dielectric only one of either the conduction electrons or the dipole relaxation typically dominates loss.  For the case of the conduction electrons being the dominant loss, then

 

where

  is the dielectric's bulk conductivity,
  is the lossless permittivity of the dielectric, and
  is the angular frequency of the AC current i,
  is the lossless capacitance.

If the capacitor is used in an AC circuit, the dissipation factor due to the non-ideal capacitor is expressed as the ratio of the resistive power loss in the ESR to the reactive power oscillating in the capacitor, or

 

When representing the electrical circuit parameters as vectors in a complex plane, known as phasors, a capacitor's dissipation factor is equal to the tangent of the angle between the capacitor's impedance vector and the negative reactive axis, as shown in the adjacent diagram.  This gives rise to the parameter known as the loss tangent tan δ where

 

Alternatively,  can be derived from frequency at which loss tangent was determined and capacitance

 

Since the  in a good capacitor is usually small, , and  is often expressed as a percentage. 

 approximates to the power factor when  is far less than , which is usually the case.

 will vary depending on the dielectric material and the frequency of the electrical signals.  In low dielectric constant (low-κ), temperature compensating ceramics,  of 0.1–0.2% is typical.  In high dielectric constant ceramics,  can be 1–2%.  However, lower  is usually an indication of quality capacitors when comparing similar dielectric material.

See also
 Dielectric withstand test
 Impulse generator

References

Electromagnetism
Electrical engineering
Dynamical systems