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Coffin lock

Coffin Lock is a slang term for a blind panel connector (also called a Butt-Joint Fastener) often used in performing arts to join together stage decks or scenery in a butt joint or cabinet and lid locks on road cases. These are typically two part connectors (male and female) that draw together and lock. The two most common types are the cam and acceptor (sold under the trade name “Roto-Lock”) and more traditional hook and pin version. These devices generally use an Allen key to operate the locking mechanism via a small diameter hole either through the face or rear of the panel. When locked, the considerable mechanical advantage offered by the cam or hook holds the panels tightly together. Coffin locks can be installed directly into a mortise cut into each panel, for total concealment except for the locking hole, or mounted to the rear of the panels.

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Fobney Lock

Fobney Lock is a lock on the River Kennet in the Small Mead area of Reading in the English county of Berkshire.

Fobney Lock was built between 1718 and 1723 under the supervision of the engineer John Hore of Newbury, and this stretch of the river is now administered by British Waterways and known as the Kennet Navigation. It has a rise/fall of 7 ft 8 in (2.24 m).<ref> </ref>

There have been ongoing plans to turn Fobney Island, adjacent to the lock, into a wetlands nature reserve.<ref></ref>


References

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See also

  • Locks on the Kennet and Avon Canal

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Bingley Five Rise Locks

Bingley Five Rise Locks is a staircase lock on the Leeds and Liverpool Canal at Bingley (). As the name implies, a boat going up the lock is lifted in five stages.


Description

In effect the 5-rise consists of five locks connected together with (as always with a staircase) no intermediate “pounds”: the lower gate of each chamber forms the upper gate of the chamber below. There are therefore five chambers, and six gates (the top and bottom gates and four intermediate gates). As the Leeds Liverpool canal is a wide canal, the chambers are 14 feet wide, and each “gate” consists of two half-gates, “hinged” from opposite sides of the canal. Each half gate is slightly more than 7 feet wide, so that the two halves close in a “V” shape (pointing “upstream”). Water pressure on the “uphill” side of the gate thus keeps it tightly closed until the water levels on either side are equal, when the gate can be opened and the boat moved to the next chamber (see canal locks for more information on how a lock is constructed and operated).

The 5-rise is the steepest flight of lock in the UK, with a gradient of about 1:5 (a rise of 59ft 2in over a distance of 320ft). The intermediate and bottom gates are the tallest in the country. Because of the complications of working a staircase lock, and because so many boaters (both first-time hirers and new owners) are inexperienced, a full-time lock keeper is employed, and the locks are padlocked “out of hours”. Barry Whitelock, the “locky”, after twenty years based here is now almost infamous on the local canals. Barry was awarded an MBE (Member of the Order of the British Empire) in the 2006 New Year Honours List for “Services to Inland Waterways in the North”<ref></ref>


History

It opened on March 21 1774 and was a major feat of engineering at the time. When the locks and therefore the canal from Gargrave to Leeds was opened in 1774 a crowd of 30,000 people turned out to celebrate it! The first boat to use the locks took just 28 minutes and the whole first trip is described here as it was in a newspaper of the time - the Leeds Intelligencer. The smaller Three Rise opened at the same time just a few hundred meters further down.

During 2000-2004, famous Leeds Chartered Surveyor, Gerwyn Bryan, lived in the famous cottage looking down on the locks, which appears in many pictures of the locks.


Tourism

The “flight” (it is a moot point whether a staircase is strictly a “flight”, used strictly the term means a group of locks separated by intermediate pounds, so each lock has its own top and bottom gates) is a major tourist attraction in the area. Most boats that pass through attract a lot of attention especially at weekends where they may be a crowd of thirty people or more watching a boat go up or down!


Maintenance

The staircase underwent extensive restorative maintenance in 2004,and again in 2006 when the lock gates and paddles were replaced. As is expected with such a feat of engineering it requires a lot of maintenance and is often on British Waterway’s list of winter stoppages for maintenance.


References


External links

  • Skipton Web: Five Rise Locks
  • Pennine Waterways

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Multiple granularity locking

In computer science, multiple granularity locking (MGL), sometimes called the John Rayner locking method, is a locking method used in database management systems (DBMS) and relational databases.

In MGL, locks are set on objects that contain other objects. MGL exploits the hierarchical nature of the contains relationship. For example, a database may have files, which contain pages, which further contain records. This can be thought of as a tree of objects, where each node contains its children. A lock locks a node and its descendants.

Multiple granularity locking is usually used with Non-strict two-phase locking to guarantee serializability. MGL uses lock escalation to determine granularity lock on a node and its ancestors.


Lock Modes

In addition to shared (S) locks and exclusive (X) locks from other locking schemes, like Strict two-phase locking, MGL also uses intention shared and intention exclusive locks. IS locks conflict with X locks, while IX locks conflict with S and X locks. The null lock (NL) is compatible with everything.

To lock a node in S (or X), MGL has the transaction locks all of its ancestors with IS (or IX), so if a transaction locks a node in S (or X), no other transaction can access its ancestors in X (or S and X).

MGL locking modes are compatible with each other as defined in the following matrix.

Mode NL IS IX S SIX EX
NL
IS
IX
S
SIX
EX

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Édouard Lock

Édouard Lock (born March 3, 1954) is a Canadian dance choreographer and the founder of the Canadian dance group, La La La Human Steps.

In 2001, he was made a Knight of the National Order of Quebec and an Officer of the Order of Canada. In 2006, he was made a Fellow of the Royal Society of Canada. [1]


External links

  • Édouard Lock at The Canadian Encyclopedia

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FinTS

FinTS or Financial Transaction Services is the successor of the German online banking standard HBCI. The FinTS-specification is publicly available on the ZKA website.
Features are:

  • Support for online-banking using PIN/TAN.
  • Support for online-banking with SWIFT.
  • Key stored on floppy-disk or chip-card for physical security.
  • Making use of XML and SOAP for data-exchange, encryption and signatures.
  • Implemented on top of Http, Https and SMTP as communication layer.


External links

  • FinTS - Financial Transaction Services

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Diffusing update algorithm

DUAL stands for Diffusing Update ALgorithm and is the algorithm used by EIGRP to calculate and create routing tables based on certain criteria.

DUAL is used to ensure a path to a network and provide a loopless routing environment. In order to help ensure delivery of a packet to a network, DUAL sends out query packets to its adjacent neighbors, or directly connected routers. As query packets are sent out, each router continues to forward the query packet until a router responds with a reply packet that has information on how to reach the specific network. When the reply packets are received by the router that sent out the query packets, DUAL calculates which route will be the successor and feasible successor.</br>
The successor is the main route. It is the shortest, most efficient route to a network that DUAL can find. The route to the successor router is calculated using delay, bandwidth, and other factors. The feasible successor is the backup route. The router that is the feasible successor has the second-best route to the network. It is not necessary for EIGRP to have a feasible successor.
</br>
When the successor or feasible successor goes down, DUAL sends out query packets to each router, and places the route in its routing table as “active.” When the route is active, DUAL is recalculating the path to the new network. Once it is calculated, the route is marked as “passive,” and normal network operation can resume.</br></br>


External links

  • The DUAL Algorithm

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Conservative two-phase locking

In computer science, conservative two-phase locking (C2PL) is a locking method used in DBMS and relational databases.

Conservative 2PL prevents deadlocks.

The difference between 2PL and C2PL is that C2PL’s transactions obtain all the locks they need before the transactions begin. This is to ensure that a transaction that already holds some locks will not block waiting for other locks.

In heavy lock contention, C2PL reduces the time locks are held on average, relative to 2PL and Strict 2PL, because transactions that hold locks are never blocked.

In light lock contention, C2PL holds more locks than is necessary, because it is hard to tell what locks will be needed in the future, thus leads to higher overhead.

Also, a transaction will not even obtain any locks if it cannot obtain all the locks it needs in its initial request. Furthermore, each transaction needs to declare its read and write set (data items to be read/written during transaction), which is not always possible. Because of these limitations, C2PL is not used very frequently.

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TPMS

TPMS can stand for any of the following:

  • Takoma Park Middle School, located in Silver Spring, Maryland
  • Tyre Pressure Monitoring System, a safety device made to alert automobile operators when their tires are under inflated
  • Transaction Processing Management System, a transaction processing monitor from ICL
  • Triply-Periodic Minimal Surface, an unbounded minimal surface that is periodic in three dimensions.

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Vectored I/O

Vectored I/O, also known as scatter/gather I/O, is method of input and output by which a single procedure call sequentially writes data from multiple buffers to a single data stream or reads data from a data stream to multiple buffers. The buffers are given in a vector of buffers. Scatter/gather refers to the process of gathering data from, or scattering data into, the given set of buffers. The I/O can be performed synchronously or asynchronously. The main reasons for using vectored I/O are efficiency and convenience.

There are several usages for vectored I/O:

  • Atomicity: If the particular vectored I/O implementation supports atomicity, a process can write from or read into a set of buffers to or from a file without risk that another thread or process might perform I/O on the same file between the first process’ reads or writes, thereby corrupting the file or compromising the integrity of the input;
  • Concatenating output: An application that wants to write non-sequentially placed data in memory can do so in one vectored I/O operation. For example, writing a fixed-size header and its associated payload data that are placed non-sequentially in memory can be done by a single vectored I/O operation without first concatenating the header and the payload to another buffer;
  • Efficiency: One vectored I/O read or write can replace many ordinary reads or writes, and thus save on the overhead involved in syscalls;
  • Splitting input: When reading data that are in a format that defines a fixed-size header, one can use a vector of buffers in which the first buffer is the size of that header; and the second buffer will contain the data associated with the header.

The applicable functions readv<ref>readv in FreeBSD 6.2 Reference Library</ref> and writev<ref>writev in FreeBSD 6.2 Reference Library</ref> can be found in POSIX 1003.1-2001, 4.2BSD, 4.4BSD, FreeBSD 6.2, and the Single UNIX Specification version 2. The Windows API has analogous functions ReadFileScatter and WriteFileGather; however unlike the POSIX functions they require each buffer to be aligned on a memory page.<ref>ReadFileScatter in MSDN Library</ref> Windows Sockets provide separate WSASend and WSARecv functions without this requirement.


References

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Central locking

  1. redirect: power door locks

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Ribble Link

The Ribble Link is Great Britain’s newest inland waterway, opened in 2002. The four-mile link connects the once-isolated Lancaster Canal with the main navigable system via a canalisation of the Savick Brook which is tidal in its lower reaches. The Link runs around the outskirts of Preston and flows into the River Ribble. From there it uses the River Douglas to connect with the Leeds and Liverpool Canal’s Rufford Branch.

The channel has been widened to allow navigation by 10 ft 6 in beam boats. Starting from the Lancaster Canal, the Ribble Link descends about 59 feet (18 metres) by means of:

  • a staircase of three locks
  • four conventional locks
  • one lock which is semi-tidal at its lower end
  • a rotating sector gate (originally planned as a lock) only passable around high tide.


Closure

The Ribble Link was indefinitely closed during 2006 with British Waterways citing that the appearance of voids meant that the last section was too dangerous to operate for both British Waterways staff and boaters.<ref>British Waterways notice posted at Johnson Hillock Locks, Whittle Springs 2006</ref>. After dredging and infilling behing lock chambers during the winter of 2006-7, the link was re-opened on 6 April 2007.


See also

  • Canals of Great Britain
  • History of the British canal system


References

<references />


External links

  • Map sources:

    • - junction with the Lancaster Canal
    • - the Savick Brook joining the Ribble
  • Ribble Link Trust

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Kris Jamsa

Kris Jamsa is an author of computer science books. Jamsa received a bachelor’s degree in computer science from the United States Air Force Academy. He also. received a master’s degree in computer science from Las Vegas University of Nevada, a doctoral degree from Arizona State University, an MBA from San Diego State University, and a master’s degree in Education from Aspen University.

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Caversham Lock

Caversham Lock is a lock and weir situated on the River Thames in Reading, Berkshire, England. Caversham Lock includes a somewhat larger than normal lock island, also known as De Bohun Island, separating the lock from the weir.

The lock, weir and island is owned and managed by the Environment Agency. Besides a typical lock-keeper’s house, the island until recently contained a boat yard and boat house used by the Environment Agency’s river patrol and maintenance services. At the time of writing (December 1, 2004), controversial proposals to redevelop the island and some adjoining land as a hotel are under discussion.


Access to and across the lock

A public access exists across the lock gates, lock island and weir, forming a pedestrian route from the centre of Reading to the Lower Caversham area of the cross-river suburb of Caversham.


Reach above the lock

The river passes though the built up area of Reading under Reading Bridge and Caversham Bridge. The north bank passes through the suburb of Caversham before reaching open meadows, while on the south bank is Tilehurst and later Purley-on-Thames. The Thames Path follows the south bank to Mapledurham lock.


See also

  • Locks on the River Thames
  • Crossings of the River Thames
  • Islands in the River Thames


External links

  • Caversham Life, Living and Community

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WS-Transaction

A Web Services specification developed by BEA Systems, International Business Machines Corporation, and Microsoft Corporation. The WS-Transaction specification describes coordination types that are used with the extensible coordination framework described in the WS-Coordination specification. It defines two coordination types: Atomic Transaction (AT) for individual operations, and Business Activity (BA) for long running transactions. Developers can use either or both of these coordination types when building applications that require consistent agreement on the outcome of distributed activities.


External links

  • WS-Transaction specification

Distributed transactions with WS-AtomicTransaction and JTA

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