Description.

The algorithm may informally be described as performing the following steps: In more detail, it may be implemented following the pseudocode below. As described above, the starting vertex for the algorithm will be chosen arbitrarily, because the first iteration of the main loop of the algorithm will have a set of vertices in "Q" that all have equal weights, and the algorithm will automatically start a new tree in "F" when it completes a spanning tree of each connected component of the input graph. The algorithm may be modified to start with any particular vertex "s" by setting "C"["s"] to be a number smaller than the other values of "C" (for instance, zero), and it may be modified to only find a single spanning tree rather than an entire spanning forest (matching more closely the informal description) by stopping whenever it encounters another vertex flagged as having no associated edge.  Different variations of the algorithm differ from each other in how the set "Q" is implemented: as a simple linked list or array of vertices, or as a more complicated priority queue data structure. This choice leads to differences in the time complexity of the algorithm. In general, a priority queue will be quicker at finding the vertex "v" with minimum cost, but will entail more expensive updates when the value of "C"["w"] changes.

Time complexity.

The time complexity of Prim's algorithm depends on the data structures used for the graph and for ordering the edges by weight, which can be done using a priority queue. The following table shows the typical choices:  A simple implementation of Prim's, using an adjacency matrix or an adjacency list graph representation and linearly searching an array of weights to find the minimum weight edge to add, requires O(<nowiki>|</nowiki>V<nowiki>|</nowiki>) running time. However, this running time can be greatly improved further by using heaps to implement finding minimum weight edges in the algorithm's inner loop.  A first improved version uses a heap to store all edges of the input graph, ordered by their weight. This leads to an O(|E| log |E|) worst-case running time. But storing vertices instead of edges can improve it still further. The heap should order the vertices by the smallest edge-weight that connects them to any vertex in the partially constructed minimum spanning tree (MST) (or infinity if no such edge exists). Every time a vertex "v" is chosen and added to the MST, a decrease-key operation is performed on all vertices "w" outside the partial MST such that "v" is connected to "w", setting the key to the minimum of its previous value and the edge cost of ("v","w").  Using a simple binary heap data structure, Prim's algorithm can now be shown to run in time O(<nowiki>|</nowiki>E<nowiki>|</nowiki> log <nowiki>|</nowiki>V<nowiki>|</nowiki>) where <nowiki>|</nowiki>E<nowiki>|</nowiki> is the number of edges and <nowiki>|</nowiki>V<nowiki>|</nowiki> is the number of vertices. Using a more sophisticated Fibonacci heap, this can be brought down to O(<nowiki>|</nowiki>E<nowiki>|</nowiki> + <nowiki>|</nowiki>V<nowiki>|</nowiki> log <nowiki>|</nowiki>V<nowiki>|</nowiki>), which is asymptotically faster when the graph is dense enough that <nowiki>|</nowiki>E<nowiki>|</nowiki> is ω(<nowiki>|</nowiki>V<nowiki>|</nowiki>), and linear time when |E| is at least |V| log |V|. For graphs of even greater density (having at least |V| edges for some "c" > 1), Prim's algorithm can be made to run in linear time even more simply, by using a "d"-ary heap in place of a Fibonacci heap.

Proof of correctness.

Let "P" be a connected, weighted graph. At every iteration of Prim's algorithm, an edge must be found that connects a vertex in a subgraph to a vertex outside the subgraph. Since "P" is connected, there will always be a path to every vertex. The output "Y" of Prim's algorithm is a tree, because the edge and vertex added to tree "Y" are connected. Let "Y" be a minimum spanning tree of graph P. If "Y"="Y" then "Y" is a minimum spanning tree. Otherwise, let "e" be the first edge added during the construction of tree "Y" that is not in tree "Y", and "V" be the set of vertices connected by the edges added before edge "e". Then one endpoint of edge "e" is in set "V" and the other is not. Since tree "Y" is a spanning tree of graph "P", there is a path in tree "Y" joining the two endpoints. As one travels along the path, one must encounter an edge "f" joining a vertex in set "V" to one that is not in set "V". Now, at the iteration when edge "e" was added to tree "Y", edge "f" could also have been added and it would be added instead of edge "e" if its weight was less than "e", and since edge "f" was not added, we conclude that  Let tree "Y" be the graph obtained by removing edge "f" from and adding edge "e" to tree "Y". It is easy to show that tree "Y" is connected, has the same number of edges as tree "Y", and the total weights of its edges is not larger than that of tree "Y", therefore it is also a minimum spanning tree of graph "P" and it contains edge "e" and all the edges added before it during the construction of set "V". Repeat the steps above and we will eventually obtain a minimum spanning tree of graph "P" that is identical to tree "Y". This shows "Y" is a minimum spanning tree. The minimum spanning tree allows for the first subset of the sub-region to be expanded into a smaller subset "X", which we assume to be the minimum.

Parallel algorithm.

The main loop of Prim's algorithm is inherently sequential and thus not parallelizable. However, the inner loop, which determines the next edge of minimum weight that does not form a cycle, can be parallelized by dividing the vertices and edges between the available processors. The following pseudocode demonstrates this.  This algorithm can generally be implemented on distributed machines as well as on shared memory machines. It has also been implemented on graphical processing units (GPUs). The running time is formula_2, assuming that the "reduce" and "broadcast" operations can be performed in formula_3. A variant of Prim's algorithm for shared memory machines, in which Prim's sequential algorithm is being run in parallel, starting from different vertices, has also been explored. It should, however, be noted that more sophisticated algorithms exist to solve the distributed minimum spanning tree problem in a more efficient manner.

In computer science, Prim's (also known as Jarník's) algorithm is a greedy algorithm that finds a minimum spanning tree for a weighted undirected graph. This means it finds a subset of the edges that forms a tree that includes every vertex, where the total weight of all the edges in the tree is minimized. The algorithm operates by building this tree one vertex at a time, from an arbitrary starting vertex, at each step adding the cheapest possible connection from the tree to another vertex.


Biography.

He was born at Brandenburg an der Havel, of a family of French Huguenot origin, as evidenced in his family name. His grandfather, Heinrich August de la Motte Fouqué, had been one of Frederick the Great's generals and his father was a Prussian officer. Although not originally intended for a military career, Friedrich de la Motte Fouqué ultimately gave up his university studies at Halle to join the army, and he took part in the Rhine campaign of 1794. The rest of his life was devoted mainly to literary pursuits. He was introduced to August Wilhelm Schlegel, who deeply influenced him as a poet ("mich gelehret Maß und Regel | Meister August Wilhelm Schlegel") and who published Fouqué's first book, "Dramatische Spiele von Pellegrin", in 1804.

Marriage.

Fouqué's first marriage was unhappy and soon ended in divorce. His second wife, Caroline Philippine von Briest (1773–1831), enjoyed some reputation as a novelist in her day. After her death Fouqué married a third time. Some consolation for the ebbing tide of popular favour was afforded him by the munificence of Frederick William IV of Prussia, who granted him a pension which allowed him to spend his later years in comfort. He died in Berlin in 1843.  For Fouqué's life see "Lebensgeschichte des Baron Friedrich de la Motte Fouqué (only to the year 1813), Aufgezeichnet durch ihn selbst" (Halle, 1840), and also the introduction to Koch's selections in the "Deutsche Nationalliteratur".

Literary work.

Romantic roots.

After "Dramatische Spiele von Pellegrin", his second work, "Romanzen vom Tal Ronceval" (1805), showed more plainly his allegiance to the romantic leaders, and in the "Historie vom edlen Ritter Galmy" (1806) he versified a 16th-century romance of medieval chivalry.  "Sigurd der Schlangentödter, ein Heldenspiel in sechs Abentheuren" (1808), was the first modern German dramatization of the Nibelung legend combining Icelandic sources such as the Volsunga Saga and the Middle High German Nibelungenlied. The play and its two sequels "Sigurds Rache" (1809) and "Aslaugas Ritter" (1810) were published together under the title "Der Held des Nordens" in 1810 ["The Hero of the North"]. The trilogy brought Fouqué to the attention of the public, and had a considerable influence on subsequent versions of the story, such as Friedrich Hebbel's "Nibelungen" and Richard Wagner's "Der Ring des Nibelungen".  These early writings indicate the lines which Fouqué's subsequent literary activity followed; his interests were divided between medieval chivalry on the one hand and northern mythology on the other. In 1813, the year of the rising against Napoleon, he again fought with the Prussian army, and the new patriotism awakened in the German people left its mark upon his writings.

Popular works.

Between 1810 and 1815, Fouqué's popularity was at its height; the many romances and novels, plays and epics which he produced with extraordinary rapidity, appealed greatly to the mood of the hour. "Undine" appeared around 1811, the only work by which Fouqué's memory still lives today. A more comprehensive idea of his talent may, however, be obtained from the two romances "Der Zauberring" (1813) and "Die Fahrten Thiodolfs des Isländers" (1815).

Later years.

From 1820 onwards the quality of Fouqué's work deteriorated, partly owing to the fatal formal ease with which he wrote, and he failed to keep pace with the changes in German taste by clinging to the paraphernalia of romanticism. His rivals applied a sobriquet of "Don Quixote of Romanticism" to him.

Translations.

Most of Fouqué's works have been translated. Menella Bute Smedley, for instance, translated his ballad, "The Shepherd of the Giant Mountains." The English versions of "Aslauga's Knight" (by Thomas Carlyle), "Sintram and his Companions" and "Undine" have been frequently republished.

Influence.

Fouqué's play "Der Sängerkrieg auf der Wartburg" (The Song Contest on the Wartburg) is likely one of the sources for Wagner's "Tannhäuser". Goethe was not impressed by it, remarking to Eckermann: "We both agreed that all his life this poet had engaged in old Germanic studies, however without being able to develop this into a culture of his own making." Robert Louis Stevenson admired Fouqué's story "The Bottle Imp" and wrote his own version ("The Bottle Imp") with a Hawaiian setting. John Henry Newman and Charlotte Mary Yonge both praised "Sintram and his Companions". William Morris also became an admirer of "Sintram and his Companions", and it influenced Morris' own fiction. "Sintram and his Companions" and "Undine" are referred to in "Little Women" by Louisa May Alcott; the character Jo mentions wanting them for Christmas in the first chapter of the book and finally receives them in chapter 22. "Aslauga's Knight" as well as "Sintram and his Companions" and "Undine" are referred to in "Jo's Boys", the final book in Alcott's "Little Women" series, where the story of "Aslauga's Knight" mirrors the character Dan and his affection for gentle Bess. "Undine" is the basis, along with Hans Anderson's "Little Mermaid", for Dvořák's opera "Rusalka".

Friedrich Heinrich Karl de la Motte, Baron Fouqué (; 12 February 1777 – 23 January 1843) was a German writer of the Romantic style.


Geographical location.

Tczew is located on the west bank of river Vistula, approximately south of Gdańsk Bay at the Baltic Sea and south-east of Gdańsk.

History.

Middle Ages.

Tczew ("Trsow", "Dersowe", ‘weaver's town’) was first mentioned as "Trsow" in a document by Pomeranian Duke Grzymisław bestowing the land to the Knights Hospitaller in 1198. Around 1200 Sambor I, Duke of Pomerania, built a fortress here. In some documents, the name Derszewo appears, which stems from the name of a feudal lord, Dersław. It is unknown whether Trsow and Derszewo referred to the same or two neighboring settlements. In order to obtain better control of traffic on the Vistula, Pomeranian Duke Sambor II moved his residence form Lubiszewo Tczewskie to here. By 1252 the settlement was known by the names "Tczew" and "Dirschau".  In 1258 a city council was created and in 1260 Tczew was granted town rights. It is the only case in Poland for a city council to be established before granting city rights. Craft and trade developed, there was a port on the Vistula and a mint. Duke Mestwin II in 1289 brought the Dominican Order to the city. It was part of Poland until 1308. Following the Treaty of Soldin in 1309, Tczew was purchased from Brandenburg by Heinrich von Plötzke of the Teutonic Knights, despite the fact that the initial claims to the region by Brandenburg were of dubious legality. The townspeople were expelled by the Teutonic Knights and the town's organization ceased to exist for more than half a century. It was rebuilt from 1364–1384, and was granted Kulm law by Winrich von Kniprode. In 1434 the town was burnt down by the Hussites. In 1440 the town joined the Prussian Confederation, opposing Teutonic Order's rule. In 1457, during the Thirteen Years’ War, Bohemian mercenaries on the Order's service sold Tczew to Poland in lieu of indemnities. The Second Peace of Thorn (1466) confirmed the incorporation of Tczew to Poland. It became part of the Pomeranian Voivodeship in the newly created Polish province of Royal Prussia, soon also part of the Greater Poland Province of the Polish Crown.

Modern era.

During the Protestant Reformation most of town's inhabitants converted to Lutheranism. In 1626 it was occupied by king Gustav II Adolf of Sweden, who built a pontoon bridge across river Vistula and who had his camp at the southern side of the town. After the war Tczew was visited twice by Polish King Władysław IV Vasa, in 1634/1635 and 1636. Although it was rebuilt, it then suffered during the Polish-Swedish Wars. In a nearby battle on 2 September 1657, the Poles were defeated by the combined troops of Brandenburg and Sweden under general Josias II, Count of Waldeck-Wildungen.  The region was annexed from the Polish-Lithuanian Commonwealth by the Kingdom of Prussia during the First Partition of Poland in 1772. Tczew, as Dirschau, became part of the newly founded Province of West Prussia. During the Napoleonic Wars and the Polish national liberation fights the town was captured by Polish troops of General Jan Henryk Dąbrowski in 1807, but became Prussian again in 1815. It became part of the German Empire in 1871.  The town grew rapidly during the 19th century after the opening of the Prussian Eastern Railway line connecting Berlin and Königsberg, with the Vistula bridge near Dirschau being an important part.  Under Prussian and German rule, the Polish minority suffered from forced Germanization; for example Poles were denied Polish schools, and refused to teach their children German. The German official Heinrich Mettenmeyer wrote that German-appointed teachers were treated with highest disdain by Polish children and their parents  After World War I as a consequence of the Treaty of Versailles Tczew became part of the so-called "Polish Corridor" and was incorporated into the re-established Polish state. On January 30, 1920, Polish General Józef Haller arrived in the town with his troops. The town became a center of cultural activities of the German minority in Poland, a German-language school and a theater was founded. The regional member of the Polish Parliament represented the German minority.  During the Interwar period, Tczew was famous for its maritime academy ("Szkoła Morska") which later moved to Gdynia.

World War II.

According to the city's website, Tczew was the location of the start of World War II when German bombers attacked Polish sapper installations to prevent the bridge from being blown up at 04:34 on 1 September 1939 (the shelling of Westerplatte commenced at 04:45). During the German occupation of Poland (1939–45) Tczew, as "Dirschau", was integrated into Reichsgau Danzig-West Prussia of the administrative district of Regierungsbezirk Danzig of Germany's Third Reich. After World War II the town, was one of the most damaged cities of Gdańsk Pomerania. Virtually none of its remaining factories were capable of production. There had been considerable loss of population down to around 18-20 thousand people. Shortly before the end of World War II it was occupied by the Soviet Army. After the end of war the town became part of People's Republic of Poland and renamed Tczew again. German residents were dispossessed and forcefully expelled; Polish residents took the first effort of reconstruction, and revitalization.  Currently, there are several companies in the electrical industry and machine building.

Number of inhabitants by year.

Note that the above table is based on primary sources which may be biased:

Coat of arms.

The coat of arms of Tczew depicts a red griffin in honor of Duke Sambor II, who granted the town municipal rights in 1260.

Transport.

It is an important railway junction with a classification yard.

English Language Camp.

For the last 19 years, the town has been the host location for the annual English Language Camp. The camp, often nicknamed "Camp Tczew" is hosted by the American-Polish Partnership for Tczew and offers students a three-week program where they have the opportunity to interact with Americans and improve their English.

International relations.

Tczew is twinned with:

Tczew (; ) is a town on the Vistula River in Eastern Pomerania, Kociewie, northern Poland with 60,279 inhabitants (June 2009). The city is known for its Old Town and the Vistula Bridge, or Bridge of Tczew, which played a key role in the Invasion of Poland during World War II.


Life.

Löwith was born in Munich to a Christian family of Jewish descent. He was trained in phenomenology under Heidegger, and they developed a close friendship. However this relationship became estranged with Heidegger's affiliation with Nazism, therefore Löwith had to emigrate from Germany in 1934 because of the Fascist regime. He was an important witness in 1936 to Heidegger's continuing allegiance to Nazism.He went to Italy and in 1936 he went to Japan ( as did figures like Brunner) where he lectured at Tohoku University, which had its own tradition of phenomenology. But because of the alliance between the Third Reich and Japan he had to leave Japan in 1941 and went to the United States. From 1941 to 1952, he taught at the Hartford Theological Seminary and The New School for Social Research. In 1952 he returned to Germany to teach as Professor of Philosophy at Heidelberg, where he died.

Thought.

His main influences include Heidegger, Hegel, Nietzsche, and Kierkegaard. His writing after WWII can be read in the same vein as other Christian philosophers and theologians of the 20th century. Often called responses to "crisis", Christian intellectuals of this era, such as Karl Barth (protestant), Florovsky (Orthodox), and Erich Przywara (Roman Catholic), attempted to articulate an understanding of Christian faith in response to the challenges of scientism, secularism, and skepticism.

"Meaning in History".

Löwith's argument in "Meaning in History" is that the western view of history is confused by the relationship between Christian faith and the modern view, which is neither Christian nor pagan. He writes," The modern mind has not made up its mind whether it should be Christian or pagan, it sees with one eye of faith and one of reason. Hence its vision is necessarily dim in comparison with either Greek or biblical thinking." The modern view is progressive, which is to say that it believes that the trajectory of history is moving towards a fulfillment in the bettering of the world by rational and technological means. Löwith believes that the modern view is a sort of Christian "heresy" insofar that is depends on the theology that history has a linear movement, in contrast to Greek pagan cyclical view of history. In this critique Löwith is prophetic in the sense that he anticipates the way post-secular theologians will pick up a similar critique of modernity in the 1990s (such is the case in the Radical Orthodox movement). The modern historical consciousness is, according to Löwith, derived from Christianity. But, this is mistaken because Christians are not a historical people, as their view of the world is based on faith. This explains the tendency in history (and philosophy) to see an eschatological view of human progress. Löwith traces the "regression" of history as opposed to a progression through famous western philosophers and historians. Whereas most genealogies begin from the most antique to the modern, Löwith begins with the most current. He moves from Burckhardt, to Marx, to Hegel, Voltaire, Vico, Bossuet, Augustine, Orosius, and others. He argues that the closer we get to the Biblical vision of history, " I cannot discover the slightest hint of a "philosophy of history". By this he means that a truly theological view of history is not movement to an immanent end, but a transcendent eschatological hope in the consummation of the world. It is not a "philosophy" or attempt to systematize the movement of history. This point is clear in the epilogue of "Meaning in History" where he says, " The attempt at elucidation of the dependence of the philosophy of history on the eschatological history of fulfillment and salvation does not solve the problem of historical thinking." Here he seems to argue that like the progressive view any theological view that tries to equate the happenings of history with God's action is inadequate, which reveals his true argument: We cannot understand the happening of history by reason.  Returning to the idea that Löwith like Barth and others was trying to rethink Christian faith in light of the crisis of world war, Lowith's real concern is the relationship between faith and reason or more specifically faith and history. He writes,"The Christian hope is not a worldly desire and expectation that something will probably happen but a cast of mind based on an unconditional faith in God's redemptive purpose. Genuine hope is, therefore, as free and absolute as the act of faith itself. Both hope and faith are Christian virtues of Grace. The reasons for such an unconditional hope and faith cannot rest on rational calculation of their reasonableness. Hence hope can never be refuted by so-called facts; it can neither be assured no discredited by an established experience." His analysis of the relationship between faith and the observable events of history is one of absolute disconnect, which is an idea he seems to adopt from Kierkegaard's similar argument in "Practice in Christianity". Lowith's answer to the change of modernity is to say that Christianity has nothing at all to do with history or reason, rather it is about being given faith, which becomes hope in the God-man. He writes," The question is therefore not the justification of absolute hope and faith by their relative reasonableness, but whether such an unconditional hope and faith can be put into man instead of God and the God-man. Hope is justified only by faith which justifies itself."  So, whereas the "liberal" Christianity of his contemporaries tried to accommodate or assimilate faith with reason, Lowith maintains that faith justifies itself.

Karl Löwith (9 January 1897 – 26 May 1973) was a German philosopher in the phenomenological tradition. A student of Husserl and Heidegger, he was one of the most prolific German philosophers of the twentieth century.


Life.

Bertram was born in Minden. He is first recorded in Hamburg in 1367, and lived there for the rest of his life, becoming a citizen and Master in 1376, and achieving considerable prosperity. In 1390 he made a will in advance of an intended pilgrimage to Rome, but if he made the journey it had no detectable influence on his art. He was married, but his wife had died by his second will in 1410, when he had a surviving daughter. He died in Hamburg.

Works.

His most famous surviving work is the large "Grabow Altarpiece" (or "Petri-Altar") in the Kunsthalle Hamburg, the largest and most important North German painting of the period. There is a 45-scene altarpiece of the Apocalypse, probably by his workshop, in the Victoria and Albert Museum in London. He, or his workshop, also produced sculpture, presumably in wood; in fact in his first years in Hamburg most surviving documentation relates to sculpture, including chandeliers. A sculpture group depicting Saint Christopher by his hand is located in Falsterbo church, Sweden.  His style is less emotional than that of his Hamburg near-contemporary Master Francke, but has great charm.  Bertram was largely forgotten after the Renaissance until the end of the 19th century when, like Master Francke, he was rediscovered and published by Alfred Lichtwark, director of the Hamburg Kunsthalle.

Asteroid.

Asteroid 85320 Bertram, discovered by German astronomer Freimut Börngen in 1995, was named after Master Bertram. The official was published by the Minor Planet Center on 18 September 2005 ().

Master Bertram (c.1345–c.1415), also known as Meister Bertram and Master of Minden, was a German International Gothic painter primarily of religious art.


Development history.

"Simutrans" was originally written by Hansjörg Malthaner in 1997. Around 2004 he retired from development, and an international community of volunteers took over the development. "Simutrans" was developed internally as a closed source game until 2007, when the software was relicensed under the Artistic License.  Simutrans is ported to Microsoft Windows, Linux, BeOS/Haiku, Mac OS X and AmigaOS 4.x which make use of several graphics libraries such as GDI (Windows only), SDL (all versions) or Allegro (BeOS only). It is portable to any architecture using GCC and one of the aforementioned libraries. "Simutrans" has also multilingual support.  Currently the stable release of "Simutrans" is version 121.0 as of December 1, 2019. There is a popular branch of the code called Simutrans-Extended, which aims to extend the basic game. Simutrans-Extended was formerly called Simutrans-Experimental, but changed its name to Simutrans-Extended on February 13, 2017 to make clear that it is a distinct fork of Simutrans and not a testing branch. Nightly builds for "Simutrans" and the main PakSets are also released for both standard and Extended versions.

Overview and features.

The main goal in "Simutrans" is to provide an efficient transport system for passengers, mail and goods to be transported to their desired destinations fast and with minimal transfers and at the same time making the company grow avoiding bankruptcy or administration.  "Simutrans" has a number of factory chains that are interconnected with other chains, for example, a coal mine produces coal for a coal power plant, and an oil rig produces oil for an oil power plant. The goods produced by these factories may be distributed to smaller factories or shops, such as gasoline to a gas station, coming from a gas storage facility, which retrieves the gas from an oil refinery, and so on.  Supplying a factory with electric power will increase the production and allows for fine-tuning the economy. Passengers and mail are transported between different cities and tourist attractions, and may use several methods of transportation to reach their destinations.  The "Simutrans" executable can run many different paksets, which is a package containing files called paks. Paks are files with graphic and data files that Simutrans uses to determine the objects in the game, their resolution, appearance, and behavior. Gaming experience is therefore very dependent on the pakset used.  "Simutrans" currently features 12 AI players, and has an online capability similar to "OpenTTD" since version 110.0. The terrain in "Simutrans" is freely-modifiable, and different layers like tunnels and bridges can be stacked, allowing for subways or highways to be constructed. It has a day and night cycle, different climates and seasons. Nearly all modes of transportation exist in "Simutrans". At least buses/trucks, trains, and ships are always provided. If defined in the pakset, aircraft, monorails and maglevs can also be used.

Customization.

The "Simutrans" executable must load a pakset which contains the game's objects. Over the years several paksets have been created. An overview is given on the official page.  "Simutrans" can easily be expanded or modified. Simple modification can be done via editing the personal config file. Since the objects in the game just consist of a simple image and a short description file, it is very easy to create a house or add a train. Thus many contributed objects for all graphic sizes exist. The user can also add height maps and citylists which add city names into the game. Even deep modifications of the game mechanics are possible via the config file, like a setting to prevent stockpiling at factories or changing the economic model simulation.

Critical reception.

GameDaily's Big Download considered "Simutrans" to be one of the best freeware games, highlighting the logical system of routing passengers and freight to their destinations, decent AI opponents and the support for custom aesthetics or rules-sets. However, the sometimes unreliable vehicle pathfinding was criticized, particularly with respect to alternate routes and switches for train lines. The sound effects were deemed to be unengaging, and new players may be baffled by the range of transportation possibilities.  Another review from Amiga Future came to very similar conclusions (apart from the lack of sound support on Amiga OS). In particular the depth of simulation and the stability were highlighted.  Between 2007 and June 2017 Simutrans was downloaded from Sourceforge over 5.6 million times.

Simutrans is a cross-platform simulation game in which the player strives to run a successful transport system by constructing and managing transportation systems for passengers, mail and goods by land (rail, road, tram, monorail, maglev), air (airplanes) and water (ship) between places. Like "OpenTTD", "Simutrans" is an open-source transportation game based on the "Transport Tycoon" idea.


Geography.

The Tigris is 1,750 km long, rising in the Taurus Mountains of eastern Turkey about 25 km southeast of the city of Elazig and about 30 km from the headwaters of the Euphrates. The river then flows for 400 km through Turkish Kurdistan before becoming part of the Syria-Turkey border. This stretch of 44 km is the only part of the river that is located in Syria. Some of its affluences are Garzan, Anbarçayi, Batman, and the Great and the Little Zab.  Close to its confluence with the Euphrates, the Tigris splits into several channels. First, the artificial Shatt al-Hayy branches off, to join the Euphrates near Nasiriyah. Second, the Shatt al-Muminah and Majar al-Kabir branch off to feed the Central Marshes. Further downstream, two other distributary channels branch off (the Al-Musharrah and Al-Kahla), to feed the Hawizeh Marshes. The main channel continues southwards and is joined by the Al-Kassarah, which drains the Hawizeh Marshes. Finally, the Tigris joins the Euphrates near al-Qurnah to form the Shatt-al-Arab. According to Pliny and other ancient historians, the Euphrates originally had its outlet into the sea separate from that of the Tigris.  Baghdad, the capital of Iraq, stands on the banks of the Tigris. The port city of Basra straddles the Shatt al-Arab. In ancient times, many of the great cities of Mesopotamia stood on or near the Tigris, drawing water from it to irrigate the civilization of the Sumerians. Notable Tigris-side cities included Nineveh, Ctesiphon, and Seleucia, while the city of Lagash was irrigated by the Tigris via a canal dug around 2900 B.C.

Navigation.

The Tigris has long been an important transport route in a largely desert country. Shallow-draft vessels can go as far as Baghdad, but rafts are needed for transport upstream to Mosul.  General Francis Rawdon Chesney hauled two steamers overland through Syria in 1836 to explore the possibility of an overland and river route to India. One steamer, the "Tigris", was wrecked in a storm which sank and killed twenty. Chesney proved the river navigable to powered craft. Later, the Euphrates and Tigris Steam Navigation Company was established in 1861 by the Lynch Brothers trading company, who had two steamers in service. By 1908 ten steamers were on the river. Tourists boarded steam yachts to venture inland as this was the first age of archaeological tourism, and the sites of Ur and Ctesiphon became popular with European travelers.  In the First World War, during the British conquest of Ottoman Mesopotamia, Indian and Thames River paddlers were used to supply General Charles Townsend's army, in the Siege of Kut and the Fall of Baghdad (1917). The Tigris Flotilla included vessels Clio, Espiegle, Lawrence, Odin, armed tug Comet, armed launches Lewis Pelly, Miner, Shaitan, Sumana, and sternwheelers Muzaffari/Muzaffar. These were joined by Royal Navy Fly-class gunboats Butterfly, Cranefly, Dragonfly, Mayfly, Sawfly, Snakefly, and Mantis, Moth, and Tarantula.  After the war, river trade declined in importance during the 20th century as the Basra-Baghdad-Mosul railway, a previously unfinished portion of the Baghdad Railway, was completed and roads took over much of the freight traffic.

Etymology.

The Ancient Greek form "Tigris" () meaning "tiger" (if treated as Greek) was adapted from Old Persian "Tigrā", itself from Elamite "Tigra", itself from Sumerian "Idigna".  The original Sumerian "Idigna" or "Idigina" was probably from *"id (i)gina" "running water", which can be interpreted as "the swift river", contrasted to its neighbour, the Euphrates, whose leisurely pace caused it to deposit more silt and build up a higher bed than the Tigris. The Sumerian form was borrowed into Akkadian as "Idiqlat", and from there into the other Semitic languages (cf. Hebrew Ḥîddeqel, Syriac "Deqlaṯ", Arabic "Dijlah").  Another name for the Tigris used in Middle Persian was "Arvand Rud", literally "swift river". Today, however, "Arvand Rud" (New Persian: ) refers to the confluence of the Euphrates and Tigris rivers (known in Arabic as the Shatt al-Arab). In Kurdish, it is also known as "Ava Mezin", "the Great Water".  The name of the Tigris in languages that have been important in the region:

Management and water quality.

The Tigris is heavily dammed in Iraq and Turkey to provide water for irrigating the arid and semi-desert regions bordering the river valley. Damming has also been important for averting floods in Iraq, to which the Tigris has historically been notoriously prone following April melting of snow in the Turkish mountains.  Recent Turkish damming of the river has been the subject of some controversy, for both its environmental effects within Turkey and its potential to reduce the flow of water downstream. Mosul Dam is the largest dam in Iraq.  Water from both rivers is used as a means of pressure during conflicts.  In 2014 a major breakthrough in developing consensus between multiple stakeholder representatives of Iraq and Turkey on a Plan of Action for promoting exchange and calibration of data and standards pertaining to Tigris river flows was achieved. The consensus which is referred to as the "Geneva Consensus On Tigris River" was reached at a meeting organized in Geneva by the think tank Strategic Foresight Group.  In February 2016, the United States Embassy in Iraq as well as the Prime Minister of Iraq Haider al-Abadi issued warnings that Mosul Dam could collapse. The United States warned people to evacuate the floodplain of the Tigris because between 500,000 and 1.5 million people were at risk of drowning due to flash flood if the dam collapses, and that the major Iraqi cities of Mosul, Tikrit, Samarra, and Baghdad were at risk.

Religion and mythology.

In Sumerian mythology, the Tigris was created by the god Enki, who filled the river with flowing water.  In Hittite and Hurrian mythology, "Aranzah" (or "Aranzahas" in the Hittite nominative form) is the Hurrian name of the Tigris River, which was divinized. He was the son of Kumarbi and the brother of Teshub and Tašmišu, one of the three gods spat out of Kumarbi's mouth onto Mount Kanzuras. Later he colluded with Anu and the Teshub to destroy Kumarbi (The Kumarbi Cycle).  The Tigris appears twice in the Old Testament. First, in the Book of Genesis, it is the third of the four rivers branching off the river issuing out of the Garden of Eden. The second mention is in the Book of Daniel, wherein Daniel states he received one of his visions "when I was by that great river the Tigris".  The Tigris River is also mentioned in Islam. The tomb of Imam Ahmad Bin Hanbal and Syed Abdul Razzaq Jilani is in Baghdad and the flow of Tigris restricts the number of visitors. The river featured on the coat of arms of Iraq from 1932–1959.

The Tigris () (Turkish: "Dicle)" is the eastern of the two great rivers that define Mesopotamia, the other being the Euphrates. The river flows south from the mountains of southeastern Turkey through Iraq and empties into the Persian Gulf.


Theories on successful manipulation.

According to psychology author George K. Simon, successful psychological manipulation primarily involves the manipulator:  Consequently, the manipulation is likely to be accomplished through covert aggressive means.

According to Braiker.

Harriet B. Braiker (2004) identified the following ways that manipulators control their victims:

According to Simon.

Simon identified the following manipulative techniques:

Vulnerabilities exploited by manipulators.

According to Braiker's self-help book, manipulators exploit the following vulnerabilities (buttons) that may exist in victims:  According to Simon, manipulators exploit the following vulnerabilities that may exist in victims:  Manipulators generally take the time to scope out the characteristics and vulnerabilities of their victims.  Kantor advises in his book "The Psychopathology of Everyday Life: How Antisocial Personality Disorder Affects All of Us" that vulnerability to psychopathic manipulators involves being too:

Motivations of manipulators.

Manipulators can have various possible motivations, including but not limited to:

Psychopathy.

Being manipulative appears in Factor 1 of the Hare Psychopathy Checklist (PCL).

In the workplace.

One approach to management in general identifies a very fine, almost non-existent dividing line between management and manipulation.  The workplace psychopath may often rapidly shift between emotions – used to manipulate people or to cause high anxiety.  The authors of the book "" describe a five-phase model of how a typical workplace psychopath climbs to and maintains power. In phase three (manipulation) the psychopath will create a scenario of "psychopathic fiction" where positive information about themselves and negative disinformation about others will be created, where one's role as a part of a network of pawns or patrons will be utilised and one will be groomed into accepting the psychopath's agenda.

Antisocial, borderline and narcissistic personality disorders.

According to Kernberg, antisocial, borderline, and narcissistic personality disorders are all organized at a borderline level of personality organization, and the three share some common characterological deficits and overlapping personality traits, with deceitfulness and exceptional manipulative abilities being the most common traits among antisocial and narcissism. Borderline is emphasized by unintentional and dysfunctional manipulation, but stigma towards borderlines being deceitful still wrongfully persists. Antisocials, borderlines, and narcissists are often pathological liars. Other shared traits may include pathological narcissism, consistent irresponsibility, Machiavellianism, lack of empathy, cruelty, meanness, impulsivity, proneness to self-harm and addictions, interpersonal exploitation, hostility, anger and rage, vanity, emotional instability, rejection sensitivity, perfectionism, and the use of primitive defence mechanisms that are pathological and narcissistic. Common narcissistic defences include splitting, denial, projection, projective identification, primitive idealization and devaluation, distortion (including exaggeration, minimization and lies), and omnipotence.  Psychologist Marsha M. Linehan has stated that people with borderline personality disorder often exhibit behaviors which are not truly manipulative, but are erroneously interpreted as such. According to her, these behaviors often appear as unthinking manifestations of intense pain, and are often not deliberate as to be considered truly manipulative. In the DSM-V, manipulation was removed as a defining characteristic of borderline personality disorder.  Manipulative behavior is intrinsic to narcissists, who use manipulation to obtain power and narcissistic supply. Those with antisocial personalities will manipulate for material items, power, revenge, and a wide variety of other reasons.

Histrionic personality disorder.

People with histrionic personality disorder are usually high-functioning, both socially and professionally. They usually have good social skills, despite tending to use them to manipulate others into making them the center of attention.

Machiavellianism.

Machiavellianism is a term that some social and personality psychologists use to describe a person's tendency to be unemotional, uninfluenced by conventional morality and more prone to deceive and manipulate others. In the 1960s, Richard Christie and Florence L. Geis developed a test for measuring a person's level of Machiavellianism (sometimes referred to as the "Machiavelli test").

Psychological manipulation is a type of social influence that aims to change the behavior or perception of others through indirect, deceptive, or underhanded tactics. By advancing the interests of the manipulator, often at another's expense, such methods could be considered exploitative and devious.


The Arts and Crafts movement in the West.

The Arts and Crafts movement originated as late 19th-century design reform and social movement principally in Europe, North America and Australia, and continues today. Its proponents are motivated by the ideals of movement founders such as William Morris and John Ruskin, who proposed that in pre-industrial societies, such as the European Middle Ages, people had achieved fulfillment through the creative process of handicrafts. This was held up in contrast to what was perceived to be the alienating effects of industrial labor.  These activities were called "crafts" because originally many of them were professions under the guild system. Adolescents were apprenticed to a master craftsman and refined their skills over a period of years in exchange for low wages. By the time their training was complete, they were well equipped to set up in trade for themselves, earning their living with the skill that could be traded directly within the community, often for goods and services. The Industrial Revolution and the increasing mechanization of production processes gradually reduced or eliminated many of the roles professional craftspeople played, and today many handicrafts are increasingly seen, especially when no longer the mainstay of a formal vocational trade, as a form of hobby, folk art and sometimes even fine art.  The term "handicrafts" can also refer to the products themselves of such artisanal efforts, that require specialized knowledge, maybe highly technical in their execution, require specialized equipment and/or facilities to produce, involve manual labor or a blue-collar work ethic, are accessible to the general public, and are constructed from materials with histories that exceed the boundaries of Western "fine art" tradition, such as ceramics, glass, textiles, metal and wood. These products are produced within a specific community of practice, and while they mostly differ from the products produced within the communities of art and design, the boundaries often overlap, resulting in hybrid objects. Additionally, as the interpretation and validation of art is frequently a matter of context, an audience may perceive handcrafted objects as art objects when these objects are viewed within an art context, such as in a museum or in a position of prominence in one's home.

In modern education.

Simple "arts and crafts" projects are a common elementary and middle school activity in both mainstream and alternative education systems around the world.  In some of the Scandinavian countries, more advanced handicrafts form part of the formal, compulsory school curriculum, and are collectively referred to as "slöjd" in Swedish, and "käsityö" or "veto" in Finnish. Students learn how to work mainly with metal, textile and wood, not for professional training purposes as in American vocational–technical schools, but with the aim to develop children's and teens' practical skills, such as everyday problem-solving ability, tool use, and understanding of the materials that surround us for economical, cultural and environmental purposes.  Secondary schools and college and university art departments increasingly provide elective options for more handicraft-based arts, in addition to formal "fine arts", a distinction that continues to fade throughout the years, especially with the rise of studio craft, i.e. the use of traditional handicrafts techniques by professional fine artists.  Many community centers and schools run evening or day classes and workshops, for adults and children, offering to teach basic craft skills in a short period of time.

List of common handicrafts.

There are almost as many variations on the theme of handicrafts as there are crafters with time on their hands, but they can be broken down into a number of categories:

Sales venues.

Handicrafts are often made for home use. If sold, they are sold in direct sales, gift shops, public markets, and online shopping. In developing countries, handicrafts are sold to locals and as souvenirs to tourists. Sellers tend to speak at least a few words of common tourist languages. There are also specialty markets such as:

A handicraft, sometimes more precisely expressed as artisanal handicraft or handmade, is any of a wide variety of types of work where useful and decorative objects are made completely by hand or by using only simple tools. It is a traditional main sector of craft and applies to a wide range of creative and design activities that are related to making things with one's hands and skill, including work with textiles, moldable and rigid materials, paper, plant fibers, etc. One of the world's oldest handicraft is Dhokra; this is a sort of metal casting that has been used in India for over 4,000 years and is still used. In Iranian Baluchistan, women still make red ware hand made pottery with dotted ornaments much similar to the 5000 year old pottery tradition of Kalpurgan, an archaeological site near the village. Usually, the term is applied to traditional techniques of creating items (whether for personal use or as products) that are both practical and aesthetic. Handicraft industries are those that produce things with hands to meet the needs of the people in their locality. Machines are not used.


Early life.

Schütz was born in Köstritz, the eldest son of Christoph Schütz and Euphrosyne Bieger.  In 1590 the family moved to Weißenfels, where his father managed the inn "Zum güldenen Ring". His father eventually served as burgomaster in Weißenfels, and in 1615 purchased another inn known as both "Zur güldenen Sackpfeife" and "Zum güldenen Esel" – which he renamed "Zum Schützen".  While Schütz was living with his parents, his musical talents were discovered by Landgrave Moritz von Hessen-Kassel in 1598 during an overnight stay in Christoph Schütz's inn. Upon hearing young Heinrich sing, the landgrave requested that his parents allow the boy to be sent to his noble court for further education and instruction. His parents initially resisted the offer, but after much correspondence they eventually took Heinrich to the landgrave's seat at Kassel in August 1599.  After being a choir-boy he went on to study law at Marburg before going to Venice from 1609–1612 to study music with Giovanni Gabrieli. Gabrieli is the only person Schütz ever referred to as being his teacher. He also inherited a ring from Gabrieli shortly before the latter's death. He subsequently was organist at Kassel from 1613 to 1615.

Dresden (1615–1672).

After a prolonged yet polite negotiation between the Landgrave and the Elector, Schütz moved to Dresden in 1615 to work as court composer to the Elector of Saxony. In 1619 Schütz married Magdalena Wildeck (born 1601). She bore two daughters before her death in 1625: Anna Justina, born in 1621, and Euphrosyne, born in 1623.  In Dresden Schütz sowed the seeds of what is now the Sächsische Staatskapelle Dresden, but left there on several occasions; in 1628 he went to Venice again, where he met and studied with Claudio Monteverdi. In 1633 he was invited to Copenhagen to compose the music for wedding festivities there, eventually returning to Dresden in 1635. He again conducted an extended visit to Denmark in 1641, due to the devastation of the Electoral court. The Thirty Years' War ended in 1648, and he again became more active in Dresden. In 1655, the year that his daughter Euphrosyne died, he accepted an "ex officio" post as Kapellmeister at Wolfenbüttel.  His Dresden compositions during the Thirty Years' War were, by necessity of the times, smaller scale than the oft-massive works before, although this period produced much of his most charming music. After the war, Schütz again wrote larger-scale compositions culminating in the 1660s, when he composed the greatest Passionmusic before Bach. Schütz moved back to Weißenfels, in a retirement he had to beg for, to live with his sister (the house is now a fine museum of his life), but the Electoral Court often called him back to Dresden. He died in Dresden from a stroke in 1672 at the age of 87. He was buried in the old Dresden Frauenkirche, but his tomb was destroyed in 1727 when the church was torn down to build the new Dresden Frauenkirche. (His long-time house on the same square has been reconstructed in the same style and is an apartment building with hotel rooms and a restaurant.)  His pupils included Anton Colander, Christoph Bernhard, Matthias Weckmann, Heinrich Albert, Johann Theile, Friedrich Werner, Philipp Stolle Johann Nauwach, Caspar Kittel, Christoph Kittel, Clemens Thieme, Johann Klemm, Johann Vierdanck, David Pohle, Constantin Christian Dedekind, Johann Jakob Loewe (or Löwe), Johann Kaspar Horn, Friedrich von Westhoff, Adam Krieger, Johann Wilhelm Furchheim, Carlo Farina. ()

Style.

Schütz's compositions show the influence of his teacher Gabrieli (displayed most notably with Schütz's use of resplendent polychoral and concertato styles) and of Monteverdi. Additionally, the influence of the Netherlandish composers of the 16th century is prominent in his work. His best known works are in the field of sacred music, ranging from solo voice with instrumental accompaniment to a cappella choral music. Representative works include his Psalmen Davids" (Psalms of David, Opus 2), Cantiones sacrae" (Opus 4), three books of "Symphoniae sacrae", "Die sieben Worte Jesu Christi am Kreuz" (The seven words of Jesus Christ on the Cross), three Passion settings and the Christmas Story. Schütz's music, while starting off in the most progressive styles early in his career, eventually grew into a style that is simple and almost austere, culminating with his late Passion settings. Practical considerations were certainly responsible for part of this change: the Thirty Years' War had devastated the musical infrastructure of Germany, and it was no longer practical or even possible to put on the gigantic works in the Venetian style which marked his earlier period.  The unique composition "Es steh Gott auf" (SWV 356) is in many respects comparable to Monteverdi. His funeral music "Musikalische Exequien" (1636) for his noble friend Heinrich Posthumus of Reuss is considerad a masterpiece, and is known today as the first German Requiem. Schütz was equally fluent in his Latin or Germanic styles.  Schütz was one of the last composers to write in a modal style. His harmonies often result from the contrapuntal alignment of voices rather than from any sense of "harmonic motion"; contrastingly, much of his music shows a strong tonal pull when approaching cadences. His music includes a great deal of imitation, but structured in such a way that the successive voices do not necessarily enter after the same number of beats or at predictable intervallic distances. This contrasts sharply with the manner of his contemporary Samuel Scheidt, whose counterpoint usually flows in regularly spaced entries. Schütz's writing often includes intense dissonances caused by the contrapuntal motion of voices moving in correct individual linear motion, but resulting in startling harmonic tension. Above all, his music displays extreme sensitivity to the accents and meaning of the text, which is often conveyed using special technical figures drawn from "musica poetica," themselves drawn from or created in analogy to the verbal figures of classical rhetoric. However, as noted above, the composer's style became simpler in his later works, which make less frequent use of the kind of distantly related chords and licences found in such pieces as "Was hast du verwirket" (SWV 307) from "Kleine geistliche Konzerte II".  Beyond the early book of madrigals, almost no secular music by Schütz has survived, save for a few domestic songs ("arien") and occasional commemorative items (such as "Wie wenn der Adler sich aus seiner Klippe schwingt" (SWV 434), and no purely instrumental music at all (unless one counts the short instrumental movement entitled "sinfonia" that encloses the dialogue of "Die sieben Worte"), even though he had a reputation as one of the finest organists in Germany.  Schütz was of great importance in bringing new musical ideas to Germany from Italy, and thus had a large influence on the German music which was to follow. The style of the North German organ school derives largely from Schütz (as well as from the Dutchman Jan Pieterszoon Sweelinck); a century later this music was to culminate in the work of J.S. Bach. After Bach, the most important composers to be influenced by Schütz were Anton Webern and Brahms, who were known to have studied his works.

Works.

The following are major published works; most of these contain multiple pieces of music; single published works are also listed in the complete work list, including major works such as the "Seven Last Words", and the Passions (according to Matthew, Luke, and John). There are over 500 total surviving individual pieces by Schütz.

Heinrich Schütz (; 6 November 1672) was a German composer and organist, generally regarded as the most important German composer before Johann Sebastian Bach, as well as one of the most important composers of the 17th century. He is credited with bringing the Italian style to Germany and continuing its evolution from the Renaissance into the Early Baroque. Most of his surviving music was written for the Lutheran church, primarily for the Electoral Chapel in Dresden. He wrote what is traditionally considered to be the first German opera, "Dafne", performed at Torgau in 1627, the music of which has since been lost, along with nearly all of his ceremonial and theatrical scores.


Roles in human civilization.

Historically, letters have existed from the time of ancient India, ancient Egypt and Sumer, through Rome, Greece and China, up to the present day. During the seventeenth and eighteenth century, letters were used to self-educate. Letters were a way to practice critical reading, self-expressive writing, polemical writing and also exchange ideas with like-minded others. For some people, letters were seen as a written performance. For others, it was not only seen as a performance but also as a way of communication and a method of gaining feedback. Letters make up several of the books of the Bible. Archives of correspondence, whether for personal, diplomatic, or business reasons, serve as primary sources for historians. At certain times, the writing of letters was thought to be an art form and a genre of literature, for instance in Byzantine epistolography.  In the ancient world letters were written on a various different materials, including metal, lead, wax-coated wooden tablets, pottery fragments, animal skin, and papyrus. From Ovid, we learn that Acontius used an apple for his letter to Cydippe.  As communication technology has diversified, posted letters have become less important as a routine form of communication. For example, the development of the telegraph drastically shortened the time taken to send a communication, by sending it between distant points as an electrical signal. At the telegraph office closest to the destination, the signal was converted back into writing on paper and delivered to the recipient. The next step was the telex which avoided the need for local delivery. Then followed the fax (facsimile) machine: a letter could be transferred from the sender to the receiver through the telephone network as an image. These technologies did not displace physical letters as the primary route for communication, however today, the internet, by means of email, plays the main role in written communications; however, these email communications are not generally referred to as letters but rather as e-mail (or email) messages, messages or simply emails or e-mails, with only the term "letter" generally being reserved for communications on paper.

As literary historical source material.

Due to the timelessness and universality of letter writing, there is a wealth of letters and instructional materials (for example, manuals, as in the medieval ars dictaminis) on letter writing throughout history. The study of letter writing usually involves both the study of rhetoric and grammar.

Comparison with electronic mail.

Despite email, letters are still popular, particularly in business and for official communications. At the same time, many "letters" are sent in electronic form. Nevertheless, frequently, the following arguments are put forth saying letters may have the advantages over email:

Delivery process.

Here is how a letter gets from the sender to the recipient:  This process, depending on how far the sender is from the recipient, can take anywhere from a day to 3–4 weeks. International mail is sent via trains and airplanes to other countries.  However, in 2008, Janet Barrett from the UK, received a RSVP to a party invitation addressed to 'Percy Bateman', from 'Buffy', originally posted on 29 November 1919. It had taken 89 years to be delivered by the Royal Mail. However, Royal Mail denied this, saying that it would be impossible for a letter to have remained in their system for so long, as checks are carried out regularly. Instead, the letter dated 1919 may have "been a collector's item which was being sent in another envelope and somehow came free of the outer packaging".

Kinds of letters.

There are a number of different types of letter:

A letter is a written message conveyed from one person to another person through a medium. Letters can be formal and informal. Besides a means of communication and a store of information, letter writing has played a role in the reproduction of writing as an art throughout history. Letters have been sent since antiquity and are mentioned in the "Iliad". Historians Herodotus and Thucydides mention and utilize letters in their writings.


History.

Until 1774, the region belonged to the Crimean Khanate.  Kherson was founded in 1778 by Grigori Aleksandrovich Potemkin, on the orders of Catherine the Great. The city was built under the supervision of General Ivan Gannibal on the site of a small fortress called Aleksanderschanz. The name Kherson is a contraction of Chersonesos, an ancient Greek colony founded approximately 2500 years ago in the southwestern part of Crimea. One of the first buildings in the Kherson Fort was the Church of St. Catherine, where Potemkin was eventually buried. The last tarpan was caught near Kherson in 1866.  During the Ukrainian revolution of 2014, the city was a scene of riots against President Yanukovich, during which the main Lenin statue of the city was toppled by protesters. After the revolution the city became relatively calm.

Demographics.

Ethnicity.

As of Ukrainian National Census (2001), the ethnic groups living within Kherson were:  The ethnic groups living within Kherson as of the 1926 Census:

Administrative divisions.

There are three city raions.

Climate.

Under the Köppen climate classification, Kherson has a humid continental climate ("Dfa").

Transport.

Rail.

Kherson is connected to the national railroad network of Ukraine. There are daily long-distance services to Kiev, Lviv and other cities.

Air.

Kherson is served by Kherson International Airport providing both passport and customs control. It operates a 2,500 x 42-meter concrete runway, accommodating Boeing 737, Airbus 319/320 aircraft, and helicopters of all series.  The official airport website is http://www.airport.kherson.ua and additional info can be found at http://www.aisukraine.net.

Education.

There are 77 high schools as well as 5 colleges. There are 15 institutions of higher education.

Kherson (, ;, ) is a city in southern Ukraine. It functions as the administrative center of Kherson Oblast (province). Designated as a city of oblast significance. Kherson is an important port on the Black Sea and on the Dnieper River, and the home of a major ship-building industry. it had a population of.


Geography.

This small town is located in the west of the Upper Lusatia historic region (West Lusatia), about northeast of Dresden and about northwest of Bautzen. Situated on the Black Elster river, between the West Lusatian Hills and the Lusatian Highlands rising in the south, the town was built on greywacke and granite rocks which were mined here for centuries. Kamenz railway station is the terminus of Lübbenau–Kamenz and Kamenz–Pirna railway lines. It is served by "Regionalbahn" trains from Dresden Hauptbahnhof, operated by the Städtebahn Sachsen.  The Hutberg hill west of the town centre, at an elevation of, is the site of an extended landscape park laid out in 1893. It is known for its major rhododendron and azalea collections flowering at Pentecost. In 1864 the Lessing Tower was erected on the hilltop, offering a panoramic view over the West Lusatian lands and the Upper Lusatian Heath and Pond Landscape in the north. About 32% of the nature in former Kamenz District is under protection, including a network of routes for riding by bicycle and hiking.  The Kamenz municipal area comprises the villages of Bernbruch, Biehla, Brauna, Cunnersdorf, Deutschbaselitz/Němske Pazlicy, Gelenau, Hausdorf, Hennersdorf, Jesau/Jěžow, Liebenau, Lückersdorf, Petershain, Rohrbach, Schiedel, Schönbach, Schwosdorf, Thonberg/Hlinowc, Wiesa/Brěznja, and Zschornau/Čornow.

History.

The settlement arose in the late 12th century, when a fortress was erected at the location of today's old town, in order to secure the junction of the medieval Via Regia trade route with the Black Elster river. From here, the Via Regia offered important transport links from the Low Countries up to Silesia.  In 1225 written records first mentioned the town; Kamenz became an independent city in 1319, when Emperor Louis IV enfeoffed the West Lusatian lands to the Luxembourg king John of Bohemia. In 1346, the citizens joined the Lusatian League for protection against robber barons and to maintain public peace ("Landfrieden"). The town was nevertheless besieged and finally occupied by Hussite forces in 1429, who also devastated the nearby town of Wittichenau before they marched against Bautzen. In 1493 King Vladislaus II of Bohemia had a Franciscan monastery established north of the Kamenz town walls, dedicated to Saint Anne in 1512.  Kamenz citizens officially turned Protestant in 1536. In the Schmalkaldic War of 1546/47, the Upper Lusatian towns refused to support the troops of the Habsburg emperor Ferdinand I against the Protestant princes and were penalised with the loss of numerous privileges. The Franciscan convent finally dissolved in 1564.  According to the 1635 Peace of Prague, the Lusatias passed from the Bohemian Crown to the Electorate of Saxony. Several witch-hunts are documented in the 17th century. In 1707 a fire destroyed large parts of the old town. A second major fire on 4 and 5 August 1842 destroyed much of the city.  In 1896 Kamenz became garrison town of the "Königlich Sächsisches Reserve-Infanterie-Regiment Nr. 242", part of the German 53rd Reserve Division. In World War II a subcamp of Gross-Rosen concentration camp was located in the town from 1944 to 1945, where forced labourers worked for a Daimler-Benz aircraft engine factory. The airfield northeast of the town was used by Luftwaffe "Schlachtgeschwader 2" and "Sturzkampfgeschwader 77" units.  After the war, the town became part of the Soviet occupation zone and East Germany. Until 1990, an officer candidate school of the East German Air Force Staff ("Offiziershochschule Franz Mehring") was located at the Kamenz Airfield. The former municipality Schönteichen was merged into Kamenz in January 2019.

Politics.

Seats in the city council ("Stadtrat") as of 2014 local elections:

Twin towns — sister cities.

Kamenz is twinned with:

Kamenz () is a town ("Große Kreisstadt") in the district of Bautzen in Saxony, Germany. Until 2008 it was the administrative seat of Kamenz District. The town is known as the birthplace of the philosopher and poet Gotthold Ephraim Lessing also Bruno Richard Hauptmann. It lies north-east of the major city of Dresden.


Name.

A number of explanations for the origin of the Apache name have been offered over the years.  From the inception of the Apache project in 1995 the official documentation stated:  In an April 2000 interview, Brian Behlendorf, one of the creators of Apache said:  Since 2013 the Apache Foundation has explained the origin of the name as:  When Apache is running under Unix, its process name is, which is short for "HTTP daemon".

Feature overview.

Apache supports a variety of features, many implemented as compiled modules which extend the core functionality. These can range from authentication schemes to supporting server-side programming languages such as Perl, Python, Tcl and PHP. Popular authentication modules include mod_access, mod_auth, mod_digest, and mod_auth_digest, the successor to mod_digest. A sample of other features include Secure Sockets Layer and Transport Layer Security support (mod_ssl), a proxy module (mod_proxy), a URL rewriting module (mod_rewrite), custom log files (mod_log_config), and filtering support (mod_include and mod_ext_filter).  Popular compression methods on Apache include the external extension module, mod_gzip, implemented to help with reduction of the size (weight) of web pages served over HTTP. ModSecurity is an open source intrusion detection and prevention engine for Web applications. Apache logs can be analyzed through a Web browser using free scripts, such as AWStats/W3Perl or Visitors.  Virtual hosting allows one Apache installation to serve many different websites. For example, one computer with one Apache installation could simultaneously serve codice_1, codice_2, codice_3, etc.  Apache features configurable error messages, DBMS-based authentication databases, content negotiation and supports several graphical user interfaces (GUIs).  It supports password authentication and digital certificate authentication. Because the source code is freely available, anyone can adapt the server for specific needs, and there is a large public library of Apache add-ons.  A more detailed list of features is provided below:

Performance.

Instead of implementing a single architecture, Apache provides a variety of MultiProcessing Modules (MPMs), which allow it to run in either a process-based mode, a hybrid (process and thread) mode, or an event-hybrid mode, in order to better match the demands of each particular infrastructure. Choice of MPM and configuration is therefore important. Where compromises in performance must be made, Apache is designed to reduce latency and increase throughput relative to simply handling more requests, thus ensuring consistent and reliable processing of requests within reasonable time-frames.  For delivering static pages, Apache 2.2 series was considered significantly slower than nginx and varnish. To address this issue, the Apache developers created the Event MPM, which mixes the use of several processes and several threads per process in an asynchronous event-based loop. This architecture as implemented in the Apache 2.4 series performs at least as well as event-based web servers, according to Jim Jagielski and other independent sources. However, some independent but significantly outdated benchmarks show that it is still half as fast as nginx, e.g.

Licensing.

The Apache HTTP Server codebase was relicensed to the Apache 2.0 License (from the previous 1.1 license) in January 2004, and Apache HTTP Server 1.3.31 and 2.0.49 were the first releases using the new license.  The OpenBSD project did not like the change and continued the use of pre-2.0 Apache versions, effectively forking Apache 1.3.x for its purposes. They initially replaced it with Nginx, and soon after made their own replacement, OpenBSD Httpd, based on the relayd project.

Versions.

Version 1.1: The Apache License 1.1 was approved by the ASF in 2000: The primary change from the 1.0 license is in the 'advertising clause' (section 3 of the 1.0 license); derived products are no longer required to include attribution in their advertising materials, only in their documentation.  Version 2.0: The ASF adopted the Apache License 2.0 in January 2004. The stated goals of the license included making the license easier for non-ASF projects to use, improving compatibility with GPL-based software, allowing the license to be included by reference instead of listed in every file, clarifying the license on contributions, and requiring a patent license on contributions that necessarily infringe a contributor's own patents.

Development.

The Apache HTTP Server Project is a collaborative software development effort aimed at creating a robust, commercial-grade, feature-rich and freely available source code implementation of an HTTP (Web) server. The project is jointly managed by a group of volunteers located around the world, using the Internet and the Web to communicate, plan, and develop the server and its related documentation. This project is part of the Apache Software Foundation. In addition, hundreds of users have contributed ideas, code, and documentation to the project.  Apache 2.4 dropped support for BeOS, TPF and even older platforms.

Apache HTTP Server, colloquially called Apache ( ), is a free and open-source cross-platform web server software, released under the terms of Apache License 2.0. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation.


Etymology.

The word "philately" is the English transliteration of the French "philatélie", coined by Georges Herpin in 1864. Herpin stated that stamps had been collected and studied for the previous six or seven years and a better name was required for the new hobby than "timbromanie" (roughly "stamp quest"), which was disliked. The alternative terms "timbromania", "timbrophily" and "timbrology" gradually fell out of use as "philately" gained acceptance during the 1860s. He took the Greek root word φιλ(ο)- "phil(o)-", meaning "an attraction or affinity for something", and ἀτέλεια "ateleia", meaning "exempt from duties and taxes" to form "philatelie".

History.

Nineteenth century.

As a collection field, philately appeared after the introduction of the postage stamps in 1840, but did not gain large attraction until the mid-1850s. Some authors believe that the first philatelist appeared on the day of the release of the world's first postage stamp, dated to May 6, 1840, when the Liverson, Denby and Lavie London law office sent a letter to Scotland franked with ten uncut Penny Blacks, stamped with the postmark “LS.6MY6. 1840." In 1992 at an auction in Zurich, this envelope was sold for 690 thousand francs.  Already in 1846, cases of collecting stamps in large numbers were known in England. However, without reason for collection, stamps at this time were used for pasting wallpaper. The first philatelist is considered to be a postmaster going by Mansen, who lived in Paris, and in 1855 had sold his collection, which contained almost all the postage stamps issued by that time. The stamp merchant and second-hand book dealer Edard de Laplante bought it, recognizing the definitive collector's worth of the postage stamp. Due to the boom in popularity and news of this transaction, stamp merchants like Laplante began to emerge.  Towards the end of the 19th century stamp collecting reached hundreds of thousands of people of all classes. Even some states had collections of postage stamps, for example, England, Germany, France, Bavaria, and Bulgaria). In countries who held national collections, museums were built to dedicate that nation's history with philately, and the first such appeared in Germany, France, and Bulgaria. Allegedly, the first of these museums housed the collection of the British Museum, curated by MP Tapling and bequeathed to the Museum in 1891. The Museum für Kommunikation Berlin also had an extensive collection of stamps. The largest collection of the time belonged to Baron Philipp von Ferrary in Paris.  As the number of postage stamp issues increased every year, collection became progressively difficult. Therefore, from the early 1880s, "collector experts" appeared, specializing their collection to only one part of the world, a group of nations, or even only one.

Twentieth century.

Philately as one of the most popular types of collecting continued to develop in the 20th century. Along with the "Scott", "Stanley Gibbons", and "Yvert et Tellier" catalogs, the "Zumstein" (first published in Switzerland, 1909), and the "Michel" (first published in Germany, 1910) catalogs began publication.  In 1934, the idea to celebrate an annual Postage Stamp Day was suggested by Hans von Rudolphi, a German philatelist. The idea was adopted rapidly in Germany, and gained later adoption in other countries. Stamp Day is a memorial day established by the postal administration of a country and annually celebrated, which is designed to attract public attention to, popularize the use of, and expand the reach of postal correspondence, and contribute to the development of philately. In 1968, Cuba dedicated a postage stamp for Stamp Day with an image of G. Sciltian's "El filatelista".  In 1926, the Fédération Internationale de Philatélie (FIP) was founded, where international philatelic exhibitions have been regularly organized since 1929.The first World Philatelic Exhibition in Prague was held between August and September 1962; in 1976, the FIP brought together national societies from 57 countries, which held over 100 exhibitions, and in 1987, over 60 countries entered the FIP.  Since the middle of the 20th century, philately has become the most widespread field of amateur collecting, which was facilitated by:  Philately magazines, at this time, were published as far east as Poland, and as far west as North America. In Canada, "Canadian Stamp News" was established in 1976 as an off-shoot to "Canadian Coin News", which was launched about a decade earlier.  Philately was largely advanced by the USSR and nations within its sphere of influence, and the United States, France, the UK, and Austria. The British Library Philatelic Collections and the postal museums in Stockholm, Paris, and Bern had unique national philately collections at that time, and among the famous private collections are those of the Royal Philatelic Collection, F. Ferrari (Austria), M. Burrus (Switzerland), A. Lichtenstein, A. Hind, J. Boker (USA), and H. Kanai (Japan).  In the mid-1970s, national philately organizations and associations existed in most countries, and 150-200 million people were involved in philately during meetings established.

Twenty-first century.

From August 28 to September 1, 2004, the World Stamp Championship was held for the first time in the history of world philately in Singapore.

Types.

Traditional philately is the study of the technical aspects of stamp production and stamp identification, including:

Tools.

Philately uses several tools, including stamp tongs (a specialized form of tweezers) to safely handle the stamps, a strong magnifying glass and a perforation gauge (odontometer) to measure the perforation gauge of the stamp.  The identification of watermarks is equally important and may be done with the naked eye by turning the stamp over or holding it up to the light. If this fails then "watermark fluid" may be used, which "wets" the stamp to reveal the mark.  Other common tools include stamp catalogs, stamp stock books and stamp hinges.

Organizations.

Philatelic organizations sprang up soon after people started collecting and studying stamps. They include local, national and international clubs and societies where collectors come together to share the various aspects of their hobby.  The world's oldest philatelic society is the Royal Philatelic Society London, which was founded on April 10, 1869, as the Philatelic Society. In North America, the major national societies include the American Philatelic Society; the Royal Philatelic Society of Canada; and the Mexico-Elmhurst Philatelic Society, International.

Philately (; ) is the study of postage stamps and postal history. It also refers to the collection, appreciation and research activities on stamps and other philatelic products. Philately involves more than just stamp collecting or the study of postage; it is possible to be a philatelist without owning any stamps. For instance, the stamps being studied may be very rare or reside only in museums.


History.

In 1845 Don John Bosco ("Don" being a traditional Italian honorific for priest) opened a night school for boys in Valdocco, now part of the municipality of Turin in Italy. In the following years, he opened several more schools, and in 1857 drew up a set of rules for his helpers. This rule was approved definitively in 1873 by Pope Pius IX as the Rule of the Society of Saint Francis de Sales. The Society grew rapidly, with houses established in France and Argentina within a year of the Society's formal recognition. Its official print organ, "Salesian Bulletin," was first published in 1877.  Over the next decade the Salesians expanded into Austria, Britain, Spain, and several countries in South America. The death of Don Bosco in 1888 did not slow the Society's growth. By 1911 the Salesians were established throughout the world, including Colombia, China, India, South Africa, Tunisia, Venezuela and the United States.  The Society continues to operate worldwide; in 2000, it counted more than 17,000 members in 2,711 houses.

Symbols.

Coat of arms.

The Salesian coat of arms was designed by Professor Boidi. It was published for the first time in a circular letter of Don Bosco on 8 December 1885. It consist of a shining star, the large anchor, and the heart on fire to symbolize the theological virtues of Faith, Hope and Charity. The figure of Saint Francis de Sales recalls the patron of the society. The small wood in the lower part refers to the founder of the society; the high mountains signify the heights of perfection towards which members strive; the interwoven palm and laurel that enfold the shield on either side are emblematic of the prize reserved for a virtuous and sacrificial life. The motto "Da mihi animas, caetera tolle" ("Give me souls, take away the rest") is featured at the bottom.

Logo.

The Salesian logo is made up of two superimposed images.  In the background is a globe to represent the worldwide reach of the Salesians, and a stylised "S" in white is formed within the globe, resembling a snaking road representing an educational journey for the youth.  In the foreground is an arrow pointing upwards, resting on three perpendicular legs on top of which are three closed circles, making a stylised image of three people: the first of these in the middle and taller than the others is the point of the arrow, and the other two beside it appear as it were to be embraced by the central figure. These three stylized figures represent Saint John Bosco reaching out to the young, and his call for Salesians to continue his work. The three stylised figures with the arrow pointing upwards can also be viewed as a house dwelling with a sloping roof and three pillars holding it up, represents John Bosco's Oratories of Reason, Religion and Kindness.  The logo combines elements from those of the German and Brazilian provinces. The idea of combining the two came out of suggestions from an enquiry about the new logo conducted throughout the Congregation and from contributions by the General Council. It is designed with the central theme "Don Bosco and the Salesians walking with the young through the world." The artistic work of combining the two was carried out by the designer Fabrizio Emigli, from the Litos Company, in Rome.

Organization.

The Salesians of Don Bosco are headed by the Rector Major and the society's general council, while each of the ninety-four geographical provinces is headed by a Provincial. These officers serve six-year terms; the Rector Major and the members of the general council are elected by the Chapter General, which meets every six years or upon the death of the Rector Major. Each local Salesian community is headed by a superior, called a Rector (or more commonly, "Director"), who is appointed to a three-year term and can be renewed for a second three-year term.  Since 2014, the Rector Major of the Salesians is the Very Reverend Father Ángel Fernández Artime.

Works.

Salesian communities primarily operate shelters for homeless or at-risk youths; schools; technical, vocational, and language instruction centers for youths and adults; and boys' clubs and community centers. In some areas they run parish churches. Salesians are also active in publishing and other public communication activities, as well as mission work, especially in Asia (Siberia - in the Yakutsk area), Africa, and South America (Yanomami). The "Salesian Bulletin" is now published in fifty-two editions, in thirty languages.  In the 1990s Salesians launched new works in the area of tertiary education, and today have a network of over 58 colleges and universities. The official university of the Salesian Society is the Salesian Pontifical University in Rome.

Sexual abuse scandal.

A number of schools and churches established under the Salesians have been at the center of child sex abuse scandals, including Mary Help of Christians in Tampa, Florida. Due to ongoing sexual assault lawsuits and settlements, several boarding schools were closed.

The Salesians of Don Bosco (SDB), officially known as the Society of Saint Francis de Sales (), is a religious congregation of the Catholic Church, founded in the late 19th century by Italian priest Saint John Bosco to help poor children during the Industrial Revolution and named after Saint Francis de Sales, a 17th-century bishop of Geneva.


Design and development.

The basic principle resembles that of the BLU-82 "Daisy Cutter", which was used to clear heavily wooded areas in the Vietnam War. Decades later, the BLU-82 was used in Afghanistan in November 2001 against the Taliban. Its success as a weapon of intimidation led to the decision to develop the MOAB. Pentagon officials suggested MOAB might be used as an anti-personnel weapon, as part of the "shock and awe" strategy integral to the 2003 invasion of Iraq.  GBU-43s are delivered from C-130 cargo aircraft, inside which they are carried on cradles resting on airdrop platforms. The bombs are dropped by deploying drogue parachutes, which also extract the cradle and platform from the aircraft. Shortly after launch the drogues are released and the bomb falls without the use of a retarding parachute. GPS satellite-guidance is used to guide bombs to their targets.  The MOAB is not a penetrator weapon and is primarily an air burst ordnance intended for soft to medium surface targets covering extended areas and targets in a contained environment such as a deep canyon or within a cave system. High altitude carpet-bombing with much smaller bombs delivered via heavy bombers such as the B-52, B-2, or the B-1 is also highly effective at covering large areas.  The MOAB is designed to be used against a specific target, and cannot by itself replicate the effects of a typical heavy bomber mission. During the Vietnam War's Operation Arc Light program, for example, the United States Air Force sent B-52s on well over 10,000 bombing raids, each usually carried out by two groups of three aircraft. A typical mission dropped 168 tons of ordnance, pounding an area 1.5 by 0.5 miles with an explosive force equivalent to 10 to 17 MOABs.  MOAB was first tested with the explosive tritonal on 11 March 2003, on Range 70 located at Eglin Air Force Base in Florida. It was tested again on 21 November 2003.  Since 2003, 15 MOABs have been manufactured at the McAlester Army Ammunition Plant in McAlester, Oklahoma.  The Air Force has said the MOAB has a unit price of $170,000, but this is a historical unit cost made in the mid-2000s and various factors of the bomb's atypical development process have made exact cost estimation difficult. The Air Force Research Lab generated the value based on already existing parts such as bomb casing and metals, and since the bomb was built in-house by the service they did not pay for outside research or have standard procurement costs associated with it. MOAB was a "crash project" developed for use against an adversary with uncertain tactics on unfamiliar terrain, and so was an effort to meet an urgent need rather than a formal program. Should more bombs be ordered to be built, manufacturing would likely be started over with higher costs due to a lack of old parts, price inflation, and new design and testing.

Operational use.

On 13 April 2017, a MOAB was dropped on an ISIS-Khorasan cave complex in Achin District, Nangarhar Province, Afghanistan. It was the first operational use of the bomb. Two days later, an Afghan army spokesman said that the strike killed 94 ISIS-K militants, including four commanders, with no signs of civilian casualties. However, an afghani parliamentarian from Nangarhar province, Esmatullah Shinwari, said locals told him the explosion killed a teacher and his young son. Former US military official Marc Garlasco, who served in the George W. Bush administration, said that the US had not previously used the MOAB because of worries that it would inadvertently hurt or kill civilians. The MOAB's explosive power and symbolism made it a persuasive example of weaponized war propaganda.

Similar weapons.

During World War II, Royal Air Force Bomber Command used the Grand Slam, officially known as the "Bomb, Medium Capacity, 22,000 lb" 42 times. At total weight, these earthquake bombs were technically larger than the MOAB. However, half their weight was due to the cast iron casing necessary for penetrating the ground (up to 40 m) before exploding. The MOAB, in contrast, has a light aluminum casing surrounding of explosive Composition H-6 material.  The United States Air Force's T-12 Cloudmaker demolition bomb (similar in design to the Grand Slam), developed after World War II, carried a heavier explosive charge than the MOAB, but was never used in combat.  In 2007, the Russian military announced that they had tested a thermobaric weapon nicknamed the "Father of All Bombs" ("FOAB"). The weapon is claimed to be four times as powerful as the MOAB, but its specifications are widely disputed.  The MOAB is the most powerful conventional bomb ever used in combat as measured by the weight of its explosive material. The explosive yield is comparable to that of the smallest tactical nuclear weapons, such as the Cold War-era American M-388 projectile fired by the portable Davy Crockett recoilless gun. The M-388, a W54 nuclear warhead variant, weighed less than 60 pounds. At the projectile's lowest yield setting of 10 tons, roughly equivalent to a single MOAB, its explosive force was only 1/144,000th (0.0007%) that of the Air Force's 1.44-megaton W49 warhead, a nuclear weapon commonly found on American ICBMs from the early 1960s.

The GBU-43/B Massive Ordnance Air Blast (MOAB, commonly known as "Mother of All Bombs") is a large-yield bomb, developed for the United States military by Albert L. Weimorts, Jr. of the Air Force Research Laboratory. At the time of development, it was said to be the most powerful non-nuclear weapon in the American arsenal. The bomb is designed to be delivered by a C-130 Hercules, primarily the MC-130E Combat Talon I or MC-130H Combat Talon II variants.


Construction.

The of a tape is the surface that can be magnetically manipulated by a tape head. This is the side that stores the information, the opposite side is simply a "substrate" to give the tape strength and flexibility. The name originates from the fact that the magnetic side of most tapes is typically made of iron oxide, though chromium is used for some tapes. An adhesive "binder" between the oxide and the substrate holds the two sides together.  In all tape formats, a tape drive uses motors to wind the tape from one reel to another, passing over tape heads to read, write or erase as it moves.

Audio recording.

Magnetic tape was invented for recording sound by Fritz Pfleumer in 1928 in Germany, based on the invention of magnetic wire recording by Oberlin Smith in 1888 and Valdemar Poulsen in 1898. Pfleumer's invention used a ferric oxide () powder coating on a long strip of paper. This invention was further developed by the German electronics company AEG, which manufactured the recording machines and BASF, which manufactured the tape. In 1933, working for AEG, Eduard Schuller developed the ring-shaped tape head. Previous head designs were needle-shaped and tended to shred the tape. Another important discovery made in this period was the technique of AC biasing, which improved the fidelity of the recorded audio signal by increasing the effective linearity of the recording medium.  Due to the escalating political tensions, and the outbreak of World War II, these developments in Germany were largely kept secret. Although the Allies knew from their monitoring of Nazi radio broadcasts that the Germans had some new form of recording technology, its nature was not discovered until the Allies acquired German recording equipment as they invaded Europe at the end of the war. It was only after the war that Americans, particularly Jack Mullin, John Herbert Orr, and Richard H. Ranger, were able to bring this technology out of Germany and develop it into commercially viable formats. Bing Crosby, an early adopter of the technology, made a large investment in the tape hardware manufacturer Ampex.  A wide variety of audio tape recorders and formats have been developed since, most significantly reel-to-reel and Compact Cassette.  Digital recording to flash memory and hard disk has largely supplanted magnetic tape for most purposes. However "tape" as a verb and as a noun has remained the common parlance for the recording process.  Some magnetic tape-based formats are listed below:

Video recording.

The practice of recording and editing audio using magnetic tape rapidly established itself as an obvious improvement over previous methods. Many saw the potential of making the same improvements in recording the video signals used by television. Video signals use more bandwidth than audio signals. Existing audio tape recorders could not practically capture a video signal. Many set to work on resolving this problem. Jack Mullin (working for Bing Crosby) and the BBC both created crude working systems that involved moving the tape across a fixed tape head at very high speeds. Neither system saw much use. It was the team at Ampex, led by Charles Ginsburg, that made the breakthrough of using a spinning recording head and normal tape speeds to achieve a very high head-to-tape speed that could record and reproduce the high bandwidth signals of video. The Ampex system was called Quadruplex and used tape, mounted on reels like audio tape, which wrote the signal in what is now called "transverse scan".  Later improvements by other companies, particularly Sony, led to the development of helical scan and the enclosure of the tape reels in an easy-to-handle videocassette cartridge. Nearly all modern videotape systems use helical scan and cartridges. Videocassette recorders used to be common in homes and television production facilities, but many functions of the VCR have been replaced with more modern technology. Since the advent of digital video and computerized video processing, optical disc media and digital video recorders can now perform the same role as videotape. These devices also offer improvements like random access to any scene in the recording and the ability to pause a live program and have replaced videotape in many situations.  Some magnetic tape-based formats are listed below:

Data storage.

Magnetic tape was first used to record computer data in 1951 on the Eckert-Mauchly UNIVAC I. The system's UNISERVO I tape drive used a thin strip of one half inch (12.65 mm) wide metal, consisting of nickel-plated bronze (called Vicalloy). Recording density was 100 characters per inch (39.37 characters/cm) on eight tracks.  Early IBM 7 track tape drives were floor-standing and used vacuum columns to mechanically buffer long U-shaped loops of tape. The two tape reels visibly fed tape through the columns, intermittently spinning 10.5 inch open reels in rapid, unsynchronized bursts, resulting in visually striking action. Stock shots of such vacuum-column tape drives in motion were widely used to represent mainframe computers in movies and television.  Most modern magnetic tape systems use reels that are much smaller than the 10.5 inch open reels and are fixed inside a cartridge to protect the tape and facilitate handling. Many late 1970s and early 1980s home computers used Compact Cassettes, encoded with the Kansas City standard, or alternate encodings. Modern cartridge formats include LTO, DLT, and DAT/DDC.  Tape remains a viable alternative to disk in some situations due to its lower cost per bit. This is a large advantage when dealing with large amounts of data. Though the areal density of tape is lower than for disk drives, the available surface area on a tape is far greater. The highest capacity tape media are generally on the same order as the largest available disk drives (about 5 TB in 2011). Tape has historically offered enough advantage in cost over disk storage to make it a viable product, particularly for backup, where media removability is necessary.  Tape has the benefit of a comparatively long duration during which the media can be guaranteed to retain the data stored on the media. Fifteen (15) to thirty (30) years of archival data storage is cited by manufacturers of modern data tape such as Linear Tape-Open media.  In 2002, Imation received a US$11.9 million grant from the U.S. National Institute of Standards and Technology for research into increasing the data capacity of magnetic tape.  In 2014, Sony and IBM announced that they had been able to record 148 gigabits per square inch with magnetic tape media developed using a new vacuum thin-film forming technology able to form extremely fine crystal particles, allowing true tape capacity of 185 TB.

Magnetic tape is a medium for magnetic recording, made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on magnetic wire recording. Devices that record and playback audio and video using magnetic tape are tape recorders and video tape recorders respectively. A device that stores computer data on magnetic tape is known as a tape drive.