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🔗 Mathematics

A hinged dissection, also known as a swing-hinged dissection or Dudeney dissection, is a kind of geometric dissection in which all of the pieces are connected into a chain by "hinged" points, such that the rearrangement from one figure to another can be carried out by swinging the chain continuously, without severing any of the connections. Typically, it is assumed that the pieces are allowed to overlap in the folding and unfolding process; this is sometimes called the "wobbly-hinged" model of hinged dissection.

🔗 Germany 🔗 Architecture 🔗 Poland

Drzymała's wagon (Polish: wóz Drzymały) was a house on wheels built by Michał Drzymała as a protest against Imperial Germany's policy of Germanization in its Polish territories. Its owner, the peasant Michał Drzymała (1857-1937), was not only able to circumvent German building regulations by moving his home every day, but with his wagon-home became a Polish folk hero during the Partitions of Poland.

In 1886, by resolution of the Prussian Landtag, a Settlement Commission had been established to encourage German settlement in the Province of Posen and West Prussia. The Commission was empowered to purchase vacant property of the Polish szlachta and sell it to approved German applicants. The Prussian government regarded this as a measure designed to counteract the German "Flight from the East" (Ostflucht) and reduce the number of Poles, who were migrating to the area in hundreds of thousands looking for work. In Polish eyes, the establishment of the Commission was an aggressive measure designed to drive Poles from their lands.

While the campaign against Polish landownership largely missed its aims, it produced a strong opposition with its own hero, Drzymała. In 1904 he purchased a plot of land in Pogradowitz in the Posen district of Bomst, but found that the newly implemented Prussian Feuerstättengesetz ("furnace law") enabled local officials to deny him as a Pole the permission to build a permanent dwelling with an oven on his land. The law considered any place of stay a house if it stayed in one place for more than 24 hours. To get around the rule, he set himself up in a former circus caravan and for several years tenaciously defied in the courts all attempts to remove him. Each day, Drzymała moved the wagon a short distance, thereby exploiting the loophole and avoiding any legal penalties, until in 1909 he was able to buy an existent farmhouse nearby.

The case attracted publicity all over Germany. The German Kulturkampf measures and the Colonization Commission ultimately succeeded in stimulating the Polish national sentiment that they had been designed to suppress.

🔗 Literature 🔗 Psychology

Oblique Strategies (subtitled Over One Hundred Worthwhile Dilemmas) is a card-based method for promoting creativity jointly created by Brian Eno and Peter Schmidt, first published in 1975. Physically, it takes the form of a deck of 7-by-9-centimetre (2.8 in × 3.5 in) printed cards in a black box. Each card offers a challenging constraint intended to help artists (particularly musicians) break creative blocks by encouraging lateral thinking.

🔗 Technology 🔗 Engineering

Overengineering (or over-engineering, or over-kill) is the act of designing a product to be more robust or have more features than often necessary for its intended use, or for a process to be unnecessarily complex or inefficient.

Overengineering is often done to increase a factor of safety, add functionality, or overcome perceived design flaws that most users would accept.

Overengineering can be desirable when safety or performance is critical (e.g. in aerospace vehicles and luxury road vehicles), or when extremely broad functionality is required (e.g. diagnostic and medical tools, power users of products), but it is generally criticized in terms of value engineering as wasteful of resources such as materials, time and money.

As a design philosophy, it is the opposite of the minimalist ethos of "less is more" (or: “worse is better”) and a disobedience of the KISS principle.

Overengineering generally occurs in high-end products or specialized markets. In one form, products are overbuilt and have performance far in excess of expected normal operation (a city car that can travel at 300 km/h, or a home video recorder with a projected lifespan of 100 years), and hence are more expensive, bulkier, and heavier than necessary. Alternatively, they may become overcomplicated – the extra functions may be unnecessary, and potentially reduce the usability of the product by overwhelming lesser experienced and technically literate end users, as in feature creep.

Overengineering can decrease the productivity of design teams, because of the need to build and maintain more features than most users need.

A related issue is market segmentation – making different products for different market segments. In this context, a particular product may be more or less suited (and thus considered over- or under-engineered) for a particular market segment.

🔗 Cats 🔗 Ships 🔗 Rodents

The ship's cat has been a common feature on many trading, exploration, and naval ships dating to ancient times. Cats have been carried on ships for many reasons, most importantly to control rodents. Vermin aboard a ship can cause damage to ropes, woodwork, and more recently, electrical wiring. Also, rodents threaten ships' stores, devour crews' foodstuff, and could cause economic damage to ships' cargo such as grain. They are also a source of disease, which is dangerous for ships that are at sea for long periods of time. Rat fleas are carriers of plague, and rats on ships were believed to be a primary vector of the Black Death.

Cats naturally attack and kill rodents, and their natural ability to adapt to new surroundings made them suitable for service on a ship. In addition, they offer companionship and a sense of home, security and camaraderie to sailors away from home.

🔗 Biography 🔗 Mathematics 🔗 Germany 🔗 Physics 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Women writers 🔗 Physics/Biographies 🔗 Toys

🔗 Biography 🔗 Biography/science and academia

Lee Felsenstein (born April 27, 1945) is an American computer engineer who played a central role in the development of personal computers. He was one of the original members of the Homebrew Computer Club and the designer of the Osborne 1, the first mass-produced portable computer.

Before the Osborne, Felsenstein designed the Intel 8080 based Sol-20 computer from Processor Technology, the PennyWhistle modem, and other early "S-100 bus" era designs. His shared-memory alphanumeric video display design, the Processor Technology VDM-1 video display module board, was widely copied and became the basis for the standard display architecture of personal computers.

Many of his designs were leaders in reducing costs of computer technologies for the purpose of making them available to large markets. His work featured a concern for the social impact of technology and was influenced by the philosophy of Ivan Illich. Felsenstein was the engineer for the Community Memory project, one of the earliest attempts to place networked computer terminals in public places to facilitate social interactions among individuals, in the era before the commercial Internet.

🔗 Java

Java Card is a software technology that allows Java-based applications (applets) to be run securely on smart cards and more generally on similar secure small memory footprint deviceswhich are called “secure elements” (SE). Today, a Secure Element is not limited to its smart cards and other removable cryptographic tokens form factors; embedded SEs soldered onto a device board and new security designs embedded into general purpose chips are also widely used. Java Card addresses this hardware fragmentation and specificities while retaining code portability brought forward by Java.

Java Card is the tiniest of Java platforms targeted for embedded devices. Java Card gives the user the ability to program the devices and make them application specific. It is widely used in different markets: wireless telecommunications within SIM cards and embedded SIM, payment within banking cards and NFC mobile payment and for identity cards, healthcare cards, and passports. Several IoT products like gateways are also using Java Card based products to secure communications with a cloud service for instance.

The first Java Card was introduced in 1996 by Schlumberger's card division which later merged with Gemplus to form Gemalto. Java Card products are based on the specifications by Sun Microsystems (later a subsidiary of Oracle Corporation). Many Java card products also rely on the GlobalPlatform specifications for the secure management of applications on the card (download, installation, personalization, deletion).

The main design goals of the Java Card technology are portability, security and backward compatibility.

🔗 Medicine 🔗 Psychology 🔗 Rodents

Rat Park was a series of studies into drug addiction conducted in the late 1970s and published between 1978 and 1981 by Canadian psychologist Bruce K. Alexander and his colleagues at Simon Fraser University in British Columbia, Canada.

Alexander's hypothesis was that drugs do not cause addiction, and that the apparent addiction to opiate drugs commonly observed in laboratory rats exposed to them is attributable to their living conditions, and not to any addictive property of the drug itself.

To test his hypothesis, Alexander built Rat Park, a large housing colony, 200 times the floor area of a standard laboratory cage. There were 16–20 rats of both sexes in residence, food, balls and wheels for play, and enough space for mating. The results of the experiment appeared to support his hypothesis.

The two major science journals, Science and Nature, rejected Alexander, Coambs, and Hadaway's first paper, which appeared instead in Psychopharmacology in 1978. The paper's publication initially attracted no response. Within a few years, Simon Fraser University withdrew Rat Park's funding.

🔗 Germany 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/Maritime warfare 🔗 Military history/World War II 🔗 Military history/German military history 🔗 Military history/European military history 🔗 Military history/British military history

Operation Sea Lion, also written as Operation Sealion (German: Unternehmen Seelöwe), was Nazi Germany's code name for the plan for an invasion of the United Kingdom during the Battle of Britain in the Second World War. Following the Battle of France, Adolf Hitler, the German Führer and Supreme Commander of the Armed Forces, hoped the British government would accept his offer to end the war, and he reluctantly considered invasion only as a last resort if all other options failed.

As a precondition, Hitler specified the achievement of both air and naval superiority over the English Channel and the proposed landing sites, but the German forces did not achieve either at any point during the war, and both the German High Command and Hitler himself had serious doubts about the prospects for success. Nevertheless, both the German Army and Navy undertook a major programme of preparations for an invasion: training troops, developing specialised weapons and equipment, and modifying transport vessels. A large number of river barges and transport ships were gathered together on the Channel coast, but with Luftwaffe aircraft losses increasing in the Battle of Britain and no sign that the Royal Air Force had been defeated, Hitler postponed Sea Lion indefinitely on 17 September 1940 and it was never put into action.