The Washington Monument is an obelisk on the National Mall in Washington, D. C. built to commemorate George Washington, once commander-in-chief of the Continental Army, in the American Revolutionary War and the first President of the United States. Located due east of the Reflecting Pool and the Lincoln Memorial, the monument, made of marble and bluestone gneiss, is both the world's tallest predominantly stone structure and the world's tallest obelisk, standing 554 feet 7 11⁄32 inches tall according to the U. S. National Geodetic Survey or 555 feet 5 1⁄8 inches tall according to the National Park Service, it is the tallest monumental column in the world if all are measured above their pedestrian entrances. Overtaking the Cologne Cathedral, it was the tallest structure in the world between 1884 and 1889, after which it was overtaken by the Eiffel Tower in Paris. Construction of the monument began in 1848 and was halted for a period of 23 years, from 1854 to 1877 due to a lack of funds, a struggle for control over the Washington National Monument Society, the American Civil War.
Although the stone structure was completed in 1884, internal ironwork, the knoll, installation of memorial stones were not completed until 1888. A difference in shading of the marble, visible 150 feet or 27% up, shows where construction was halted and resumed with marble from a different source; the original design was by Robert Mills of South Carolina, but he did not include his proposed colonnade due to a lack of funds, proceeding only with a bare obelisk. The cornerstone was laid on July 4, 1848; the Washington Monument is a hollow Egyptian style stone obelisk with a 500-foot tall column surmounted by a 55-foot tall pyramidion. Its walls are 1 1⁄2 feet thick at their top; the marble pyramidion has thin walls only 7 inches thick supported by six arches, two between opposite walls that cross at the center of the pyramidion and four smaller corner arches. The top of the pyramidion is a large marble capstone with a small aluminum pyramid at its apex with inscriptions on all four sides; the lowest 150 feet of the walls, constructed during the first phase 1848–1854, are composed of a pile of bluestone gneiss rubble stones held together by a large amount of mortar with a facade of semi-finished marble stones about 1 1⁄4 feet thick.
The upper 350 feet of the walls, constructed during the second phase 1880–1884, are composed of finished marble surface stones, half of which project into the walls backed by finished granite stones. The interior is occupied by iron stairs that spiral up the walls, with an elevator in the center, each supported by four iron columns, which do not support the stone structure; the stairs contain fifty sections, most on the north and south walls, with many long landings stretching between them along the east and west walls. These landings allowed many inscribed memorial stones of various materials and sizes to be viewed while the stairs were accessible, plus one memorial stone between stairs, difficult to view; the pyramidion has eight observation windows, two per side, eight red aircraft warning lights, two per side. Two aluminum lightning rods connected via the elevator support columns to ground water protect the monument; the monument's present foundation is 37 feet thick, consisting of half of its original bluestone gneiss rubble encased in concrete.
At the northeast corner of the foundation, 21 feet below ground, is the marble cornerstone, including a zinc case filled with memorabilia. Fifty American flags fly on a large circle of poles centered on the monument. In 2001, a temporary screening facility was added to the entrance to prevent a terrorist attack. An earthquake in 2011 damaged the monument, it was closed until 2014, it was closed again for elevator system repairs, security upgrades, mitigation of soil contamination from August 2016 to September 2019. George Washington, hailed as the father of his country, as the leader, "first in war, first in peace and first in the hearts of his countrymen", was the dominant military and political leader of the new United States of America from 1775 to 1799, his former enemy King George III called him "the greatest character of the age."At his death in 1799, he left a critical legacy. Washington was the unchallenged public icon of American civic patriotism, he was identified with the Federalist Party, which lost control of the national government in 1800 to the Jeffersonian Republicans, who were reluctant to celebrate the hero of the opposition party.
Starting with victory in the Revolution, there were many proposals to build a monument to Washington, beginning with an authorization in 1783 by the old Confederation Congress to erect an equestrian statue of the General in a future American national capital city. After his December 1799 death, the United States Congress authorized a suitable memorial in the planned national capital under construction since 1791, but the decision was reversed when the Democratic-Republican Party took control of Congress in 1801 after the pivotal 1800 Election, with the first change o
Chestnut Ridge and Schellsburg Union Church and Cemetery is a historic church and cemetery in Bedford County, Pennsylvania. The church was built by members of the Reformed and Lutheran churches in 1806, it was used by both congregations until 1843, by the Reformed congregation until 1853. The first burial in the cemetery was in 1806. Workmen who were roofing the church placed; the cemetery was not formally organized until 1860, did not receive a deed to the land until 1897. The church was built of logs and in 1881 covered with weatherboarding; the weatherboarding was removed in 1935, the church was restored in the early 2000s. The church and cemetery were added to the National Register of Historic Places in 2005; the small town of Schellsburg, the Schellsburg Historic District, listed on the National Register, is about 1/4 mile to the east on U. S. 30. Official website of the Old Log Church Schellsberg Cemetery at Find A Grave Historical marker
Automotive security refers to the branch of computer security focused on the cyber risks related to the automotive context. The high number of ECUs in vehicles and, the implementation of multiple different means of communication from and towards the vehicle in a remote and wireless manner led to the necessity of a branch of cybersecurity dedicated to the threats associated with vehicles. Not to be confused with automotive safety; the implementation of multiple ECUs inside vehicles began in the early'70s thanks to the development of integrated circuits and microprocessors that made it economically feasible to produce the ECUs on a large scale. Since the number of ECUs has increased to up to 100 per vehicle; these units nowadays control everything in the vehicle, from simple tasks such as activating the wipers to more safety-related ones like brake-by-wire or ABS. Autonomous driving is strongly reliant on the implementation of new, complex ECUs such as the ADAS, alongside sensors and their control units.
Inside the vehicle, the ECUs are connected with each other through cabled or wireless communication networks, such as CAN bus, MOST bus, FlexRay or RF as in many implementations of TPMSs. It is important to notice that many of these ECUs require data received through these networks that arrive from various sensors to operate and use such data to modify the behavior of the vehicle. Since the development of cheap wireless communication technologies such as Bluetooth, LTE, Wi-Fi, RFID and similar, automotive producers and OEMs have designed ECUs that implement such technologies with the goal of improving the experience of the driver and passengers. Safety-related systems such as the OnStar from General Motors, telematic units, communication between smartphones and the vehicle's speakers through Bluetooth, Android Auto and Apple CarPlay, RKES are just examples of how the vehicle has become externally connected to devices and, in some cases, to the internet. Furthermore, since 2016, with the development and implementation in marketed vehicles of V2X technologies, the long- and short-range communication interfaces of the vehicle have become bigger.
Although the implementation of new technologies and devices improved the safety and driving experience of the vehicle, the high number of externally-communicating units inside each vehicle has led to an increment in the dimension of the attack surfaces of each vehicle. As electronic control units nowadays have the capability of modifying the behavior of the vehicle, it is necessary to ensure that an attacker cannot have the capabilities to take control of critical systems inside the vehicle. Due to this, in the last ten to fifteen years, the new concept of automotive security started to become more and more important when designing new vehicles. Threat models of the automotive world are based on both real-world and theoretically possible attacks. Most real-world attacks aim at the safety of the people in and around the car, by modifying the cyber-physical capabilities of the vehicle, while theoretical attacks have been supposed to focus on privacy-related goals, such as obtaining GPS data on the vehicle, or capturing microphone signals and similar.
Regarding the attack surfaces of the vehicle, they are divided in long-range, short-range, local attack surfaces: LTE and DSRC can be considered long-range ones, while Bluetooth and Wi-Fi are considered short-range although still wireless. USB, OBD-II and all the attack surfaces that require physical access to the car are defined as local. An attacker, able to implement the attack through a long-range surface is considered stronger and more dangerous than the one that requires physical access to the vehicle. In 2015 the possibility of attacks on vehicles on the market has been proven possible by Miller and Valasek, that managed to disrupt the driving of a Jeep Cherokee while remotely connecting to it through remote wireless communication; the most common network used in vehicles and the one, used for safety-related communication is CAN, due to its real-time properties and cheapness. For this reason the majority of real-world attacks have been implemented against ECUs connected through this type of network.
The majority of attacks demonstrated either against actual vehicles or in testbeds fall in one or more of the following categories: Sniffing in the computer security field refers to the possibility of intercepting and logging packets or more data from a network. In the case of CAN, since it is a bus network, every node listens to all communication on the network, it is useful for the attacker to read data to learn the behavior of the other nodes of the network before implementing the actual attack. The final goal of the attacker is not to sniff the data on CAN, since the packets passing on this type of network are not valuable just to read. DoS in information security is described as an attack that has the objective of making a machine or a network unavailable. DoS attacks against ECUs connected to CAN buses can be done both against the network, by abusing the arbitration protocol used by CAN to always win the arbitration, both targeting the single ECU, by abusing the error handling protocol of CAN.
In this second case the attacker flags the messages of the victim as faulty to con