The Pentagon, in Arlington County, across the Potomac River from Washington, D. C. is the headquarters of the United States Department of Defense. As a symbol of the U. S. military, the phrase The Pentagon is used as a metonym for the Department of Defense and its leadership. The building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on September 11, 1941, the building was dedicated on January 15, 1943. General Brehon Somervell provided the major motivating power behind the project. S. Army; the Pentagon is the world's largest office building, with about 6,500,000 sq ft of space, of which 3,700,000 sq ft are used as offices. Some 23,000 military and civilian employees, another 3,000 non-defense support personnel, work in the Pentagon, it has five sides, five floors above ground, two basement levels, five ring corridors per floor with a total of 17.5 mi of corridors. The central five-acre pentagonal plaza is nicknamed "ground zero" on the presumption that it would be a prime target in a nuclear war.
On September 11, 2001 60 years after the building's construction began, American Airlines Flight 77 was hijacked and flown into the western side of the building, killing 189 people, according to the 9/11 Commission Report. It was the first significant foreign attack on Washington's governmental facilities since the city was burned by the British during the War of 1812; the Pentagon is listed on the National Register of Historic Places and is a National Historic Landmark. The Pentagon building spans 28.7 acres, includes an additional 5.1 acres as a central courtyard. Starting with the north side and moving clockwise, its five façades are the Mall Terrace Entrance façade, the River Terrace Entrance façade, the Concourse Entrance façade, the South Parking Entrance façade, the Heliport façade. On the north side of the building, the Mall Entrance, which features a portico, leads out to a 600 ft long terrace, used for ceremonies; the River Entrance, which features a portico projecting out 20 ft, is on the northeast side, overlooking the lagoon and facing Washington.
A stepped terrace on the River Entrance leads down to the lagoon. The main entrance for visitors is on the southeast side, as are the Pentagon Metro station and the bus station. There is a concourse on the southeast side of the second floor of the building, which contains a mini-shopping mall; the south parking lot adjoins the southwest facade, the west side of the Pentagon faces Washington Boulevard. The concentric rings are designated from the center out as "A" through "E". "E" Ring offices are the only ones with outside views and are occupied by senior officials. Office numbers go clockwise around each of the rings, have two parts: a nearest-corridor number followed by a bay number, so office numbers range from 100 to 1099; these corridors radiate out from the central courtyard, with corridor 1 beginning with the Concourse's south end. Each numbered radial corridor intersects with the corresponding numbered group of offices. There are a number of historical displays in the building in the "A" and "E" rings.
Floors in the Pentagon are lettered "B" for Basement and "M" for Mezzanine, both of which are below ground level. The concourse is on the second floor at the Metro entrance. Above ground floors are numbered 1 to 5. Room numbers are given as the floor, concentric ring, office number. Thus, office 2B315 is on the second floor, B ring, nearest to corridor 3. One way to get to this office would be to go to the second floor, get to the A ring, go to and take corridor 3, turn left on ring B to get to bay 15, it is possible for a person to walk between any two points in the Pentagon in less than seven minutes. The complex includes eating and exercise facilities, meditation and prayer rooms. Tours for the public were suspended after the 2001 attack. Just south of the Pentagon are Pentagon City and Crystal City, extensive shopping and high-density residential districts in Arlington. Arlington National Cemetery is to the north; the Pentagon is surrounded by the complex Pentagon road network. The Pentagon has six Washington, DC ZIP Codes.
The Secretary of Defense, the Joint Chiefs of Staff, the four service branches each have their own ZIP Code. Before the Pentagon was built, the United States Department of War was headquartered in the Munitions Building, a temporary structure erected during World War I along Constitution Avenue on the National Mall; the War Department, a civilian agency created to administer the U. S. Army, was spread out in additional temporary buildings on the National Mall, as well as dozens of other buildings in Washington, D. C. Maryland and Virginia. In the late 1930s, a new War Department Building was constructed at 21st and C Streets in Foggy Bottom but, upon completion, the new building did not solve the department's space problem and ended up being used by the Department of State; when World War II broke out in Europe, the War Department expanded in anticipation that the United States would be drawn into the conflict. Secretary of War H
An overhead projector is a variant of slide projector, used to display images to an audience.. An overhead projector works on the same principle as a 35mm slide projector, in which a focusing lens projects light from an illuminated slide onto a projection screen where a real image is formed; however some differences are necessitated by the much larger size of the transparencies used, the requirement that the transparency be placed face up. For the latter purpose, the projector includes a mirror just before or after the focusing lens to fold the optical system toward the horizontal; that mirror accomplishes a reversal of the image in order that the image projected onto the screen corresponds to that of the slide as seen by the presenter looking down at it, rather than a mirror image thereof. Therefore, the transparency is placed face up, in contrast with a 35mm slide projector or film projector where the slide's image is non-reversed on the side opposite the focusing lens; the device has sometimes been called a "Belshazzar", after Belshazzar's feast.
Because the focusing lens is much smaller than the transparency, a crucial role is played by the optical condenser which illuminates the transparency. Since this requires a large optical lens but may be of poor optical quality, a Fresnel lens is employed; the Fresnel lens is located at the glass plate on which the transparency is placed, serves to redirect most of the light hitting it into a converging cone toward the focusing lens. Without such a condenser at that point, most of the light would miss the focusing lens. Additionally, mirrors or other condensing elements below the Fresnel lens serve to increase the portion of the light bulb's output which reaches the Fresnel lens in the first place. In order to provide sufficient light on the screen, a high intensity bulb is used which must be fan cooled. Overhead projectors include a manual focusing mechanism which raises and lowers the position of the focusing lens in order to adjust the object distance to focus at the chosen image distance given the fixed focal length of the focusing lens.
This permits a range of projection distances. Increasing the projection distance increases the focusing system's magnification in order to fit the projection screen in use. Increasing the projection distance means that the same amount of light is spread over a larger screen, resulting in a dimmer image. With a change in the projection distance, the focusing must be readjusted for a sharp image. However, the condensing optics is optimized for one particular vertical position of the lens, corresponding to one projection distance. Therefore, when it is focused for a different projection distance, part of the light cone projected by the Fresnel lens towards the focusing lens misses that lens; this has the greatest effect towards the outer edges of the projected image, so that one sees either blue or brown fringing at the edge of the screen when the focus is towards an extreme. Using the projector near its recommended projection distance allows a focusing position where this is avoided and the intensity across the screen is uniform.
The lamp technology of an overhead projector is very simple compared to a modern LCD or DLP video projector. Most overheads use an high-power halogen lamp that may consume up to 750 watts. A high-flow blower is required to keep the bulb from melting due to the heat generated, this blower is on a timer that keeps it running for a period after the light is extinguished. Further, the intense heat accelerates failure of the high intensity lamp burning out in less than 100 hours, requiring replacement. In contrast, a modern LCD or DLP projector uses an arc lamp which has a higher luminous efficacy and lasts for thousands of hours. A drawback of that technology is the warm up time required for arc lamps. Older overhead projectors used a tubular quartz bulb, mounted above a bowl-shaped polished reflector. However, because the lamp was suspended above and outside the reflector, a large amount of light was cast to the sides inside the projector body, wasted, thus requiring a higher power lamp for sufficient screen illumination.
More modern overhead projectors use an integrated lamp and conical reflector assembly, allowing the lamp to be located deep within the reflector and sending a greater portion of its light towards the Fresnel lens. A useful innovation for overhead projectors with integrated lamps/reflectors is the quick-swap dual-lamp control, allowing two lamps to be installed in the projector in movable sockets. If one lamp fails during a presentation the presenter can move a lever to slide the spare into position and continue with the presentation, without needing to open the projection unit or waiting for the failed bulb to cool before replacing it; some ancient projectors like the magic lantern can be regarded as predecessors of the overhead projector. The steganographic mirror came closest to how the o
Bern or Berne is the de facto capital of Switzerland, referred to by the Swiss as their "federal city", in German Bundesstadt, French Ville Fédérale, Italian Città Federale. With a population of 142,493, Bern is the fifth-most populous city in Switzerland; the Bern agglomeration, which includes 36 municipalities, had a population of 406,900 in 2014. The metropolitan area had a population of 660,000 in 2000. Bern is the capital of the canton of Bern, the second-most populous of Switzerland's cantons; the official language in Bern is German, but the most-spoken language is an Alemannic Swiss German dialect, Bernese German. In 1983, the historic old town in the centre of Bern became a UNESCO World Heritage Site; the etymology of the name "Bern" is uncertain. According to the local legend, based on folk etymology, Berchtold V, Duke of Zähringen, the founder of the city of Bern, vowed to name the city after the first animal he met on the hunt, this turned out to be a bear, it has long been considered that the city was named after the Italian city of Verona, which at the time was known as Bern in Middle High German.
As a result of the finding of the Bern zinc tablet in the 1980s, it is now more common to assume that the city was named after a pre-existing toponym of Celtic origin *berna "cleft". The bear was the heraldic animal of the coat of arms of Bern from at least the 1220s; the earliest reference to the keeping of live bears in the Bärengraben dates to the 1440s. No archaeological evidence that indicates a settlement on the site of today′s city centre prior to the 12th century has been found so far. In antiquity, a Celtic oppidum stood on the Engehalbinsel north of Bern, fortified since the second century BC, thought to be one of the 12 oppida of the Helvetii mentioned by Caesar. During the Roman era, a Gallo-Roman vicus was on the same site; the Bern zinc tablet has the name Brenodor. In the Early Middle Ages, a settlement in Bümpliz, now a city district of Bern, was some 4 km from the medieval city; the medieval city is a foundation of the Zähringer ruling family, which rose to power in Upper Burgundy in the 12th century.
According to 14th-century historiography, Bern was founded in 1191 by Duke of Zähringen. In 1218, after Berthold died without an heir, Bern was made a free imperial city by the Goldene Handfeste of Holy Roman Emperor Frederick II. In 1353, Bern joined the Swiss Confederacy, becoming one of the eight cantons of the formative period of 1353 to 1481. Bern invaded and conquered Aargau in 1415 and Vaud in 1536, as well as other smaller territories, thereby becoming the largest city-state north of the Alps; the city grew out towards the west of the boundaries of the peninsula formed by the river Aare. The Zytglogge tower marked the western boundary of the city from 1191 until 1256, when the Käfigturm took over this role until 1345, it was, in turn, succeeded by the Christoffelturm until 1622. During the time of the Thirty Years' War, two new fortifications – the so-called big and small Schanze – were built to protect the whole area of the peninsula. After a major blaze in 1405, the city's original wooden buildings were replaced by half-timbered houses and subsequently the sandstone buildings which came to be characteristic for the Old Town.
Despite the waves of pestilence that hit Europe in the 14th century, the city continued to grow due to immigration from the surrounding countryside. Bern was occupied by French troops in 1798 during the French Revolutionary Wars, when it was stripped of parts of its territories, it regained control of the Bernese Oberland in 1802, following the Congress of Vienna of 1814, it newly acquired the Bernese Jura. At this time, it once again became the largest canton of the Confederacy as it stood during the Restoration and until the secession of the canton of Jura in 1979. Bern was made the Federal City within the new Swiss federal state in 1848. A number of congresses of the socialist First and Second Internationals were held in Bern during World War I when Switzerland was neutral; the city's population rose from about 5,000 in the 15th century to about 12,000 by 1800 and to above 60,000 by 1900, passing the 100,000 mark during the 1920s. Population peaked during the 1960s at 165,000 and has since decreased to below 130,000 by 2000.
As of September 2017, the resident population stood at 142,349, of which 100,000 were Swiss citizens and 42,349 resident foreigners. A further estimated 350,000 people live in the immediate urban agglomeration. Bern lies on the Swiss plateau in the canton of Bern west of the centre of Switzerland and 20 km north of the Bernese Alps; the countryside around Bern was formed by glaciers during the most recent ice age. The two mountains closest to Bern are Gurten with a height of 864 m and Bantiger with a height of 947 m; the site of the old observatory in Bern is the point of origin of the CH1903 coordinate system at 46°57′08.66″N 7°26′22.50″E. The city was built on a hilly peninsula surrounded by the river Aare, but outgrew natural boundaries by the 19th century. A number of bridges have been built to allow the city to expand beyond the Aare. Bern is built on uneven ground. An elevation difference of several metres exists betwe
Bandaranaike Memorial International Conference Hall
The Bandaranaike Memorial International Conference Hall, is a convention center located in Colombo, Sri Lanka. Built between 1970 and 1973, the convention centre was a gift from the People's Republic of China in memory of Solomon Ridgeway Dias Bandaranaike, Prime Minister; the construction of the hall was carried out by a joint Sri Lankan and Chinese workforce with a considerable portion of the building materials being imported from China. In 1998 a small Exhibition Centre, the Sirimavo Bandaranaike Memorial Exhibition Centre, was built on the grounds as a gift from China; the BMICH premises is managed by the S. W. R. D. Bandaranaike National Memorial Foundation, chaired by the President of Sri Lanka; the BNMF has an academic wing specialised in International Relations and Cultural Studies named "Bandaranaike Centre for International Studies" located within the BMICH premises. The building has over 1,500 m2 of floorspace, is located in the Cinnamon Gardens area of Colombo. An up-to-date library with volumes of literature on all subjects is available for the use of research for delegates visiting the BMICH.
To facilitate with banking needs, a bank is located near the main hall. Due to the high-profile events taking place within the venue the Sri Lanka Police maintains a permanent detachment and the Mount Lavinia Hotel has a restaurant; the Sirimavo Bandaranaike Memorial Exhibition Centre has floor area covering 4,500 sq. m. consists of two exhibition halls, dining room, lounge and other VIP amenities. Several high-profile events and exhibitions have been held in the venue, including the Non-Aligned Movement Summit 16-19 August 1976, Commonwealth Heads of Government Meeting 2013, the WORLD CONFERENCE ON YOUTH 2014, it is host to the annual EDEX Expo. There have been some local events and exhibitions held in Sirimavo Bandaranaike Memorial Exhibition Centre such as BMICH Life Style Shopping Expo Colombo International Book Fair Wedding Show Bridal show Pro Food Facets Gem Motor show Build SL Kedella Architect Found within the large grounds are several government and private organisations; these include: Bandaranaike International Diplomatic Training Institute Bandaranaike Centre for International Studies LankaCert - Computer Emergency Response Team of the Sri Lankan Government National Police Commission Rakna Arakshaka Lanka Security Ltd.
Official Website Conference & Banquet facilities available at the Bandaranaike Memorial International Conference Hall
A meeting is when two or more people come together to discuss one or more topics in a formal or business setting, but meetings occur in a variety of other environments. Many various types of meetings exist. A meeting is a gathering of two or more people, convened for the purpose of achieving a common goal through verbal interaction, such as sharing information or reaching agreement. Meetings may occur face-to-face or as mediated by communications technology, such as a telephone conference call, a skyped conference call or a videoconference. One Merriam-Webster dictionary defines a meeting as "an act or process of coming together" - for example "as an assembly for a common purpose ". Meeting planners and other meeting professionals may use the term "meeting" to denote an event booked at a hotel, convention center or any other venue dedicated to such gatherings; the term "meeting" may refer to a lecture, conference, exhibition or trade show, training course, team-building session and kick-off event.
Common types of meeting include: Committee meeting, a coming-together of a defined subset of an organization Investigative meeting when conducting a pre-interview, exit interview or a meeting among the investigator and representative Kickoff meeting, the first meeting with a project team and the client of the project to discuss the role of each team-member Town hall meeting, an informal public gathering. Work meeting, which produces a product or intangible result such as a decision. Board meeting, a meeting of the board of directors of an organization Management meeting, a meeting among managers Staff meeting a meeting between a manager and those that report to that manager Team meeting, in project contexts - a meeting among colleagues working on various aspects of a team project. Other varieties include breakfast meetings off-site meetings, "stand-up meetings" where participants stand up to encourage brevity. Since a meeting can be held once or the meeting organizer has to determine the repetition and frequency of occurrence of the meeting: one-time， recurring meeting， or a series meeting such as a monthly "lunch and learn" event at a company, club or organization in which the placeholder is the same, but the agenda and topics to be covered vary.
In Russian, a "flying meeting" is a hastily-called brief meeting. Johansen, Robert. "Electronic Meetings: Technical Alternatives". ACM Digital Library. Retrieved October 1, 2018. Olson, Gary M.. "Small group design meetings: an analysis of collaboration". Human-Computer Interaction. 7: 347–374. Doi:10.1207/s15327051hci0704_1. ISSN 0737-0024. Retrieved October 1, 2018. Effective Meetings at Work. Taylor & Francis. 2007. ISBN 978-1-136-40844-1. Retrieved October 1, 2018. 112 pages
An aircraft is a machine, able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, airships and hot air balloons; the human activity that surrounds aircraft is called aviation. The science of aviation, including designing and building aircraft, is called aeronautics. Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion and others. Flying model craft and stories of manned flight go back many centuries, however the first manned ascent – and safe descent – in modern times took place by larger hot-air balloons developed in the 18th century; each of the two World Wars led to great technical advances. The history of aircraft can be divided into five eras: Pioneers of flight, from the earliest experiments to 1914.
First World War, 1914 to 1918. Aviation between the World Wars, 1918 to 1939. Second World War, 1939 to 1945. Postwar era called the jet age, 1945 to the present day. Aerostats use buoyancy to float in the air in much the same way, they are characterized by one or more large gasbags or canopies, filled with a low-density gas such as helium, hydrogen, or hot air, less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, it adds up to the same weight as the air that the craft displaces. Small hot-air balloons called sky lanterns were first invented in ancient China prior to the 3rd century BC and used in cultural celebrations, were only the second type of aircraft to fly, the first being kites which were first invented in ancient China over two thousand years ago. A balloon was any aerostat, while the term airship was used for large, powered aircraft designs – fixed-wing. In 1919 Frederick Handley Page was reported as referring to "ships of the air," with smaller passenger types as "Air yachts."
In the 1930s, large intercontinental flying boats were sometimes referred to as "ships of the air" or "flying-ships". – though none had yet been built. The advent of powered balloons, called dirigible balloons, of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid outer framework and separate aerodynamic skin surrounding the gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat and an "airship" is a powered one. A powered, steerable aerostat is called a dirigible. Sometimes this term is applied only to non-rigid balloons, sometimes dirigible balloon is regarded as the definition of an airship.
Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as blimps. During the Second World War, this shape was adopted for tethered balloons; the nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered. Heavier-than-air aircraft, such as airplanes, must find some way to push air or gas downwards, so that a reaction occurs to push the aircraft upwards; this dynamic movement through the air is the origin of the term aerodyne. There are two ways to produce dynamic upthrust: aerodynamic lift, powered lift in the form of engine thrust. Aerodynamic lift involving wings is the most common, with fixed-wing aircraft being kept in the air by the forward movement of wings, rotorcraft by spinning wing-shaped rotors sometimes called rotary wings. A wing is a flat, horizontal surface shaped in cross-section as an aerofoil. To fly, air must generate lift.
A flexible wing is a wing made of fabric or thin sheet material stretched over a rigid frame. A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary. With powered lift, the aircraft directs its engine thrust vertically downward. V/STOL aircraft, such as the Harrier Jump Jet and F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. A pure rocket is not regarded as an aerodyne, because it does not depend on the air for its lift. Rocket-powered missiles that obtain aerodynamic lift at high speed due to airflow over their bodies are a marginal case; the forerunner of the fixed-wing aircraft is the kite. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly, were invented in China around 500 BC.
Much aerodynamic research was done with kites before test aircraft, wind tunnels, computer modelling programs became available. The first heavier-than-air craft capable of controlled free-flight were gliders. A glider designed by Geo
Sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is used to enhance or alter the sound of the sources on the stage by using electronic effects, such as reverb, as opposed to amplifying the sources unaltered. A sound reinforcement system for a rock concert in a stadium may be complex, including hundreds of microphones, complex live sound mixing and signal processing systems, tens of thousands of watts of amplifier power, multiple loudspeaker arrays, all overseen by a team of audio engineers and technicians. On the other hand, a sound reinforcement system can be as simple as a small public address system, consisting of, for example, a single microphone connected to a 100 watt amplified loudspeaker for a singer-guitarist playing in a small coffeehouse.
In both cases, these systems reinforce sound to distribute it to a wider audience. Some audio engineers and others in the professional audio industry disagree over whether these audio systems should be called sound reinforcement systems or PA systems. Distinguishing between the two terms by technology and capability is common, while others distinguish by intended use. In some regions or markets, the distinction between the two terms is important, though the terms are considered interchangeable in many professional circles. A typical sound reinforcement system consists of; these primary parts involve varying numbers of individual components to achieve the desired goal of reinforcing and clarifying the sound to the audience, performers, or other individuals. Sound reinforcement in a large format system involves a signal path that starts with the signal inputs, which may be instrument pickups or a microphone that a vocalist is singing into or a microphone placed in front of an instrument or guitar amplifier.
These signal inputs are plugged into the input jacks of a thick multicore cable. The snake delivers the signals of all of the inputs to one or more mixing consoles. In a coffeehouse or small nightclub, the snake may be only routed to a single mixing console, which an audio engineer will use to adjust the sound and volume of the onstage vocals and instruments that the audience hears through the main speakers and adjust the volume of the monitor speakers that are aimed at the performers. Mid- to large-size performing venues route the onstage signals to two mixing consoles: the front of house, the stage monitor system, a second mixer at the side of the stage. In these cases, at least two audio engineers are required. Once the signal arrives at an input on a mixing console, this signal can be adjusted in many ways by the sound engineer. A signal can be compressed, or panned; the signal may be routed into an external effects processor, such as a reverb effect, which outputs a wet version of the signal, mixed in varying amounts with the dry signal.
Many electronic effects units are used in sound reinforcement systems, including digital delay and reverb. Some concerts use pitch correction effects. Mixing consoles have additional sends referred to as auxes or aux sends, on each input channel so that a different mix can be created and sent elsewhere for another purpose. One usage for aux sends. Another use of an aux send is to select varying amounts of certain channels, route these signals to an effects processor. A common example of the second use of aux sends is to send all of the vocal signals from a rock band through a reverb effect. While reverb is added to vocals in the main mix, it is not added to electric bass and other rhythm section instruments; the processed input signals are mixed to the master faders on the console. The next step in the signal path depends on the size of the system in place. In smaller systems, the main outputs are sent to an additional equalizer, or directly to a power amplifier, with one or more loudspeakers that are connected to that amplifier.
In large-format systems, the signal is first routed through an equalizer to a crossover. A crossover splits the signal into multiple frequency bands with each band being sent to