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Software-defined radio

Software-defined radio is a radio communication system where components that have been traditionally implemented in hardware are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the evolving capabilities of digital electronics render practical many processes which were once only theoretically possible. A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware; such a design produces a radio which can receive and transmit different radio protocols based on the software used. Software radios have significant utility for the military and cell phone services, both of which must serve a wide variety of changing radio protocols in real time. In the long term, software-defined radios are expected by proponents like the SDRForum to become the dominant technology in radio communications.

SDRs, along with software defined. A software-defined radio can be flexible enough to avoid the "limited spectrum" assumptions of designers of previous kinds of radios, in one or more ways including: Spread spectrum and ultrawideband techniques allow several transmitters to transmit in the same place on the same frequency with little interference combined with one or more error detection and correction techniques to fix all the errors caused by that interference. Software defined antennas adaptively "lock onto" a directional signal, so that receivers can better reject interference from other directions, allowing it to detect fainter transmissions. Cognitive radio techniques: each radio measures the spectrum in use and communicates that information to other cooperating radios, so that transmitters can avoid mutual interference by selecting unused frequencies. Alternatively, each radio connects to a geolocation database to obtain information about the spectrum occupancy in its location and, adjusts its operating frequency and/or transmit power not to cause interference to other wireless services.

Dynamic transmitter power adjustment, based on information communicated from the receivers, lowering transmit power to the minimum necessary, reducing the near-far problem and reducing interference to others, extending battery life in portable equipment. Wireless mesh network where every added radio increases total capacity and reduces the power required at any one node; each node transmits using only enough power needed for the message to hop to the nearest node in that direction, reducing the near-far problem and reducing interference to others. The ideal receiver scheme would be to attach an analog-to-digital converter to an antenna. A digital signal processor would read the converter, its software would transform the stream of data from the converter to any other form the application requires. An ideal transmitter would be similar. A digital signal processor would generate a stream of numbers; these would be sent to a digital-to-analog converter connected to a radio antenna. The ideal scheme is not realizable due to the current limits of the technology.

The main problem in both directions is the difficulty of conversion between the digital and the analog domains at a high enough rate and a high enough accuracy at the same time, without relying upon physical processes like interference and electromagnetic resonance for assistance. Most superheterodyne receivers use a variable-frequency oscillator and filter to tune the desired signal to a common intermediate frequency or baseband, where it is sampled by the analog-to-digital converter. However, in some applications it is not necessary to tune the signal to an intermediate frequency and the radio frequency signal is directly sampled by the analog-to-digital converter. Real analog-to-digital converters lack the dynamic range to pick up sub-microvolt, nanowatt-power radio signals. Therefore, a low-noise amplifier must precede the conversion step and this device introduces its own problems. For example, if spurious signals are present, these compete with the desired signals within the amplifier's dynamic range.

They may block them completely. The standard solution is to put band-pass filters between the antenna and the amplifier, but these reduce the radio's flexibility. Real software radios have two or three analog channel filters with different bandwidths that are switched in and out; the term "digital receiver" was coined in 1970 by a researcher at a United States Department of Defense laboratory. A laboratory called the Gold Room at TRW in California created a software baseband analysis tool called Midas, which had its operation defined in software; the term "software radio" was coined in 1984 by a team at the Garland, Division of E-Systems Inc. to refer to a digital baseband receiver and published in their E-Team company newsletter. A'Software Radio Proof-of-Concept' laboratory was developed by the E-Systems team that popularized Software Radio within various government agencies; this 1984 Software Radio was a digital baseband receiver that provided programmable interference cancellation and demodulation for broadband signals with thousands of adaptive filter taps, using multiple array processors accessing shared memory.

In 1991, Joe Mitola independently reinvented the term software radio for a plan to build a GSM base

Da la Vuelta

"Da la Vuelta" is a song written by Emilio Estefan and Kike Santander and performed by American singer Marc Anthony. Produced by Anthony, Ángel "Cucco" Peña, it is a salsa track which deals with the singer letting go of his former lover, it is one of the three Spanish-language songs to be included on Anthony's 1999 self-titled album and was released as a promotional single in the same year. Despite the album being met with unfavorable reviews, "Da la Vuelta" garnered positive reactions from music critics who praised it as a danceable number; the record received a Latin Grammy nomination for Best Tropical Song in 2000 and was nominated for Tropical Song of the Year at the Lo Nuestro Awards the following year. Commercially, it reached number 22 and number six on the Billboard Hot Latin Songs and Tropical Songs charts in the United States respectively. "Da la Vuelta" is a salsa track composed by Emilio Estefan and Kike Santander and produced by Anthony, Ángel "Cucco" Peña. Peña had collaborated with Anthony as a producer for his third studio album Contra la Corriente in 1997.

It is one of the three Spanish-language records included on Marc Anthony along with the Spanish-language versions of "I Need to Know" and "She's Been Good to Me". The song begins as a "soft ballad" with a bolero guitar and mariachi horn arrangements before transitioning into a salsa number. Lyrically, it is about the singer letting go of his former lover. "Da la Vuelta" was released as a promotional single for the album in 1999. Anthony performed; the Richmond Times-Dispatch journalist Melissa Ruggierit called "Da la Vuelta" a "traditional romp co-written by Emilio Estefan, a scorcher." Chloe Cabrera of The Tampa Tribune felt that "Da la Vuelta", along with "Dímelo", has "the feel of his Grammy-award winning 1997 album, Contra la Corriente." Mario Tarradell, who gave Marc Anthony a negative review on The Dallas Morning News, lamented that the record was filled with ballads instead of dance numbers like "Da la Vuelta", "Dímelo", "That's Okay". However, he remarked that "we know he can do the salsa stuff" and insisted that they were "not a challenge" for Anthony.

Parry Gettelman, who wrote an unfavorable review of the album, mentioned that "Da la Vuelta" was "certainly worthy of Anthony's voice." The Dayton Daily News editor Sofia Villalobos opined that the track "combines an older, Tito Puente style with the latest fads of the aforementioned Lopez. The San Diego Union-Tribune writer Ernesto Portillo, Jr. called it a "danceable salsa number" while Rueben Rosario highlighted the record as "hip-grinding" and "vintage Anthony" on St. Paul Pioneer Press. Grace Bastidas of The Village Voice praised it as a "beautiful little letting-go number"."Da la Vuelta" received a nomination for Best Tropical Song at the inaugural Latin Grammy Awards in 2000, awarded to "El Niágara en Bicicleta" by Juan Luis Guerra. It was nominated Tropical Song of the Year at the 13th Annual Lo Nuestro Awards in 2001 but lost to "A Puro Dolor" by Son by Four. Santander and Estefan were presented with a BMI Latin Award in 2001 as it was recognized as the one of the best-performing songs of the year.

The track was included on Anthony's greatest hits album Sigo Siendo Yo: Grandes Exitos. Commercially, "Da la Vuelta" peaked at number 22 on the Billboard Hot Latin Songs chart in the United States, it fared better on the Billboard Latin Tropical Songs chart by reaching number 6 and ended 2000 as the ninth best-performing tropical song of the year in the country. Credits adapted from the Marc Anthony liner notes. Lyrics of this song at MetroLyrics

Nigel Melker

Nigel Melker is a Dutch racing driver. Melker was born in Rotterdam, he began his motorsport career in winning in the Dutch Mini Junior Cup. In 2005, he won the German Junior championship and finishing as runner-up in the European ICA Junior championship. After sitting out the 2007 season, Melker moved up to single-seaters in 2008, he participated in the Formula Renault 2.0 Northern European Cup with Van Amersfoort Racing. He finished in twelfth place in the standings with eleven point-scoring positions that gave him 120 points, he took part in ten races of the Italian Formula Renault Championship. He finished eighteenth with 37 points; the following season, Melker competed in both the Formula Renault 2.0 Northern European Cup and Eurocup Formula Renault 2.0 championships with MP Motorsport. He finished eighteenth in the NEC standings, taking points in all six races he contested. In the Eurocup, he took part in the first five rounds, finishing 23rd with five points for sixth place at Spa. In 2010, Melker became the first driver to join RSC Mücke Motorsport for the 2010 GP3 Series season.

His team-mates were German Tobias Hegewald. He started the season by taking the first pole position of his open-wheel racing career in the opening round at Barcelona, but in the race he was involved in an accident on the opening lap and retired. In the sprint race he rose to fourteenth place, he took another pole in Turkey, but did not finish in the points until the final race of the season at Monza, restricting him to 23rd place in the championships. Melker remained in GP3 with the Mücke team for the 2011 season, alongside Michael Christensen and Luciano Bacheta. With the benefit of a year's experience in the category, his form was much stronger and he won the first race of the season in Turkey; this gave him the early championship lead, he took a further four podium finishes, but he slipped to third place behind the Lotus ART duo of Valtteri Bottas and James Calado after his team appeared to lose its competitive edge following mid-season testing at Barcelona. As well as his 2011 GP3 campaign, Melker competed in the season's Formula 3 Euro Series with Mücke, finishing in fourth position in the drivers' standings with four wins.

He finished ahead of his team-mates Felix Rosenqvist, Marco Sørensen and Facu Regalia, but was unable to challenge dominant champion Roberto Merhi, his Prema Powerteam colleague Daniel Juncadella, or Signature driver Marco Wittmann. After participating in the non-championship 2011 GP2 Final with DAMS, Melker switched to Ocean Racing Technology for the 2012 season alongside Jon Lancaster. With a best race finish of fourth at Silverstone, he ended the season 19th in the championship. Melker made his racing début in a Formula Renault 3.5 car at Silverstone 2012, replacing César Ramos at the Lotus team. He qualified a respectable 14th for the first race and went on to take a podium at his first race at a wet racing track, finishing 3rd, he retired in the second race and was replaced by Estonian Kevin Korjus for the remainder of the season. He was the only driver in Lotus car #11 to get a podium that year. After a disappointing season in GP2, Melker went to Formula Renault 3.5 full-time for 2013, driving for previous year's team champions Tech 1 Racing alongside series veteran Mikhail Aleshin.

Melker spent most of the season in the subtop of the championship, amassing 4 podiums and 136 points, as well as posting 2 fastest laps. His best weekend of the season was at the Red Bull Ring when he was runner-up twice behind dominant winner Marco Sørensen, he finished the season in 6th place. Unable to find a drive in Formula Renault 3.5 for 2014, Melker turned his attention elsewhere. He signed with Azerti Motorsport for the inaugural Formula Acceleration 1 season, he was competitive finishing second twice at the opening round in Portugal, before taking a double victory at Circuito de Navarra. He went on to win the drivers' championship after a victory at the Nürburgring and a double victory at Assen. † – As Melker was a guest driver, he was ineligible for points. Official site Melker career statistics at Driver Database Nigel Melker on Twitter

Valley of the Dinosaurs, ParaĆ­ba

The Valley of the Dinosaurs is an area in the state of Paraíba, that contains many fossilized dinosaur tracks. It contains the Valley of the Dinosaurs Area of Relevant Ecological Interest, a sustainable use area of relevant ecological interest; this in turn contains the smaller and protected Valley of the Dinosaurs Natural Monument. In 2015–16 there was concern that renovations to the tourist attraction, delayed through lack of funding, might not be respecting the integrity of the site; the Valley of the Dinosaurs is an area in the sedimentary basin of the Peixe River that holds over 50 types of ancient animal tracks, including those of stegosaurus and iguanodons. The valley covers an area of about 700 square kilometres that includes the city of Sousa, Paraíba, ten other municipalities, it is in a Caatinga biome. Tracks have been found in about 30 locations in the valley, with fossilized footprints of over 80 species at about 20 different stratographic levels. Most of the tracks are of carnivorous dinosaurs.

The tracks the dinosaurs made in the damp earth beside ponds and rivers in rainy periods hardened over long periods of drought, gained new layers of sand and clay from floods, fossilized. Footprints are as small as 5 centimetres from dinosaurs the size of modern chickens, up to 40 centimetres long, such as that of a four-ton iguanodon; the most visited site is the island called the Passagem das Pedras in the bed of the Peixe River. This is about 7 kilometres from the urban centre of Sousa; the dinosaur tracks were discovered by a local farmer, Anísio Fausto Silva, in the late 19th century. At the start of the 20th century the engineer Luciano Jacques de Moraes began to study them scientifically. Although not a trained palaeontologist, Moraes gave detailed descriptions with drawings of the tracks for publication in the book Serras e Montanhas do Nordeste; the Área de Relevante Interesse Ecológico Vale dos Dinossauros was established on 18 December 1984 and is administered by the Chico Mendes Institute for Biodiversity Conservation.

The protected area covers 145.79 hectares. It is in the Sousa municipality of the state of Paraíba; the Valley of the Dinosaurs Natural Monument was created in 2002 by the municipality of Souza. This is a protected natural monument of about 40 hectares. There were plans to divert the Peixe River. A R$1.3 million renovation was funded by the federal government and Petrobras, the site was reopened on 24 May 2013. Work included renovation of the museum, restructuring of the exhibition space, auditorium and bathrooms, changes to the external area including delimitation of parking spaces, paving of paths and walkways and upgrades to lookout gazebos to meet accessibility standards. Suspended walkways let the visitors view 50 fossilized footprints of the carnivorous noasauridae and 53 of the herbivore Iguanodon; the Area of Relevant Ecological Interest is classed as IUCN protected area category IV, whose purpose is to maintain natural ecosystems of regional or local importance and regulate use of these areas to make it compatible with the nature conservation objectives.

In December 2015 it was reported that the Valley of the Dinosaurs was in a state of neglect, renovations had been suspended. The replica of Tyrannosaurus Rex had been destroyed, access roads were covered by scrub, there were hundreds of cobblestones around the entrance, piles of sand and other problems. Reporters found that the work had been abandoned due to delays in releasing funding to the company charged with work on the site. In February 2016 the Federal Public Ministry in Sousa recommended that Paraíba Office of Environment Administration prepare the management plan for the natural monument within 90 days defining steps to ensure the integrity and protection of natural resources of the site, steps taken to integrate it into the social and economic life of the surrounding communities; the MPF recommended that SUDEMA give a detailed report within 30 days on the work carried out by the Sousa Prefecture in the Valley of Dinosaurs, which should be limited to protecting the integrity of the unit.

If the prefecture's work was not limited to this, MPF said that SUDEMA should take administrative measures to stop the work

Resaca, Georgia

Resaca is a town in Gordon County, United States, with unincorporated areas extending into Whitfield County. Resaca lies along the Oostanaula River; the population was 544 at the 2010 census. It is home to a monastery. Resaca is located at 34°34′45″N 84°56′38″W. According to the United States Census Bureau, the town has a total area of 2.9 square miles, of which 2.8 square miles is land and 0.1 square miles is water. Resaca known as Dublin, was founded in 1848 with the arrival of the Western and Atlantic Railroad into the area. Dublin was renamed Resacca when it was incorporated as a town in 1854. In 1871, the spelling of the town was shortened to its present form of Resaca; the town was named by returning Mexican–American War inductees who fought at the Battle of Resaca de la Palma in Brownsville, Texas, in 1846. The Civil War Battle of Resaca was fought in and around Resaca in May 1864; each year a re-enactment of the Battle of Resaca, the first battle of the Atlanta Campaign, is held on the third weekend of May.

Resaca is the location of the first Confederate cemetery in the state of Georgia. The story of the cemetery is:The memory of a Georgia woman, Mary J. Green, who with her own hands gathered and interred the bones and bodies of the Confederate dead left lying on the Resaca Battlefield, should always be sacred to us; the sight that greeted the Green family when they returned to their plantation after the battle was more than they could bear. Around the house on all sides were scattered graves of Confederates, buried where they fell; the Green daughters conceived the idea of collecting all the bodies and re-interring them in a plot of land to be known as a Confederate cemetery. The one great drawback, was that they had no money. In the summer of 1866, Mary began writing to her friends around the state, begging them to try and raise money for the cemetery. Although poverty was rampant in the South, the citizenry responded by giving what they could, be it a nickel, a dime, a quarter, or a dollar. Col. Green gave his daughters 2.5 acres of land with rustic bridges spanning the stream through the grounds of their cemetery.

The account of the first Memorial Day, October 25, 1866, written by Mary Green: "The day selected for the dedication... was bright and beautiful, one of those charming days of our Indian summers where no sound was heard save the fluttering of falling leaves – a suitable accompaniment to our sad thoughts, as we stood in the'bivouac of the dead.'" This cemetery and one at Winchester, were consecrated and dedicated on the same day, each sponsoring group thinking theirs was the first Confederate Cemetery. Mathew Brady captured several photographs of the battlefield. Scenes of the conflict and.its aftermath were depicted by various artists including Adolph Metzner. The Town of Resaca was incorporated and granted a charter by the State of Georgia in 1981. Resacas are former channels of the Rio Grande. There are two explanations for the origin of the word "resaca." The less holds that it is a contraction of Spanish rio seco. The other is that the word stems from the Spanish resacar, since the primary geological function of a resaca seems to be diversion and dissipation of floodwater from the river.

Resacas are cut off from the river, having no inlet or outlet. Vernacular northern Mexican and other Latin American Spanish dialects translate'resaca' as'hangover' - undoubtedly referencing the dry cotton-mouth condition the morning after heavy alcohol consumption - as a'dry river bed.' Anecdotes abound as to the derivation of the place name, one involving the capture of an Indian maiden by settlers to be offered in marriage to the single man of her choosing. Transported by her captors to the center of the settlement in a gunnysack, she was ceremoniously unveiled to the awaiting public. Upon seeing her in the sunlight, onlookers were aghast at her homeliness, whereupon chants of "Re-sack-'er" arose. Since 1977, the Resaca area has been the home of the Monastery of the Glorious Ascension, housed in the former midcentury modern hilltop residence purchased from the late Thurman Chitwood, local entrepreneur and ordained minister in the Church of Christ; the monastery is the only Orthodox Christian monastery in the state of Georgia.

At one time it offered hospice to those afflicted with AIDS. Local detractors, with unfounded fears of casual communicability of AIDS, unsuccessfully sought to have its permitting revoked; the monastery, just across the line in Whitfield County, maintains a cemetery for Orthodox Christians. It has been under the authority of various "national" jurisdictions, not uncommon for an Orthodox monastery, it is part or the Russian Orthodox Church Outside of Russia. The Abbot is Archimandrite Maximos Weimar The Resaca Beach Poster Girl Contest, a swimsuit pageant at one time known throughout the South, was founded in the nearby city of Dalton in 1983 as a marketing gimmick of Conquest Carpet Mills, Inc; the name is tongue-in-cheek, since there is no ocean for hundreds of miles, although it draws reference to a once popular bathing spot on the Oostanaula riverbank deemed Resaca Beach. Local boosterism proclaims: "Resaca Beach – North Georgia's Gateway to the Gulf." The pageant, which launched the career of Whitfield County native Marla Maples, former spouse of real estate magnate Donald Trump, has been held intermittently since the mid-1980s, most in 2008.

As of the census of 2000, there were 815 people, 263 households, 189 families residing in the city. The population density was 295.4 people per square mile. There

MusaNet

MusaNet is a global network of scientists and other stakeholders working on banana genetic resources. Founded in 2011 and coordinated by Bioversity International, it has over 100 individual members representing various banana research institutes and organizations. MusaNet aims to optimize the conservation and use of Musa genetic resources by coordinating and strengthening the conservation and related research efforts of a worldwide network of public and private sector stakeholders; the vision of MusaNet is a world in which Musa genetic diversity is valued and supporting all life. The mission of MusaNet is To build upon existing strengths in the global and national collections by bringing people to optimize the effort to conserve, add value and promote the use and safe distribution of a wide range of Musa genetic diversity as a foundation for further breeding or direct use by farmers. MusaNet is committed to overseeing the further development and monitoring of the implementation of The Global Strategy for the Conservation and Use of Musa Genetic Resources by meeting the following objectives: Ensure the secured conservation of the entire Musa genepool by assessing the diversity conserved and filling gaps in collections, with an emphasis on threatened material.

Strengthen the capacity of partners for the cost-effective long-term conservation and management of germplasm collections and facilitate access to useful Musa genetic resources in improvement programmes and by other users. Enhance the value of Musa genetic resources for breeding, through effective collaborative characterization and pre-breeding efforts. Raise awareness with key partners on the importance of Musa genetic resources conservation, documentation and sharing the benefits arising from their use. Set priorities for research and use of Musa genetic resources, ensuring critical links with the four regional banana networks. Members of MusaNet belong to one or more of the five thematic research groups focused on the following subjects: Diversity, Evaluation and Information; each of these thematic groups has elected a Chair and Co-chair to represent the group at monthly Expert Committee meetings and has developed objectives and a workplan for the next 10 years. Present in the Expert Committee are representatives of the four regional banana networks - BAPNET, BARNESA, Innovate Plantain and MUSALAC, which geographically cover all the banana producing countries.

A representative from the information platform ProMusa is present at the meetings. Part of the Diversity Thematic Group, the Taxonomic Advisory Group comprises 12 experts that work together on particular projects concerning banana taxonomy, such as developing morphological field descriptors and verifying the genetic integrity of banana germplasm. Membership to MusaNet is based on individuals, not institutes, is solicited by thematic group Chairs and Co-chairs. Members are active in banana genetic resources-related research with a commitment to fruitful collaboration and knowledge exchange. There are more than 60 banana ex situ collections worldwide located in banana producing countries; the majority of the collections are supported by national funding to conserve banana diversity and conduct related research. Detailed information of the collections can be found on the MusaNet website. Projects in MusaNet are developed among the five thematic groups; some recent activities carried out by MusaNet members are: The publication of the revised Global Strategy for the Conservation and Use of Musa Genetic Resources.

The revision of the Technical Guidelines for the Safe Movement of Musa Germplasm Regional workshops on Musa characterization and documentation - held in Cameroon, Uganda and Costa Rica. Creation of the Taxonomic Reference Collection - a reference set of accessions representing the spectrum of Musa diversity Collecting missions carried out with local partners in Indonesia and Papua New Guinea Development of electronic tools used for field characterization: MusaTab and MusaID Building plant phytosanitary capacity in national collections through a Virus Ring Test Banana Genomics workshop organised annually at the Plant and Animal Genome Conference in San Diego, USA. Ongoing development of standardized protocols for the evaluation of Black leaf streak, Fusarium wilt and Drought tolerance; the Musa Germplasm Information System is linked with the Information Thematic Group activities. It contains accession-level information of germplasm held in many Musa collections. MusaNet website Bioversity International Promusa Musa Germplasm Information System