American Signals

Radio signals

2009-12-09T20:20:00.001-08:00

At Signal Hill on December 12, 1901, Guglielmo Marconi and his assistant, George Kemp, confirmed the reception of the first transatlantic radio signals. With a telephone receiver and a wire antenna kept aloft by a kite, they heard Morse code for the letter "S" transmitted from Poldhu, Cornwall. Their experiments showed that radio signals extended far beyond the horizon, giving radio a new global dimension for communication in the twentieth century.

On 12 December 1901, Guglielmo Marconi and his assistant, George Kemp, heard the faint clicks of Morse code for the letter "s" transmitted without wires across the Atlantic Ocean. This achievement, the first reception of transatlantic radio signals, led to considerable advances in both science and technology. It demonstrated that radio transmission was not bounded by the horizon, thus prompting Arthur Kennelly and Oliver Heaviside to suggest, shortly thereafter, the existence of a layer of ionized air in the upper atmosphere (the Kennelly-Heaviside layer, now called the ionosphere). Marconi's experiment also gave the new technology of "wireless telegraphy" a global dimension that eventually made radio one of the major forms of communication in the twentieth century.

In 1901, Marconi built a powerful wireless station at Poldhu, Cornwall, (corresponding IEEE Milestone) in preparation for a transatlantic test. The spark-gap transmitter fed a mammoth antenna array -- four hundred wires suspended from 20 masts, each 200 feet tall, placed in a circle. A similar station was set up on the American side of the Atlantic at South Wellfleet, Cape Cod.

Then a series of disasters struck. On 17 September a ferocious gale hit the Poldhu station, destroying the elaborate antenna system. A temporary one was put in its place a week later, but tests showed that it was too inefficient to reach the Cape Cod station. Consequently, before leaving England for North America, Marconi decided to set up his equipment at St. John's, Newfoundland, which was much closer to Poldhu. The decision proved academic in any case, because on 26 November, the day before Marconi's scheduled departure, the Cape Cod antenna blew down in a hurricane.

Landing at St. John's on 6 December, Marconi and his assistants set up their experimental apparatus on a table in the Signal Hill barracks near the harbor. Meanwhile, an improved antenna: had been installed at the Poldhu station, whose operators had instructions to send Morse code for the letter "s" from 3 to 7 pm (GMT) starting on 11 December. Marconi tested the winds on the 10th by sending aloft a kite trailing a wire antenna, but the kite broke loose. At the prearranged time on the 11th, Marconi and his assistants sent up a balloon, but heard nothing from their receiver. They next dispensed with the tuned receiver and tried a more sensitive detector, but the balloon broke loose. On the 12th, a strong gale still blew and carried away the first kite they sent up. The second kite, which trailed 500 feet of antenna wire, stayed up long enough for Marconi and Kemp to hear the transatlantic signals through a telephone earpiece connected to the receiver. Marconi's diary for that date has the simple entry, "Sigs. at 12:30, 1:10 and 2:20. 11 more signals were confirmed on the next day, Friday the 13th, but none on Saturday. On Monday the 16th, Marconi released the news to the press and then began packing for a new location because the Anglo-American Telegraph Company threatened legal action for violating its communication monopoly in Newfoundland.

Marconi's announcement met with enthusiastic acclaim, but also with some skepticism. After all, the only witness was George Kemp, hardly an impartial observer, and the signals were too weak to operate an automatic recorder. Two months later, though, Marconi received transatlantic signals of sufficient strength from Poldhu to operate a Morse inker in the presence of witnesses. (Although later knowledge of radio-wave propagation indicates that the Signal Hill reception occurred under inopportune conditions, recent historians have suggested that Marconi picked up a high-frequency harmonic on his un-tuned receiver.) In January 1902, between the time of the Signal Hill reception and the later verification, the American Institute of Electrical Engineers held their annual dinner meeting in honor of Marconi. In attendance were such electrical engineering notables as Alexander Graham Bell, Charles Proteus Steinmetz, and Michael Pupin. Thomas Edison, who sent his regrets, called Marconi "the young man who had the monumental audacity to attempt, and succeed in, jumping an electrical wave clear across the Atlantic Ocean."

American satellite tv

2009-12-09T20:12:00.000-08:00

Satellite television is television delivered by the means of communications satellite and received by a satellite dish and set-top box. In many areas of the world it provides a wide range of channels and services, often to areas that are not serviced by terrestrial or cable providers.

American digital

2009-12-09T20:11:00.000-08:00

Overview
Are you doing nightly backups? Is it easy for you to share files across your business? You have more pressing concerns than how to backup and share your data.

The HP StorageWorks X500 Data Vault series provides a simple and cost effective solution for a small business to store, secure and share data for under $1000. Based on Microsoft Windows Home Server, it provides a user friendly interface with easy installation and management. The HP X500 provides you with automated backup for up to 10 PC clients and Mac's on the network while providing additional background features like folder duplication and data deduplication. The X500 offers both local and remote file sharing via a custom URL which is accessible from any web browser. The HP X500 comes with two or three empty bays (depending on the model) for internal storage expansion and also offers external USB and eSATA ports for additional external expansion. Store it, secure it, share it.

Simple Data Protection

Features

Ideal for Small Businesses
• For businesses with 10 or less PC and Mac clients, The HP StorageWorks X500 Data Vault provides full system protection. The HP Data Vault automatically backs up each client every day without you having to manage the process.

Consolidation is simple
• Once installed, your HP X500 will allow you to consolidate your data and PC or Mac client backups onto one device. This consolidation makes your storage process efficient and easy to manage.

Automated daily backups and easy restore
• You get peace of mind with simple automated daily backups. Install the client software on any PC on your network and the HP X500 Data Vault does the rest. Daily backups are reviewable as individual files. You can open any backup and restore a single file or multiple files.

Better business security
• Protect your business by protecting your most important asset: your data.

Local and remote file sharing
• Share files on the local network via the HP StorageWorks X500 Data Vault. Create shared folders based on your business needs. Access your Data Vault from any internet connected computer via a custom web address that you create. Use the remote computer like your own PC.

Personalized Web Address
• Create a custom web address of your choosing. Access your HP X500 Data Vault through your custom web address from any internet connected computer. Web addresses are registered through HP's partner TZO.com. Your web address is free for the first year with a low nominal cost for each additional year.

Reduced Ongoing Costs
• Most online services charge a monthly fee to access your files. With the X500 and a custom domain from TZO.com accessing your files is free for the first year and costs a nominal fee each year after.

Better collaboration
• The local and remote file sharing capabilities on the HP X500 Data Vault provide for more efficient business collaboration.

Duplicate critical files
• The HP StorageWorks X500 Data Vault lets you choose which file folders are the most important. With the ease of a mouse click, you can tell the X500 to duplicate that folder to a second hard disk drive. If a hard disk drive was to fail, your data will still be safe on the second hard disk drive.

User access control and authentication
• Access to shared file folders can be easily managed through a mouse click. Set Read/Write, Read Only or No Access privileges for each user, to each shared folder. Users login and authenticate, with a strong password, to access the HP X500 Data Vault shared folders or PC applications.

Built-in Anti-Virus protection
• The X500 comes with a version of McAfee Anti-Virus software which you can choose to install. You can also use your existing anti-virus software to easily scan the Data Vault.

Easily Add More Storage
• Easy to expand to 6 TB internally and up to 13.5 TB with external storage options. The HP StorageWorks X500 Data Vault supports hot swapping of hard disk drives which means that to add capacity you do not need to power down the device. The X500 grows as your business grows.

External Capacity Upgrades
• Four (4) USB ports and one (1) eSATA port are available to add additional storage.

Signals audio

2009-12-09T20:10:00.001-08:00

Audio signal processing, sometimes referred to as audio processing, is the intentional alteration of auditory signals, or sound. As audio signals may be electronically represented in either digital or analog format, signal processing may occur in either domain. Analog processors operate directly on the electrical signal, while digital processors operate mathematically on the binary representation of that signal.

Human hearing extends from approximately 20 Hz to 20 kHz, determined both by physiology of the human hearing system and by human psychology. These properties are analysed within the field of psychoacoustics.

Digital Signal Processing

2009-12-09T20:09:00.004-08:00

This session has been organized by the DSP research network of ISTEC-R&D with the objective to present applications and results of research projects in areas related to Digital Signal Processing.

The purpose of this session is to share and exchange experiences from research projects and applications that use Digital Signal Processing techniques and methods in a variety of fields, as well as to showcase applications developed for different types of industries, and to enhance the instructional processes for undergraduate and graduate students.

Participants:
Teachers, researchers, graduate and undergraduate students, industry professionals engineers with related research and development of applications in the area.

Language:
English and Spanish

Important Deadlines:
Paper Submission: Online until August 17, 2009
Notification of Acceptance: September 1st, 2009
Early Registration: Until midnight October 5th, 2009 (MST)
Event: October 27 and 28, 2009

Related Events:
Embedded Systems Design using FPGAs Workshop

Registration:
To participate in this session interested parties must register for the Ibero-American Conference on Trends in Engineering Education and Collaboration.

American digital signals

2009-12-09T20:09:00.003-08:00

An equalization technique for the compensation of degradation caused by multipath Rayleigh fading channels to the transmission of digitally modulated signals such as pi DIVIDED 4. Differential Quadrature Phase Shift Keying (DQPSK) modulated signals. The technique is applicable to both linear and nonlinear transversal equalizers. Based on the Method of Projection onto Convex Sets (POCS), the technique is realized in an iterative form. The convergence speed of equalization depends on the magnitude of a look-back parameter, and is comparable to the speed of recursive least square based equalizers. The computational complexity of the technique also is variable and is adaptable to the convergence speed requirements. For achieving convergence speeds as recursive least square techniques, the computational load required of the presented equalization is of the order of the load required of the recursive least square techniques, but its program implementation is exceedingly simpler. At the same time the code size, memory and power consumption requirements are lower.

American digital signals

2009-12-09T20:09:00.001-08:00

American Analog Set

2009-12-09T20:08:00.001-08:00

Since the middle of the 1990s, a tasteful quintet from the Lone Star State called The American Analog Set has been shaping perfect pieces of graceful, economical indie pop. Like the late lamented Bedhead, which also came out of the Dallas/Fort Worth area, this group explores subtle quiet moods, but steers clear of Bedhead's occasional noisiness and dark brooding jags, tending instead toward the warm, mellow, bliss of a late summer's afternoon. Nothing about their songs feels indulgent, as so often seems to be the case with groups working the slow and quiet indie pop tip, and that proves very refreshing. The American Analog Set keeps the tempos moderate and steady, skating lightly across the surface of your consciousness with a winning mixture of soft, carefully considered vocals, warm dreamy guitars, a languid rhythm section, and occasional gentle ripples of organ. The combination may remind you of some of your favorite old Yo La Tengo guitar pop songs.

Since forming from the ashes of a group called Electric Company back in 1994, the American Analog Set has been recording records at a fairly steady rate, issuing three on Emperor Jones Records before moving on to Tiger Style, which put out their beautifully low-key album Know By Heart in 2001. They've also put out a rarities collection on Emperor Jones, Through the 1990s: Singles and Unreleased, and a 2002 remix EP called Updates with point-and-click from folks like Her Space Holiday and Styrofoam.

American analog

2009-12-09T20:05:00.000-08:00

The American Analog Set, also known as The AmAnSet, is an indie rock band from Austin, Texas, USA. The group is led by singer and guitarist Andrew Kenny. Additional members include or have included Lee Gillespie, Mark Smith, Craig McCaffrey, Tom Hoff, Lisa Roschmann and Sean Ripple. Their name derives from their preference for analog rather than digital recording media. Formed in 1995, the group has released six full-length albums the latest one being Set Free, which was released on September 20, 2005 in North America.

In October 2005, rumours began spreading across the internet that the group was on the verge of disbanding. The band quickly refuted such rumours, but added that they may not tour again due to their obligations with other projects.