Sample records for existing navigation lock

  1. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and... § 207.185 Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation...

  2. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and... § 207.185 Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation...

  3. 75 FR 76943 - Regulated Navigation Area; Hudson River South of the Troy Locks, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ...-AA11 Regulated Navigation Area; Hudson River South of the Troy Locks, NY AGENCY: Coast Guard, DHS... Navigation Area (RNA) on the navigable waters of the Hudson River in New York, south of the Troy Locks. This... within the waters of the Hudson River south of the Troy Locks when ice is a threat to navigation. DATES...

  4. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation... REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  5. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation... REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  6. 33 CFR 207.175a - Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration, and navigation. 207.175a Section 207.175a... REGULATIONS § 207.175a Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration...

  7. 33 CFR 207.175a - Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration, and navigation. 207.175a Section 207.175a... REGULATIONS § 207.175a Carlson's Landing Dam navigation lock, Withlacoochee River, Fla.; use, administration...

  8. 75 FR 8486 - Regulated Navigation Area; Hudson River south of the Troy Locks, New York

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ...-AA11 Regulated Navigation Area; Hudson River south of the Troy Locks, New York AGENCY: Coast Guard, DHS... area on the navigable waters of the Hudson River south of the Troy Locks. This regulated navigation... Hudson River south of the Troy locks when ice conditions are 8 inches or greater unless authorized by the...

  9. 76 FR 8654 - Regulated Navigation Area; Hudson River South of the Troy Locks, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ...-AA11 Regulated Navigation Area; Hudson River South of the Troy Locks, NY AGENCY: Coast Guard, DHS... navigable waters of the Hudson River in New York, south of the Troy Locks. This action is necessary to... Hudson River south of the Troy Locks when ice is a threat to navigation. DATES: This rule is effective in...

  10. 33 CFR 162.175 - Black Rock Canal and Lock at Buffalo, New York.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Black Rock Canal and Lock at Buffalo, New York. 162.175 Section 162.175 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Black Rock Canal and Lock at Buffalo, New York. In the Black Rock Canal and Lock, no vessel may exceed 6...

  11. 33 CFR 162.175 - Black Rock Canal and Lock at Buffalo, New York.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Black Rock Canal and Lock at Buffalo, New York. 162.175 Section 162.175 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Black Rock Canal and Lock at Buffalo, New York. In the Black Rock Canal and Lock, no vessel may exceed 6...

  12. 33 CFR 162.175 - Black Rock Canal and Lock at Buffalo, New York.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Black Rock Canal and Lock at Buffalo, New York. 162.175 Section 162.175 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Black Rock Canal and Lock at Buffalo, New York. In the Black Rock Canal and Lock, no vessel may exceed 6...

  13. 33 CFR 162.175 - Black Rock Canal and Lock at Buffalo, New York.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Black Rock Canal and Lock at Buffalo, New York. 162.175 Section 162.175 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Black Rock Canal and Lock at Buffalo, New York. In the Black Rock Canal and Lock, no vessel may exceed 6...

  14. 33 CFR 162.175 - Black Rock Canal and Lock at Buffalo, New York.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Black Rock Canal and Lock at Buffalo, New York. 162.175 Section 162.175 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Black Rock Canal and Lock at Buffalo, New York. In the Black Rock Canal and Lock, no vessel may exceed 6...

  15. 5 CFR 532.269 - Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam employees.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Engineers, U.S. Army navigation lock and dam employees. 532.269 Section 532.269 Administrative Personnel... Determinations § 532.269 Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam... and dam equipment or who repair and maintain navigation lock and dam operating machinery and equipment...

  16. 33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation lock...

  17. 33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation lock...

  18. 33 CFR 207.170a - Eugene J. Burrell Navigation Lock in Haines Creek near Lisbon, Fla.; use, administration, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Eugene J. Burrell Navigation Lock in Haines Creek near Lisbon, Fla.; use, administration, and navigation. 207.170a Section 207.170a... REGULATIONS § 207.170a Eugene J. Burrell Navigation Lock in Haines Creek near Lisbon, Fla.; use...

  19. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Black Rock Canal and Lock at... Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation. (a) The term “canal” when used in this section will mean all of the Black Rock Waterway, including Black Rock Lock, and all...

  20. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Black Rock Canal and Lock at... Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation. (a) The term “canal” when used in this section will mean all of the Black Rock Waterway, including Black Rock Lock, and all...

  1. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Black Rock Canal and Lock at... Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation. (a) The term “canal” when used in this section will mean all of the Black Rock Waterway, including Black Rock Lock, and all...

  2. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Black Rock Canal and Lock at... Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation. (a) The term “canal” when used in this section will mean all of the Black Rock Waterway, including Black Rock Lock, and all...

  3. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hudson River Lock at Troy, N.Y..., DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.50 Hudson River Lock at Troy, N.Y.; navigation. (a...) [Reserved] (n) Trespass on U.S. property. Trespass on U.S. property, or willful injury to the banks, masonry...

  4. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false St. Marys Falls Canal and Locks... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.441 St. Marys Falls Canal and Locks... the conduct of crew and passengers while transiting St. Marys Falls Canal and Locks and for strict...

  5. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., administration, and navigation of canal and locks at Willamette Falls, Oreg. 207.680 Section 207.680 Navigation... Willamette Falls, Oreg. (a) Administration—(1) Administrative jurisdiction. The canal and locks and all... VHF-FM radio on channel 14, at WUJ 363, Willamette Falls Locks or by telephone or otherwise notifying...

  6. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false St. Marys Falls Canal and Locks... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.441 St. Marys Falls Canal and Locks... the conduct of crew and passengers while transiting St. Marys Falls Canal and Locks and for strict...

  7. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., administration, and navigation of canal and locks at Willamette Falls, Oreg. 207.680 Section 207.680 Navigation... Willamette Falls, Oreg. (a) Administration—(1) Administrative jurisdiction. The canal and locks and all... VHF-FM radio on channel 14, at WUJ 363, Willamette Falls Locks or by telephone or otherwise notifying...

  8. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false St. Marys Falls Canal and Locks... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.441 St. Marys Falls Canal and Locks... the conduct of crew and passengers while transiting St. Marys Falls Canal and Locks and for strict...

  9. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false St. Marys Falls Canal and Locks... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.441 St. Marys Falls Canal and Locks... the conduct of crew and passengers while transiting St. Marys Falls Canal and Locks and for strict...

  10. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., administration, and navigation of canal and locks at Willamette Falls, Oreg. 207.680 Section 207.680 Navigation... Willamette Falls, Oreg. (a) Administration—(1) Administrative jurisdiction. The canal and locks and all... VHF-FM radio on channel 14, at WUJ 363, Willamette Falls Locks or by telephone or otherwise notifying...

  11. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false St. Marys Falls Canal and Locks... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.441 St. Marys Falls Canal and Locks... the conduct of crew and passengers while transiting St. Marys Falls Canal and Locks and for strict...

  12. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false St. Marys Falls Canal and Locks.... Marys Falls Canal and Locks, Mich.; use, administration, and navigation. (a) The use, administration... by radiotelephone to the Corps of Engineers Chief Lockmaster at St. Marys Falls Canal dispatch tower...

  13. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false St. Marys Falls Canal and Locks.... Marys Falls Canal and Locks, Mich.; use, administration, and navigation. (a) The use, administration... by radiotelephone to the Corps of Engineers Chief Lockmaster at St. Marys Falls Canal dispatch tower...

  14. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false St. Marys Falls Canal and Locks.... Marys Falls Canal and Locks, Mich.; use, administration, and navigation. (a) The use, administration... by radiotelephone to the Corps of Engineers Chief Lockmaster at St. Marys Falls Canal dispatch tower...

  15. 15. DETAIL INTERIOR VIEW OF CONTROL HOUSE FOR NAVIGATION LOCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. DETAIL INTERIOR VIEW OF CONTROL HOUSE FOR NAVIGATION LOCK #1. Photograph Nos. OR-11-D-16 through OR-11-D-27 are photocopies of photographs. Original historic photographs are located at the Bonneville Powerhouse, Bonneville, Oregon. - Bonneville Project, Navigation Lock No. 1, Oregon shore of Columbia River near first Powerhouse, Bonneville, Multnomah County, OR

  16. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Sacramento Deep Water Ship... REGULATIONS § 207.640 Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and navigation. (a) Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use...

  17. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Sacramento Deep Water Ship... REGULATIONS § 207.640 Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and navigation. (a) Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use...

  18. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Sacramento Deep Water Ship... REGULATIONS § 207.640 Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and navigation. (a) Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use...

  19. Evaluation of fish sampling using rotenone in a navigation lock

    USGS Publications Warehouse

    Margraf, F.J.; Knight, C.T.

    2002-01-01

    Annual sampling in locks with rotenone has been a principal means of assessing fish populations in the commercially navigable portions of the Ohio River. Despite extensive use, sampling in locks with rotenone and interpretation of the data obtained have not been adequately evaluated. The purpose of our study was to determine the degree of inter- and intraseasonal variation in lock samples, estimate correction factors (CFs) for fish recovery rates, and compare lock samples to other fish collections from the navigational pools above and below the lock. Lock samples from all seasons had a greater proportion of pelagic and demersal fish than samples from the navigational pools, which contained greater proportions of littoral species. CF for non-recovery of fish were determined. Spring and summer lock collections yielded several more species and estimates of overall fish biomass were an order of magnitude higher than fall collections. Within season variation between lock samples was relatively low; however, variation in lock samples among seasons was high, equivalent to that seen among the annual samples from the 1980s. Thus, single-season sampling may not be adequate, and fall may be the least preferred season.

  20. 33 CFR 207.320 - Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Mississippi River, Twin City... § 207.320 Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level. In... the Twin City Locks and Dam, Minneapolis, in the interest of navigation, and supersedes rules and...

  1. 33 CFR 207.320 - Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Mississippi River, Twin City... § 207.320 Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level. In... the Twin City Locks and Dam, Minneapolis, in the interest of navigation, and supersedes rules and...

  2. 33 CFR 207.320 - Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Mississippi River, Twin City... § 207.320 Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level. In... the Twin City Locks and Dam, Minneapolis, in the interest of navigation, and supersedes rules and...

  3. 33 CFR 165.930 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Safety Zone, Brandon Road Lock... Guard District § 165.930 Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION...

  4. 33 CFR 207.320 - Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Mississippi River, Twin City... § 207.320 Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level. In... the Twin City Locks and Dam, Minneapolis, in the interest of navigation, and supersedes rules and...

  5. 33 CFR 207.320 - Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Mississippi River, Twin City... § 207.320 Mississippi River, Twin City Locks and Dam, St. Paul and Minneapolis, Minn.; pool level. In... the Twin City Locks and Dam, Minneapolis, in the interest of navigation, and supersedes rules and...

  6. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... through the locks. The controlling water depth over the intermediate miter sills throughout the locks is 6.5 feet. However, the depth on the sill of the upstream gate at low water is 7.5 feet and over the...

  7. Electromagnetic navigation reduces surgical time and radiation exposure for proximal interlocking in retrograde femoral nailing.

    PubMed

    Somerson, Jeremy S; Rowley, David; Kennedy, Chad; Buttacavoli, Frank; Agarwal, Animesh

    2014-07-01

    To compare the time required for proximal locking screw placement between a standard freehand technique and the navigated technique, and to quantify the reduction in ionizing radiation exposure. A fresh frozen cadaver model was used for 48 proximal interlocking screw procedures. Each procedure consisted of insertion of 2 anteroposterior locking screws. Standard fluoroscopic technique was used for 24 procedures, and an electromagnetic navigation system was used for the remaining 24 procedures. Procedure duration was recorded using an electronic timer and radiation doses were documented. Mean total insertion time for both proximal interlocking screws was 405 ± 165.7 seconds with the freehand technique and 311 ± 78.3 seconds in the navigation group (P = 0.002). All procedures resulted in successful locking screw placement. Mean ionizing radiation exposure time for proximal locking was 29.5 ± 12.8 seconds. Proximal locking screw insertion using the navigation technique evaluated in this work was significantly faster than the standard fluoroscopic method. The navigated technique is effective and has the potential to prevent ionizing radiation exposure.

  8. 33 CFR 207.425 - Calumet River, Ill.; Thomas J. O'Brien Lock and Controlling Works and the use, administration and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Calumet River, Ill.; Thomas J. O... DEFENSE NAVIGATION REGULATIONS § 207.425 Calumet River, Ill.; Thomas J. O'Brien Lock and Controlling Works... paragraph (a)(1) of this section. (b) Lock—(1) Operation. The Thomas J. O'Brien Lock and Dam is part of the...

  9. 33 CFR 207.187 - Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Gulf Intracoastal Waterway on the Colorado River. The legend states “DO NOT PROCEED BEYOND THIS POINT... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Gulf Intracoastal Waterway, Tex... Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations. (a) Application...

  10. 33 CFR 207.187 - Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Gulf Intracoastal Waterway on the Colorado River. The legend states “DO NOT PROCEED BEYOND THIS POINT... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Gulf Intracoastal Waterway, Tex... Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations. (a) Application...

  11. Montgomery Point Lock and Dam, White River, Arkansas

    DTIC Science & Technology

    2016-01-01

    ER D C/ CH L TR -1 6- 1 Monitoring Completed Navigation Projects (MCNP) Program Montgomery Point Lock and Dam, White River, Arkansas Co...Navigation Projects (MCNP) Program ERDC/CHL TR-16-1 January 2016 Montgomery Point Lock and Dam, White River, Arkansas Allen Hammack, Michael Winkler, and...20314-1000 Under MCNP Work Unit: Montgomery Point Lock and Dam, White River, Arkansas ERDC/CHL TR-16-1 ii Abstract Montgomery Point Lock and

  12. National Waterways Study. Waterway Science and Technology.

    DTIC Science & Technology

    1981-08-01

    Revetments 278 VII-A Split Hull Type Trailing Suction Hopper Dredge 304 VII-B Drag Heads 306 VII-C Overflow Systems 307 VII-D Trailing Suction Hopper... head reversals are possible. Poor approach conditions currently exist at some locks which could have been mitigated if modern, improved design...of ti,.c that a navigable pass section can be used. Navigation dams must be designed to pass high flows and floods with minor swell head and without in

  13. 33 CFR 165.T09-0166 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone, Brandon Road Lock... Areas Ninth Coast Guard District § 165.T09-0166 Safety Zone, Brandon Road Lock and Dam to Lake Michigan.... waters of the Des Plaines River located between mile marker 286.0 (Brandon Road Lock and Dam) and mile...

  14. Next generation distal locking for intramedullary nails using an electromagnetic X-ray-radiation-free real-time navigation system.

    PubMed

    Hoffmann, Michael; Schröder, Malte; Lehmann, Wolfgang; Kammal, Michael; Rueger, Johannes Maria; Herrman Ruecker, Andreas

    2012-07-01

    Distal locking marks one challenging step during intramedullary nailing that can lead to an increased irradiation and prolonged operation times. The aim of this study was to evaluate the reliability and efficacy of an X-ray-radiation-free real-time navigation system for distal locking procedures. A prospective randomized cadaver study with 50 standard free-hand fluoroscopic-guided and 50 electromagnetic-guided distal locking procedures was performed. All procedures were timed using a stopwatch. Intraoperative fluoroscopy exposure time and absorbed radiation dose (mGy) readings were documented. All tibial nails were locked with two mediolateral and one anteroposterior screw. Successful distal locking was accomplished once correct placement of all three screws was confirmed. Successful distal locking was achieved in 98 cases. No complications were encountered using the electromagnetic navigation system. Eight complications arose during free-hand fluoroscopic distal locking. Undetected secondary drill slippage on the ipsilateral cortex accounted for most problems followed by undetected intradrilling misdirection causing a fissural fracture of the contralateral cortex while screw insertion in one case. Compared with the free-hand fluoroscopic technique, electromagnetically navigated distal locking provides a median time benefit of 244 seconds without using ionizing radiation. Compared with the standard free-hand fluoroscopic technique, the electromagnetic guidance system used in this study showed high reliability and was associated with less complications, took significantly less time, and used no radiation exposure for distal locking procedures. Therapeutic study, level II.

  15. 33 CFR 165.T08-0434 - Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile Marker 108.5 West of Harvey Lock Gulf... § 165.T08-0434 Safety Zone; Mile Marker 98.5 West of Harvey Lock Gulf Intracoastal Waterway to Mile...

  16. Virtual wayfinding using simulated prosthetic vision in gaze-locked viewing.

    PubMed

    Wang, Lin; Yang, Liancheng; Dagnelie, Gislin

    2008-11-01

    To assess virtual maze navigation performance with simulated prosthetic vision in gaze-locked viewing, under the conditions of varying luminance contrast, background noise, and phosphene dropout. Four normally sighted subjects performed virtual maze navigation using simulated prosthetic vision in gaze-locked viewing, under five conditions of luminance contrast, background noise, and phosphene dropout. Navigation performance was measured as the time required to traverse a 10-room maze using a game controller, and the number of errors made during the trip. Navigation performance time (1) became stable after 6 to 10 trials, (2) remained similar on average at luminance contrast of 68% and 16% but had greater variation at 16%, (3) was not significantly affected by background noise, and (4) increased by 40% when 30% of phosphenes were removed. Navigation performance time and number of errors were significantly and positively correlated. Assuming that the simulated gaze-locked viewing conditions are extended to implant wearers, such prosthetic vision can be helpful for wayfinding in simple mobility tasks, though phosphene dropout may interfere with performance.

  17. 33 CFR 207.187 - Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Definitions. The term current means the velocity of flow of water in the river. It is expressed in statute... provided in paragraph (d)(4) of § 207.180. (d) Navigation of the Colorado River Channel—(1) Traffic signals... the East Lock of the Colorado River Locks to direct the interchange of traffic in the Colorado River...

  18. 33 CFR 207.425 - Calumet River, Ill.; Thomas J. O'Brien Lock and Controlling Works and the use, administration and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Calumet River, Ill.; Thomas J. O... DEFENSE NAVIGATION REGULATIONS § 207.425 Calumet River, Ill.; Thomas J. O'Brien Lock and Controlling Works... Illinois Waterway, or when the lake level is below minus 2 feet, Chicago City Datum. (2) The elevation to...

  19. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... and the bottom of the lock chamber are −13.0 feet elevation, CofE datum, and usually provides a depth of water ranging from 14.0 feet at LLW to 19.4 feet at HHW, with greater depths during large floods...

  20. 27. photographer unknown 10 July 1938 SHIP LOCK DEDICATION CEREMONIES. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. photographer unknown 10 July 1938 SHIP LOCK DEDICATION CEREMONIES. - Bonneville Project, Navigation Lock No. 1, Oregon shore of Columbia River near first Powerhouse, Bonneville, Multnomah County, OR

  1. Navigation Lock and Dam Inspection and Emergency Repairs Workshop Summary

    DTIC Science & Technology

    2006-09-01

    Inspection and Emergency Repairs Workshop Summary John E. Hite, Jr., James E. Clausner, and Dinah N. McComas, editors Coastal and Hydraulics Laboratory...Engineer Research and Development Center (ERDC) Coastal and Hydraulics Laboratory hosted a “Navigation Lock and Dam Inspection and Emergency Repairs...applications ..............................................................................12 Current inspection policies for hydraulic steel structures

  2. Comparison of free-hand fluoroscopic guidance and electromagnetic navigation in distal locking of femoral intramedullary nails

    PubMed Central

    Han, Bing; Shi, Zhigang; Fu, Yu; Ye, Yong; Jing, Juehua; Li, Jun

    2017-01-01

    Abstract Background: Although the method has been used widely, one of the greatest challenges for intramedullary nailing is to position the distal locking screw. A new technology, the electromagnetic navigation system, is a radiation-free way to locate the position of the drill bit and provide 3-dimensional real-time feedback of location and orientation of the drill bit relative to the locking holes. The purpose of our study was to evaluate the reliability and efficiency of the free-hand technique compared to the new electromagnetic navigation system. Methods: Fifty-four patients with femoral fracture who needed treatment with intramedullary nails were divided into 2 groups. One group including 26 patients underwent distal locking using the standard free-hand method, whereas the electromagnetic navigation system was used with the other 29 patients. Intraoperative fluoroscopy exposure times, screw insertion times, and healing times were recorded; these parameters were used for comparison between the 2 groups. Results: There were 17 males and 9 females who had femoral intramedullary nails using the free-hand technique, whereas 21 males and 8 females received intramedullary nails using the electromagnetic navigation system. The mean time of distal locking was 19.5 ± 6.0 minutes in the free-hand (FH) group, whereas the time was 6.1 ± 1.4 minutes in the electromagnetic (ET) group. The exposure time for the FH group was 26.8 ± 13.3 seconds and 2.2 ± 1.1 seconds for the ET group. Healing time proved to be comparable in the FH and ET groups (16.4 ± 3.7 weeks vs 15.1 ± 2.8 weeks). Conclusion: Under the premise of achieving the same effect, the electromagnetic navigation system has the advantage of less distal locking time and less radiation dose. PMID:28723755

  3. Comparison of free-hand fluoroscopic guidance and electromagnetic navigation in distal locking of femoral intramedullary nails.

    PubMed

    Han, Bing; Shi, Zhigang; Fu, Yu; Ye, Yong; Jing, Juehua; Li, Jun

    2017-07-01

    Although the method has been used widely, one of the greatest challenges for intramedullary nailing is to position the distal locking screw. A new technology, the electromagnetic navigation system, is a radiation-free way to locate the position of the drill bit and provide 3-dimensional real-time feedback of location and orientation of the drill bit relative to the locking holes. The purpose of our study was to evaluate the reliability and efficiency of the free-hand technique compared to the new electromagnetic navigation system. Fifty-four patients with femoral fracture who needed treatment with intramedullary nails were divided into 2 groups. One group including 26 patients underwent distal locking using the standard free-hand method, whereas the electromagnetic navigation system was used with the other 29 patients. Intraoperative fluoroscopy exposure times, screw insertion times, and healing times were recorded; these parameters were used for comparison between the 2 groups. There were 17 males and 9 females who had femoral intramedullary nails using the free-hand technique, whereas 21 males and 8 females received intramedullary nails using the electromagnetic navigation system. The mean time of distal locking was 19.5 ± 6.0 minutes in the free-hand (FH) group, whereas the time was 6.1 ± 1.4 minutes in the electromagnetic (ET) group. The exposure time for the FH group was 26.8 ± 13.3 seconds and 2.2 ± 1.1 seconds for the ET group. Healing time proved to be comparable in the FH and ET groups (16.4 ± 3.7 weeks vs 15.1 ± 2.8 weeks). Under the premise of achieving the same effect, the electromagnetic navigation system has the advantage of less distal locking time and less radiation dose.

  4. Environmental engineering of navigation infrastructure: a survey of existing practices, challenges, and potential opportunities.

    PubMed

    Fredette, Thomas J; Foran, Christy M; Brasfield, Sandra M; Suedel, Burton C

    2012-01-01

    Navigation infrastructure such as channels, jetties, river training structures, and lock-and-dam facilities are primary components of a safe and efficient water transportation system. Planning for such infrastructure has until recently involved efforts to minimize impacts on the environment through a standardized environmental assessment process. More recently, consistent with environmental sustainability concepts, planners have begun to consider how such projects can also be constructed with environmental enhancements. This study examined the existing institutional conditions within the US Army Corps of Engineers and cooperating federal agencies relative to incorporating environmental enhancements into navigation infrastructure projects. The study sought to (1) investigate institutional attitudes towards the environmental enhancement of navigation infrastructure (EENI) concept, (2) identify potential impediments to implementation and solutions to such impediments, (3) identify existing navigation projects designed with the express intent of enhancing environmental benefit in addition to the primary project purpose, (4) identify innovative ideas for increasing environmental benefits for navigation projects, (5) identify needs for additional technical information or research, and (6) identify laws, regulations, and policies that both support and hinder such design features. The principal investigation tool was an Internet-based survey with 53 questions. The survey captured a wide range of perspectives on the EENI concept including ideas, concerns, research needs, and relevant laws and policies. Study recommendations included further promotion of the concept of EENI to planners and designers, documentation of existing projects, initiation of pilot studies on some of the innovative ideas provided through the survey, and development of national goals and interagency agreements to facilitate implementation. Copyright © 2011 SETAC.

  5. 5 CFR 532.269 - Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam employees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam employees. 532.269 Section 532.269 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate...

  6. Limitations of navigation through Nubaria canal, Egypt.

    PubMed

    Samuel, Magdy G

    2014-03-01

    Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

  7. 33 CFR 207.476 - The Inland Route-lock in Crooked River, Alanson, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... management of the lock, and of the area set aside as the lock area, including the lock approach channels. He..., both to the employees of the Government and to any and every person within the limits of the lock area... object in the lock or approaches except by or under the direction of the lockmaster or his assistants. (c...

  8. 33 CFR 207.476 - The Inland Route-lock in Crooked River, Alanson, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... management of the lock, and of the area set aside as the lock area, including the lock approach channels. He..., both to the employees of the Government and to any and every person within the limits of the lock area... object in the lock or approaches except by or under the direction of the lockmaster or his assistants. (c...

  9. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Harbor Navigation Canal, New Orleans. (a) The draws of the SR 46 (St. Claude Avenue) bridge, mile 0.5 (GIWW mile 6.2 East of Harvey Lock), the SR 39 (Judge Seeber/Claiborne Avenue) bridge, mile 0.9 (GIWW mile 6.7 East of Harvey Lock), and the Florida Avenue bridge, mile 1.7 (GIWW mile 7.5 East of Harvey...

  10. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Harbor Navigation Canal, New Orleans. (a) The draws of the SR 46 (St. Claude Avenue) bridge, mile 0.5 (GIWW mile 6.2 East of Harvey Lock), the SR 39 (Judge Seeber/Claiborne Avenue) bridge, mile 0.9 (GIWW mile 6.7 East of Harvey Lock), and the Florida Avenue bridge, mile 1.7 (GIWW mile 7.5 East of Harvey...

  11. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Harbor Navigation Canal, New Orleans. (a) The draws of the SR 46 (St. Claude Avenue) bridge, mile 0.5 (GIWW mile 6.2 East of Harvey Lock), the SR 39 (Judge Seeber/Claiborne Avenue) bridge, mile 0.9 (GIWW mile 6.7 East of Harvey Lock), and the Florida Avenue bridge, mile 1.7 (GIWW mile 7.5 East of Harvey...

  12. 33 CFR 207.420 - Chicago River, Ill.; Sanitary District controlling works, and the use, administration, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.420 Chicago River, Ill.; Sanitary... navigation. (2) Description of lock. Feet Clear length 600 Clear width 80 Depth over sills 1 24.4 1 This depth is below Chicago City Datum which is the zero of the gages mounted on the lock. The clear depth...

  13. 33 CFR 207.420 - Chicago River, Ill.; Sanitary District controlling works, and the use, administration, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.420 Chicago River, Ill.; Sanitary... navigation. (2) Description of lock. Feet Clear length 600 Clear width 80 Depth over sills 1 24.4 1 This depth is below Chicago City Datum which is the zero of the gages mounted on the lock. The clear depth...

  14. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... being made ready for entrance. A red light will indicate that the approaching vessel must wait. Whenever... lock must lie at a sufficient distance from the lock and in such a position as to leave sufficient room...

  15. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... being made ready for entrance. A red light will indicate that the approaching vessel must wait. Whenever... lock must lie at a sufficient distance from the lock and in such a position as to leave sufficient room...

  16. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... being made ready for entrance. A red light will indicate that the approaching vessel must wait. Whenever... lock must lie at a sufficient distance from the lock and in such a position as to leave sufficient room...

  17. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... being made ready for entrance. A red light will indicate that the approaching vessel must wait. Whenever... lock must lie at a sufficient distance from the lock and in such a position as to leave sufficient room...

  18. Flight Test Result for the Ground-Based Radio Navigation System Sensor with an Unmanned Air Vehicle

    PubMed Central

    Jang, Jaegyu; Ahn, Woo-Guen; Seo, Seungwoo; Lee, Jang Yong; Park, Jun-Pyo

    2015-01-01

    The Ground-based Radio Navigation System (GRNS) is an alternative/backup navigation system based on time synchronized pseudolites. It has been studied for some years due to the potential vulnerability issue of satellite navigation systems (e.g., GPS or Galileo). In the framework of our study, a periodic pulsed sequence was used instead of the randomized pulse sequence recommended as the RTCM (radio technical commission for maritime services) SC (special committee)-104 pseudolite signal, as a randomized pulse sequence with a long dwell time is not suitable for applications requiring high dynamics. This paper introduces a mathematical model of the post-correlation output in a navigation sensor, showing that the aliasing caused by the additional frequency term of a periodic pulsed signal leads to a false lock (i.e., Doppler frequency bias) during the signal acquisition process or in the carrier tracking loop of the navigation sensor. We suggest algorithms to resolve the frequency false lock issue in this paper, relying on the use of a multi-correlator. A flight test with an unmanned helicopter was conducted to verify the implemented navigation sensor. The results of this analysis show that there were no false locks during the flight test and that outliers stem from bad dilution of precision (DOP) or fluctuations in the received signal quality. PMID:26569251

  19. Investigation of air transportation technology at Ohio University, 1980. [general aviation aircraft and navigation aids

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. H.

    1981-01-01

    Specific configurations of first and second order all digital phase locked loops were analyzed for both ideal and additive gaussian noise inputs. In addition, a design for a hardware digital phase locked loop capable of either first or second order operation was evaluated along with appropriate experimental data obtained from testing of the hardware loop. All parameters chosen for the analysis and the design of the digital phase locked loop were consistent with an application to an Omega navigation receiver although neither the analysis nor the design are limited to this application. For all cases tested, the experimental data showed close agreement with the analytical results indicating that the Markov chain model for first and second order digital phase locked loops are valid.

  20. 33 CFR 165.838 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, New Orleans...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... before closure of the navigational structures, all floating vessels must depart the RNA except as follows... Harbor Navigation Canal, New Orleans, LA. (a) Location. The following is a regulated navigation area (RNA... West of Harvey Locks (WHL) (b) Definitions. As used in this section: (1) Breakaway means a floating...

  1. 33 CFR 207.249 - Ouachita and Black Rivers, Ark. and La., Mile 0.0 to Mile 338.0 (Camden, Ark.) above the mouth of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... signals, as follows: (i) One green light to indicate that the lock is open to approaching navigation. (ii... the banks, lock entrances, locks, cribs, dams, piers, fences, trees, buildings, or any other property...

  2. 33 CFR 207.187 - Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Colorado River Locks at Mile 400.8 and Mile 441.5, respectively, west of Harvey Lock, La., on the Gulf...) Unlimited passage. The floodgates and locks shall be opened for the passage of single vessels and towboats with single or multiple barges when the current in the river is less than 2 miles per hour and the head...

  3. 33 CFR 207.187 - Gulf Intracoastal Waterway, Tex.; special floodgate, lock and navigation regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Colorado River Locks at Mile 400.8 and Mile 441.5, respectively, west of Harvey Lock, La., on the Gulf...) Unlimited passage. The floodgates and locks shall be opened for the passage of single vessels and towboats with single or multiple barges when the current in the river is less than 2 miles per hour and the head...

  4. Design of Lockage Waiting Areas at L.S.A.F. (Lower Saint Anthony Falls) Lock, Lock Number 2, and Lock Number 3, Upper Mississippi River.

    DTIC Science & Technology

    1980-01-01

    RIVER. 41. PKRFORING ORG. REPORT Nme T% AUTNOR(q) S. CONTRACT OR GRANT NUNUERfa) DACW37-77-C-0148 PERORING ORGANIZATION NAME AND ADDRESS 10. PRGRAM ... prevent erosion. The other facilities provided 7 will be navigation buoys, a lockage waiting area sign, and two trash receptacles. LOCK 2. UPPER APPROACH

  5. Navy Supplement to the DOD Dictionary of Military and Associated Terms

    DTIC Science & Technology

    2012-06-01

    rate LI interference level LI/ LO lock-in/lock-out LIA laser illuminator assembly LIC low-intensity conflict lidar laser identification, detection, and...liaison officer LO locked open; low observable; lubricating oil fill, transfer and purification LO /LI lock-out/lock-in LO / LO lift-on/lift-off LOA letter...aid to navigation LOS launch on search; law of the sea; line of sight; line of sound; lubricating oil service, main LOT letter of transmittal LOTS

  6. Robust low-frequency spread-spectrum navigation system

    DOEpatents

    Smith, Stephen F [Loudon, TN; Moore, James A [Powell, TN

    2012-01-03

    Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

  7. Robust low-frequency spread-spectrum navigation system

    DOEpatents

    Smith, Stephen F [Loudon, TN; Moore, James A [Powell, TN

    2011-01-25

    Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

  8. Robust low-frequency spread-spectrum navigation system

    DOEpatents

    Smith, Stephen F; Moore, James A

    2012-10-30

    Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

  9. Robust low-frequency spread-spectrum navigation system

    DOEpatents

    Smith, Stephen F [Loudon, TN; Moore, James A [Powell, TN

    2009-12-01

    Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

  10. Preliminary Marine Safety Risk Assessment, Brandon Road Lock and Dam Invasive Species Control Measures

    DTIC Science & Technology

    2016-12-01

    i Classification | CG-926 RDC | author | audience | month year Preliminary Marine Safety Risk Assessment, Brandon Road Lock & Dam...No. 4. Title and Subtitle Preliminary Marine Safety Risk Assessment, Brandon Road Lock & Dam Invasive Species Control Measures 5. Report Date...safety due to proposed invasive species control measures located in the vicinity of the Brandon Road Lock and Dam (BRLD) Navigation Project on the

  11. Deterioration and Repair of Concrete in the Lower Monumental Navigation Lock Wall.

    DTIC Science & Technology

    1981-06-01

    Lewiston , ID, along the Columbia and Snake Rivers. Because there are no alternate waterways or lock, the transportation system stops if the lock is...tem 3 Page 1 of 1 LOWER SNAKE RIVER PROJECT LOWERGRANITE 7.0 Lewiston LFliLE GOOSE C LOWER ~ MONUMENTAL ~rDN LCOWER SNAKE Tri-cites ICE HAROBO R ASH

  12. 33 CFR 207.460 - Fox River, Wis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DEFENSE NAVIGATION REGULATIONS § 207.460 Fox River, Wis. (a) Use, administration and navigation of the... enter a canal or lock whose actual draft exceeds the least depth of water in the channel of the canal as...

  13. 33 CFR 207.460 - Fox River, Wis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DEFENSE NAVIGATION REGULATIONS § 207.460 Fox River, Wis. (a) Use, administration and navigation of the... enter a canal or lock whose actual draft exceeds the least depth of water in the channel of the canal as...

  14. Aquatic habitat change in the Arkansas river after the development of a lock-and-dam commercial navigation system

    USGS Publications Warehouse

    Schramm, H.L.; Minnis, R.B.; Spencer, A.B.; Theel, R.T.

    2008-01-01

    The McClellan-Kerr Arkansas River Navigation System (MKARNS), completed in 1971, required the construction of 17 locks and dams and associated navigation works to make the Arkansas and Verdigris Rivers navigable for barge traffic from the Mississippi River to Catoosa, Oklahoma. We used a Geographic Information System to assess habitat changes in the 477-km portion of this system within Arkansas from 1973 to 1999. Total aquatic area declined by 9% from 42 404 to 38 655 ha. Aquatic habitat losses were 1-17% among pools. Greatest habitat losses occurred in diked secondary channels (former secondary channels with flow reduced by rock dikes) and backwaters adjacent to the main channel. Most of the area of dike pools (aquatic habitat downstream of rock dikes), diked secondary channels and adjacent backwaters were <0.9 m deep. Copyright ?? 2008 John Wiley & Sons, Ltd.

  15. 33 CFR 207.476 - The Inland Route-lock in Crooked River, Alanson, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...

  16. 33 CFR 207.476 - The Inland Route-lock in Crooked River, Alanson, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...

  17. 33 CFR 207.476 - The Inland Route-lock in Crooked River, Alanson, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...

  18. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Vessels arriving at these markers or the mooring cells immediately upstream and downstream of the lock... mooring facilities at the junction of main stem and secondary channels are to provide temporary mooring...

  19. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.275... be reported to the nearest lock and the appropriate U.S. Coast Guard Office. The report shall include.... The lockmaster shall be kept informed of the progress being made in bringing the barges under control...

  20. 33 CFR 207.300 - Ohio River, Mississippi River above Cairo, Ill., and their tributaries; use, administration, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... reported to the nearest lock. The report shall include information as to the number of loose barges, their... of the progress being made in bringing the barges under control so that he can initiate whatever...

  1. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.275... be reported to the nearest lock and the appropriate U.S. Coast Guard Office. The report shall include.... The lockmaster shall be kept informed of the progress being made in bringing the barges under control...

  2. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.275... be reported to the nearest lock and the appropriate U.S. Coast Guard Office. The report shall include.... The lockmaster shall be kept informed of the progress being made in bringing the barges under control...

  3. 33 CFR 207.300 - Ohio River, Mississippi River above Cairo, Ill., and their tributaries; use, administration, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... reported to the nearest lock. The report shall include information as to the number of loose barges, their... of the progress being made in bringing the barges under control so that he can initiate whatever...

  4. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.275... be reported to the nearest lock and the appropriate U.S. Coast Guard Office. The report shall include.... The lockmaster shall be kept informed of the progress being made in bringing the barges under control...

  5. 33 CFR 207.300 - Ohio River, Mississippi River above Cairo, Ill., and their tributaries; use, administration, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... reported to the nearest lock. The report shall include information as to the number of loose barges, their... of the progress being made in bringing the barges under control so that he can initiate whatever...

  6. Videoexoscopic real-time intraoperative navigation for spinal neurosurgery: a novel co-adaptation of two existing technology platforms, technical note.

    PubMed

    Huang, Meng; Barber, Sean Michael; Steele, William James; Boghani, Zain; Desai, Viren Rajendrakumar; Britz, Gavin Wayne; West, George Alexander; Trask, Todd Wilson; Holman, Paul Joseph

    2018-06-01

    Image-guided approaches to spinal instrumentation and interbody fusion have been widely popularized in the last decade [1-5]. Navigated pedicle screws are significantly less likely to breach [2, 3, 5, 6]. Navigation otherwise remains a point reference tool because the projection is off-axis to the surgeon's inline loupe or microscope view. The Synaptive robotic brightmatter drive videoexoscope monitor system represents a new paradigm for off-axis high-definition (HD) surgical visualization. It has many advantages over the traditional microscope and loupes, which have already been demonstrated in a cadaveric study [7]. An auxiliary, but powerful capability of this system is projection of a second, modifiable image in a split-screen configuration. We hypothesized that integration of both Medtronic and Synaptive platforms could permit the visualization of reconstructed navigation and surgical field images simultaneously. By utilizing navigated instruments, this configuration has the ability to support live image-guided surgery or real-time navigation (RTN). Medtronic O-arm/Stealth S7 navigation, MetRx, NavLock, and SureTrak spinal systems were implemented on a prone cadaveric specimen with a stream output to the Synaptive Display. Surgical visualization was provided using a Storz Image S1 platform and camera mounted to the Synaptive robotic brightmatter drive. We were able to successfully technically co-adapt both platforms. A minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and an open pedicle subtraction osteotomy (PSO) were performed using a navigated high-speed drill under RTN. Disc Shaver and Trials under RTN were implemented on the MIS TLIF. The synergy of Synaptive HD videoexoscope robotic drive and Medtronic Stealth platforms allow for live image-guided surgery or real-time navigation (RTN). Off-axis projection also allows upright neutral cervical spine operative ergonomics for the surgeons and improved surgical team visualization and education compared to traditional means. This technique has the potential to augment existing minimally invasive and open approaches, but will require long-term outcome measurements for efficacy.

  7. 33 CFR 165.838 - Regulated Navigation Area; New Orleans Area of Responsibility, New Orleans, LA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the RNA, or as authorized by a waiver approved by the COTP in accordance with paragraph (d) of this... as the malfunction of a bridge or lock within the RNA, the person in charge of a vessel may orally.... (a) Regulated Navigation Area. The following is a regulated navigation area (RNA): (1) The Inner...

  8. 33 CFR 165.838 - Regulated Navigation Area; New Orleans Area of Responsibility, New Orleans, LA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the RNA, or as authorized by a waiver approved by the COTP in accordance with paragraph (d) of this... as the malfunction of a bridge or lock within the RNA, the person in charge of a vessel may orally.... (a) Regulated Navigation Area. The following is a regulated navigation area (RNA): (1) The Inner...

  9. 33 CFR 165.838 - Regulated Navigation Area; New Orleans Area of Responsibility, New Orleans, LA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the RNA, or as authorized by a waiver approved by the COTP in accordance with paragraph (d) of this... as the malfunction of a bridge or lock within the RNA, the person in charge of a vessel may orally.... (a) Regulated Navigation Area. The following is a regulated navigation area (RNA): (1) The Inner...

  10. 33 CFR 165.838 - Regulated Navigation Area; New Orleans Area of Responsibility, New Orleans, LA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the RNA, or as authorized by a waiver approved by the COTP in accordance with paragraph (d) of this... as the malfunction of a bridge or lock within the RNA, the person in charge of a vessel may orally.... (a) Regulated Navigation Area. The following is a regulated navigation area (RNA): (1) The Inner...

  11. Deformable Bullnose Energy Absorbing System (BEAS). Report 2: Head-On Impact with a Deformable BEAS and Introducing a Collapsible Arch

    DTIC Science & Technology

    2011-07-01

    gate operations at Belleville Locks and Dam. ........................... 105 Figure 5.20 The non-linear costs for full closure of the locks and dam...Super Cone Fender Front Arch Results ................................................. 96 Table 5.3 Costs Over Time for Full Closure at Particular Corps...Corps Navigation Economics PDT tabulation of costs over time for full closure at the Corps lock and dam structures. Bob Willis also supplied the

  12. A Preliminary Assessment of Corps of Engineers’ Reservoirs, Their Purposes and Susceptibility to Drought

    DTIC Science & Technology

    1990-12-01

    ROAD LOCK AND DAM ILLINOIS RIVER L IL CEDARS LOCK AND DAM (KIMBERLY DAM) FOX RIVER L WI CORALVILLE LAKE AND DAM IOWA RIVER R IA DEPERE LOCK AND DAM FOX...Mississippi upstream to Sioux City, Iowa below Gavins Point Dam. Drought results in lower streamflow and a shorter navigation season. Lower streamflow may...897 of the previous month. Classification system. Palmer (1965) used drought data from central Iowa and western Kansas to plot a graph of accumulated

  13. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the lockmaster's office. Notice to vessels desiring lockage will be given by red and green traffic lights. Vessels may enter locks on green lights, but must await green signal when lights are red...) [Reserved] (d) Trespass. No one shall trespass on the grounds or buildings, and everyone shall be deemed...

  14. 77 FR 23114 - Modification, Revocation and Establishment of Air Traffic Service Routes; Windsor Locks Area; CT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-18

    ... Traffic Service Routes; Windsor Locks Area; CT AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... coordinate for one point in the description of area navigation (RNAV) route T-300. DATES: Effective date 0901... action under 1 CFR part 51, subject to the annual revision of FAA Order 7400.9 and publication of...

  15. Analysis of first and second order binary quantized digital phase-locked loops for ideal and white Gaussian noise inputs

    NASA Technical Reports Server (NTRS)

    Blasche, P. R.

    1980-01-01

    Specific configurations of first and second order all digital phase locked loops are analyzed for both ideal and additive white gaussian noise inputs. In addition, a design for a hardware digital phase locked loop capable of either first or second order operation is presented along with appropriate experimental data obtained from testing of the hardware loop. All parameters chosen for the analysis and the design of the digital phase locked loop are consistent with an application to an Omega navigation receiver although neither the analysis nor the design are limited to this application.

  16. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... United States part and other lands, piers, buildings, water level regulation works, hydroelectric power plant, and other appurtenances acquired or constructed for the channel improvement and use of the...) Manning requirements. On all vessels of 400 gross tons or over navigating the canal under their own power...

  17. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... United States part and other lands, piers, buildings, water level regulation works, hydroelectric power plant, and other appurtenances acquired or constructed for the channel improvement and use of the...) Manning requirements. On all vessels of 400 gross tons or over navigating the canal under their own power...

  18. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Ice Harbor, WUJ 43 Lower Monumental, WUJ 44 Little Goose, or WUJ 45 Lower Granite, at least one-half... is 19 feet. When the river flow at Lower Granite exceeds 330,000 cubic feet per second the normal... Lower Granite Lock and Dam. The waters restricted to all vessels, except Government vessels, are...

  19. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ice Harbor, WUJ 43 Lower Monumental, WUJ 44 Little Goose, or WUJ 45 Lower Granite, at least one-half... is 19 feet. When the river flow at Lower Granite exceeds 330,000 cubic feet per second the normal... Lower Granite Lock and Dam. The waters restricted to all vessels, except Government vessels, are...

  20. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ice Harbor, WUJ 43 Lower Monumental, WUJ 44 Little Goose, or WUJ 45 Lower Granite, at least one-half... is 19 feet. When the river flow at Lower Granite exceeds 330,000 cubic feet per second the normal... Lower Granite Lock and Dam. The waters restricted to all vessels, except Government vessels, are...

  1. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Ice Harbor, WUJ 43 Lower Monumental, WUJ 44 Little Goose, or WUJ 45 Lower Granite, at least one-half... is 19 feet. When the river flow at Lower Granite exceeds 330,000 cubic feet per second the normal... Lower Granite Lock and Dam. The waters restricted to all vessels, except Government vessels, are...

  2. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Ice Harbor, WUJ 43 Lower Monumental, WUJ 44 Little Goose, or WUJ 45 Lower Granite, at least one-half... is 19 feet. When the river flow at Lower Granite exceeds 330,000 cubic feet per second the normal... Lower Granite Lock and Dam. The waters restricted to all vessels, except Government vessels, are...

  3. 33 CFR 207.170c - Kissimmee River, navigation locks between Lake Tohopekaliga and Lake Okeechobee, Fla.; use...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....m. Saturday and Sunday Mar. 1 through Oct. 31 5:30 a.m. to 7:30 p.m. Do Nov. 1 through Feb. 28 5:30 a.m. to 6:30 p.m. Lock S-65A Seven days a week All year 8:00 a.m. to 5:00 p.m. Locks S-65B, S-65C, and S-65D Monday through Friday All year 8:00 a.m. to 5:00 p.m. Saturday and Sunday Mar. 1 through Oct...

  4. 33 CFR 207.170c - Kissimmee River, navigation locks between Lake Tohopekaliga and Lake Okeechobee, Fla.; use...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....m. Saturday and Sunday Mar. 1 through Oct. 31 5:30 a.m. to 7:30 p.m. Do Nov. 1 through Feb. 28 5:30 a.m. to 6:30 p.m. Lock S-65A Seven days a week All year 8:00 a.m. to 5:00 p.m. Locks S-65B, S-65C, and S-65D Monday through Friday All year 8:00 a.m. to 5:00 p.m. Saturday and Sunday Mar. 1 through Oct...

  5. 33 CFR 207.170c - Kissimmee River, navigation locks between Lake Tohopekaliga and Lake Okeechobee, Fla.; use...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....m. Saturday and Sunday Mar. 1 through Oct. 31 5:30 a.m. to 7:30 p.m. Do Nov. 1 through Feb. 28 5:30 a.m. to 6:30 p.m. Lock S-65A Seven days a week All year 8:00 a.m. to 5:00 p.m. Locks S-65B, S-65C, and S-65D Monday through Friday All year 8:00 a.m. to 5:00 p.m. Saturday and Sunday Mar. 1 through Oct...

  6. 33 CFR 207.170c - Kissimmee River, navigation locks between Lake Tohopekaliga and Lake Okeechobee, Fla.; use...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....m. Saturday and Sunday Mar. 1 through Oct. 31 5:30 a.m. to 7:30 p.m. Do Nov. 1 through Feb. 28 5:30 a.m. to 6:30 p.m. Lock S-65A Seven days a week All year 8:00 a.m. to 5:00 p.m. Locks S-65B, S-65C, and S-65D Monday through Friday All year 8:00 a.m. to 5:00 p.m. Saturday and Sunday Mar. 1 through Oct...

  7. 33 CFR 207.170c - Kissimmee River, navigation locks between Lake Tohopekaliga and Lake Okeechobee, Fla.; use...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....m. Saturday and Sunday Mar. 1 through Oct. 31 5:30 a.m. to 7:30 p.m. Do Nov. 1 through Feb. 28 5:30 a.m. to 6:30 p.m. Lock S-65A Seven days a week All year 8:00 a.m. to 5:00 p.m. Locks S-65B, S-65C, and S-65D Monday through Friday All year 8:00 a.m. to 5:00 p.m. Saturday and Sunday Mar. 1 through Oct...

  8. Design and Implementation of an RTK-Based Vector Phase Locked Loop

    PubMed Central

    Shafaati, Ahmad; Lin, Tao; Broumandan, Ali; Lachapelle, Gérard

    2018-01-01

    This paper introduces a novel double-differential vector phase-locked loop (DD-VPLL) for Global Navigation Satellite Systems (GNSS) that leverages carrier phase position solutions as well as base station measurements in the estimation of rover tracking loop parameters. The use of double differencing alleviates the need for estimating receiver clock dynamics and atmospheric delays; therefore, the navigation filter consists of the baseline dynamic states only. It is shown that using vector processing for carrier phase tracking leads to a significant enhancement in the receiver sensitivity compared to using the conventional scalar-based tracking loop (STL) and vector frequency locked loop (VFLL). The sensitivity improvement of 8 to 10 dB compared to STL, and 7 to 8 dB compared to VFLL, is obtained based on the test cases reported in the paper. Also, an increased probability of ambiguity resolution in the proposed method results in better availability for real time kinematic (RTK) applications. PMID:29533994

  9. 78 FR 34255 - Regulated Navigation Area; Vessel Traffic in Vicinity of Marseilles Dam; Illinois River

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ...-0300 prior to processing through Lock and Dams within the RNA as follows: (i) Northbound vessels must... Navigation Area (RNA) on the Illinois River. This Temporary Final Rule stipulates operational requirements... Mile Marker 240.0 to Mile Marker 271.4. This RNA is necessary to protect the general public, vessels...

  10. Low cost omega navigation receiver

    NASA Technical Reports Server (NTRS)

    Lilley, R. W.

    1974-01-01

    The development of a low cost Omega navigation receiver is discussed. Emphasis is placed on the completion and testing of a modular, multipurpose Omega receiver which utilizes a digital memory-aided, phase-locked loop to provide phase measurement data to a variety of applications interfaces. The functional units contained in the prototype device are described. The receiver is capable of receiving and storing phase measurements for up to eight Omega signals and computes two switch-selectable lines of position, displaying this navigation data in chart-recorded form.

  11. 33 CFR Appendix I to Subpart A of... - Vessel Dimensions

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Vessel Dimensions I Appendix I to... Subpart A of Part 401—Vessel Dimensions Structures are located at a number of Seaway locks which, when... of 23.2 m. For vessels that have a beam width less than this and that have dimensions exceeding the...

  12. 33 CFR Appendix I to Subpart A of... - Vessel Dimensions

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Vessel Dimensions I Appendix I to... Subpart A of Part 401—Vessel Dimensions Structures are located at a number of Seaway locks which, when... of 23.2 m. For vessels that have a beam width less than this and that have dimensions exceeding the...

  13. 33 CFR Appendix I to Subpart A of... - Vessel Dimensions

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Vessel Dimensions I Appendix I to... Subpart A of Part 401—Vessel Dimensions Structures are located at a number of Seaway locks which, when... of 23.2 m. For vessels that have a beam width less than this and that have dimensions exceeding the...

  14. 33 CFR Appendix I to Subpart A of... - Vessel Dimensions

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Vessel Dimensions I Appendix I to... Subpart A of Part 401—Vessel Dimensions Structures are located at a number of Seaway locks which, when... of 23.2 m. For vessels that have a beam width less than this and that have dimensions exceeding the...

  15. 33 CFR Appendix I to Subpart A of... - Vessel Dimensions

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Vessel Dimensions I Appendix I to... Subpart A of Part 401—Vessel Dimensions Structures are located at a number of Seaway locks which, when... of 23.2 m. For vessels that have a beam width less than this and that have dimensions exceeding the...

  16. Hidden attractors in dynamical models of phase-locked loop circuits: Limitations of simulation in MATLAB and SPICE

    NASA Astrophysics Data System (ADS)

    Kuznetsov, N. V.; Leonov, G. A.; Yuldashev, M. V.; Yuldashev, R. V.

    2017-10-01

    During recent years it has been shown that hidden oscillations, whose basin of attraction does not overlap with small neighborhoods of equilibria, may significantly complicate simulation of dynamical models, lead to unreliable results and wrong conclusions, and cause serious damage in drilling systems, aircrafts control systems, electromechanical systems, and other applications. This article provides a survey of various phase-locked loop based circuits (used in satellite navigation systems, optical, and digital communication), where such difficulties take place in MATLAB and SPICE. Considered examples can be used for testing other phase-locked loop based circuits and simulation tools, and motivate the development and application of rigorous analytical methods for the global analysis of phase-locked loop based circuits.

  17. [Electromagnetic navigation interlocking intramedullary nail technology for treatment of femoral shaft fractures].

    PubMed

    Zuo, Kangkang; Qin, Wei; Guo, Qing; Palati-Ababaikeli; Qiao, Peiliu; Shen, Mingquan; Yin, Lele; Pan, Qilin; Xu, Xiaoxiong

    2014-10-01

    To explore the value of electromagnetic navigation interlocking intramedullary nail in the treatment of femoral shaft fracture. Between July 2012 and October 2013, 53 cases of femoral shaft fracture were treated. There were 40 males and 13 females, aged 16-52 years (mean, 38.3 years). The causes of injury were traffic accident in 28 cases, falling from height in 11 cases, falling in 7 cases, crush injury in 4 cases, and other in 3 cases. Of 53 cases, there were 3 cases of open fracture (Gustilo I degree) and 50 cases of closed fracture. Fracture was located in the proximal femur in 17 cases, middle femur in 29 cases, and distal femur in 7 cases. According to Winquist classification, 7 cases were rated as type I, 8 cases as type II, 22 cases as type III, and 16 cases as type IV; according to AO classification, 18 cases were rated as type 32-A, 28 cases as type 32-B, and 7 cases as type 32-C. The time from injury to operation was 3-11 days (mean, 5 days). Distal interlocking intramedullary nail was implanted using electromagnetic navigation. The distal locking nail operation with interlocking intramedullary nail was successfully completed under electromagnetic navigation; the one-time success rate of distal locking nail operation reached 100%; and the locking nail time was 5.0-9.5 minutes (mean, 7.0 minutes). Healing of incision by first intention was obtained after operation, and no complication of skin necrosis, infection, and sinus tract occurred. Fifty-three cases were all followed up 5-12 months (mean, 9 months). One case had hip pain and weaken middle gluteal muscle strength, and the symptoms disappeared after removing the nail. During the follow-up period, no broken nails, nail exit, infection, or re-fracture occurred. All fractures achieved clinical healing, and the healing time was 8-22 weeks (mean, 14.5 weeks). In 49 patients followed up 8 months, the Lysholm score was excellent in 44 cases, good in 4 cases, and acceptable in 1 case, with an excellent and good rate of 98%. Electromagnetic navigation system is safe and reliable, with the advantages of high positioning accuracy, short operation time, and no radiation, the clinical application of the system for distal locking nail operation can obtain excellent short-term effectiveness.

  18. Digital correlation detector for low-cost Omega navigation

    NASA Technical Reports Server (NTRS)

    Chamberlin, K. A.

    1976-01-01

    Techniques to lower the cost of using the Omega global navigation network with phase-locked loops (PLL) were developed. The technique that was accepted as being "optimal" is called the memory-aided phase-locked loop (MAPLL) since it allows operation on all eight Omega time slots with one PLL through the implementation of a random access memory. The receiver front-end and the signals that it transmits to the PLL were first described. A brief statistical analysis of these signals was then made to allow a rough comparison between the front-end presented in this work and a commercially available front-end to be made. The hardware and theory of application of the MAPLL were described, ending with an analysis of data taken with the MAPLL. Some conclusions and recommendations were also given.

  19. Mobility platform coupling device and method for coupling mobility platforms

    DOEpatents

    Shirey, David L.; Hayward, David R.; Buttz, James H.

    2002-01-01

    A coupling device for connecting a first mobility platform to a second mobility platform in tandem. An example mobility platform is a robot. The coupling device has a loose link mode for normal steering conditions and a locking position, tight link mode for navigation across difficult terrain and across obstacles, for traversing chasms, and for navigating with a reduced footprint in tight steering conditions.

  20. Rehabilitation of Navigation Lock Walls: Case Histories

    DTIC Science & Technology

    1987-12-01

    built prior to 1940. The average age of these 133 older lock chambers is nearly 67 years or well beyond the 50-year design ser-vice life. Since these...been to treat the projects as new work. Procedures followed for concrete operations have been those with which designers and contractors are familiar...c) discussion with project personnel, and (d) discussion wit h designers and contractors. Although the information obtained from the vario us

  1. Computer program CORDET. [computerized simulation of digital phase-lock loop for Omega navigation receiver

    NASA Technical Reports Server (NTRS)

    Palkovic, R. A.

    1974-01-01

    A FORTRAN 4 computer program provides convenient simulation of an all-digital phase-lock loop (DPLL). The DPLL forms the heart of the Omega navigation receiver prototype. Through the DPLL, the phase of the 10.2 KHz Omega signal is estimated when the true signal phase is contaminated with noise. This investigation has provided a convenient means of evaluating loop performance in a variety of noise environments, and has proved to be a useful tool for evaluating design changes. The goals of the simulation are to: (1) analyze the circuit on a bit-by-bit level in order to evaluate the overall design; (2) see easily the effects of proposed design changes prior to actual breadboarding; and (3) determine the optimum integration time for the DPLL in an environment typical of general aviation conditions.

  2. Analysis of Recreational Boating Impact on Navigation Lock Performance

    DTIC Science & Technology

    1989-12-01

    seeing the large craft at night. Another comment, a common one at most locks, was the lack of knowledge of rules by many recreational boaters. Several...cause of time delays, and not recreational boats. However, one of the pilots indicated that water skiers were major hazards to commercial barges as...they cut across the path of commercial tows below the line of sight of the pilot. Recreational boaters and particularly those pulling skiers should be

  3. Engineering and Design: Control Stations and Control Systems for Navigation Locks and Dams

    DTIC Science & Technology

    1997-05-30

    of human intelli- hypothetical lock and dam configurations. Finally, b. Terminology. (1) PLC system. The computer- based systems utilize special...electrical industry for industrial use. There- fore, for purposes of this document, a computer- based system is referred to as a PLC system. (2) Relay- based ...be custom made, because most of today’s control systems of any complexity are PLC - based , the standard size of a given motor starter cubicle is not

  4. Intelligent personal navigator supported by knowledge-based systems for estimating dead reckoning navigation parameters

    NASA Astrophysics Data System (ADS)

    Moafipoor, Shahram

    Personal navigators (PN) have been studied for about a decade in different fields and applications, such as safety and rescue operations, security and emergency services, and police and military applications. The common goal of all these applications is to provide precise and reliable position, velocity, and heading information of each individual in various environments. In the PN system developed in this dissertation, the underlying assumption is that the system does not require pre-existing infrastructure to enable pedestrian navigation. To facilitate this capability, a multisensor system concept, based on the Global Positioning System (GPS), inertial navigation, barometer, magnetometer, and a human pedometry model has been developed. An important aspect of this design is to use the human body as navigation sensor to facilitate Dead Reckoning (DR) navigation in GPS-challenged environments. The system is designed predominantly for outdoor environments, where occasional loss of GPS lock may happen; however, testing and performance demonstration have been extended to indoor environments. DR navigation is based on a relative-measurement approach, with the key idea of integrating the incremental motion information in the form of step direction (SD) and step length (SL) over time. The foundation of the intelligent navigation system concept proposed here rests in exploiting the human locomotion pattern, as well as change of locomotion in varying environments. In this context, the term intelligent navigation represents the transition from the conventional point-to-point DR to dynamic navigation using the knowledge about the mechanism of the moving person. This approach increasingly relies on integrating knowledge-based systems (KBS) and artificial intelligence (AI) methodologies, including artificial neural networks (ANN) and fuzzy logic (FL). In addition, a general framework of the quality control for the real-time validation of the DR processing is proposed, based on a two-stage Kalman Filter approach. The performance comparison of the algorithm based on different field and simulated datasets, with varying levels of sensor errors, showed that 90 per cent success rate was achieved in detection of outliers for SL and 80 per cent for SD. The SL is predicted for both KBS-based ANN and FL approaches with an average accumulated error of 2 per cent, observed for the total distance traveled, which is generally an improvement over most of the existing pedometry systems. The target accuracy of the system is +/-(3-5)m CEP50 (circular error, probable 50%). This dissertation provides a performance analysis in the outdoor and indoor environments for different operators. Another objective of this dissertation is to test the system's navigation limitation in DR mode in terms of time and trajectory length in order to determine the upper limit of indoor operations. It was determined that for more than four indoor loops, where the user walked 261m in about 6.5 minutes, the DR performance met the required accuracy specifications. However, these results are only relevant to the existing data. Future studies should consider more comprehensive performance analysis for longer trajectories in challenging environments and possible extension to image-based navigation to expand the indoor capability of the system.

  5. 43 CFR 423.38 - Operating vessels on Reclamation waters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... official. (i) You must not attach or anchor a vessel to structures such as locks, dams, regulatory or navigational buoys, or other structures not designed for such purpose. (j) You must display an international...

  6. 43 CFR 423.38 - Operating vessels on Reclamation waters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... official. (i) You must not attach or anchor a vessel to structures such as locks, dams, regulatory or navigational buoys, or other structures not designed for such purpose. (j) You must display an international...

  7. Evaluation of the National Register Eligibility of the Inner Harbor Navigation Canal Lock in Orleans Parish, Louisiana.

    DTIC Science & Technology

    1987-06-15

    INTRODUCTIONo ....... .. .......... _..*.. ........ o... 19 The Inner Harbor Navigation Canal Complex............19 Sources Used During Research...PAGE BLANK Sources Used During Research The archival sources utilized during the research for the project include: Annual Reports to the Chief of...the term used to describe a condition where the earth is eroded by an underground source of water. The effect of this type of erosion would be that

  8. Taming the Des Moines Rapids: The Background of Lock 19

    DTIC Science & Technology

    1978-06-01

    dams had been proposed at various locations, but none had ever been built. Joseph Smith and his Mormon followers at Nauvoo, Il- linois, at the head...of the rapids, had planned to build such a dam for power and navigation pur- poses in 1844, but Smith was killed and his follow- ers left for Utah...opened at 8 a.m., the Lachlan Macleay of the Federal Barge Lines entered the lock, greeted by only a handful of District employees. The tow of seven

  9. Preliminary Cultural Resource Survey and Geomorphological Assessment of Selected Areas in Navigation Pool 16, Mississippi River.

    DTIC Science & Technology

    1982-06-01

    Dated Sites in Pool 16 .............. 28 OR 2. Stream Gauge Data for Historical - Floods, Illinois and Mississippi Canal Lock 32 (U. S. Corps of...the ridge was 30 TABLE 2 STREAM GAUGE DATA FOR HISTORICAL FLOODS, ILLINOIS AND MISSISSIPPI CANAL LOCK 32 (U. S. CORPS OF ENGINEERS 1981) Rank Order of...result of back- water activity rather than active throughflow similar to that experienced in the 1890s. Judging from river gauge records dating from

  10. Study of GNSS Loss of Lock Characteristics under Ionosphere Scintillation with GNSS Data at Weipa (Australia) During Solar Maximum Phase.

    PubMed

    Liu, Yang; Fu, Lianjie; Wang, Jinling; Zhang, Chunxi

    2017-09-25

    One of the adverse impacts of scintillation on GNSS signals is the loss of lock status, which can lead to GNSS geometry and visibility reductions that compromise the accuracy and integrity of navigation performance. In this paper the loss of lock based on ionosphere scintillation in this solar maximum phase has been well investigated with respect to both temporal and spatial behaviors, based on GNSS observatory data collected at Weipa (Australia; geographic: 12.45° S, 130.95° E; geomagnetic: 21.79° S, 214.41° E) from 2011 to 2015. Experiments demonstrate that the percentage of occurrence of loss of lock events under ionosphere scintillation is closely related with solar activity and seasonal shifts. Loss of lock behaviors under ionosphere scintillation related to elevation and azimuth angles are statistically analyzed, with some distinct characteristics found. The influences of daytime scintillation and geomagnetic storms on loss of lock have also been discussed in details. The proposed work is valuable for a deeper understanding of theoretical mechanisms of-loss of lock under ionosphere scintillation in global regions, and provides a reference for GNSS applications in certain regions at Australian low latitudes.

  11. Study of GNSS Loss of Lock Characteristics under Ionosphere Scintillation with GNSS Data at Weipa (Australia) During Solar Maximum Phase

    PubMed Central

    Liu, Yang; Fu, Lianjie; Wang, Jinling; Zhang, Chunxi

    2017-01-01

    One of the adverse impacts of scintillation on GNSS signals is the loss of lock status, which can lead to GNSS geometry and visibility reductions that compromise the accuracy and integrity of navigation performance. In this paper the loss of lock based on ionosphere scintillation in this solar maximum phase has been well investigated with respect to both temporal and spatial behaviors, based on GNSS observatory data collected at Weipa (Australia; geographic: 12.45° S, 130.95° E; geomagnetic: 21.79° S, 214.41° E) from 2011 to 2015. Experiments demonstrate that the percentage of occurrence of loss of lock events under ionosphere scintillation is closely related with solar activity and seasonal shifts. Loss of lock behaviors under ionosphere scintillation related to elevation and azimuth angles are statistically analyzed, with some distinct characteristics found. The influences of daytime scintillation and geomagnetic storms on loss of lock have also been discussed in details. The proposed work is valuable for a deeper understanding of theoretical mechanisms of—loss of lock under ionosphere scintillation in global regions, and provides a reference for GNSS applications in certain regions at Australian low latitudes. PMID:28946676

  12. Reducing intraoperative duration and ionising radiation exposure during the insertion of distal locking screws of intramedullary nails: a small-scale study comparing the current fluoroscopic method against radiation-free, electromagnetic navigation.

    PubMed

    Grimwood, Darren; Harvey-Lloyd, Jane

    2016-12-01

    Intramedullary nailing is the standard surgical treatment for mid-diaphyseal fractures of long bones; however, it is also a high radiation dose procedure. Distal locking is regularly cited as a demanding element of the procedure, and there remains a reliance on X-ray fluoroscopy to locate the distal holes. A recently developed electromagnetic navigation (EMN) system allows radiation-free distal locking, with a virtual on-screen image. To compare operative duration, fluoroscopy time and radiation dose when using EMN over fluoroscopy, for the distal locking of intramedullary nails. Consecutive patients with mid-diaphyseal fractures of the tibia and femur, treatable with intramedullary nails, were prospectively enrolled during a 9-month period. The sample consisted of 29 individuals, 19 under fluoroscopic guidance and 10 utilising EMN. Participants were allocated depending on the type of intramedullary nail used and surgeon's preference. These were further divided into tibial and femoral subcategories, relative to the fracture site. EMN reduced fluoroscopy time by 49 (p = 0.038) and 28 s during tibial and femoral nailings, respectively. Radiation dose was reduced by 18 cGy/cm 2 (p = 0.046) during tibial and 181 cGy/cm 2 during femoral nailings when utilising EMN. Operative duration was 11 min slower during tibial nailings using EMN, but 38 min faster in respect of femoral nailings. This study has evidenced statistically significant reductions in both fluoroscopy time and radiation dose when using EMN for the distal locking of intramedullary nails. It is expected that overall operative duration would also decrease in line with similar studies, with increased usage and a larger sample.

  13. Weak and Dynamic GNSS Signal Tracking Strategies for Flight Missions in the Space Service Volume

    PubMed Central

    Jing, Shuai; Zhan, Xingqun; Liu, Baoyu; Chen, Maolin

    2016-01-01

    Weak-signal and high-dynamics are of two primary concerns of space navigation using GNSS (Global Navigation Satellite System) in the space service volume (SSV). The paper firstly defines a reference assumption third-order phase-locked loop (PLL) as the baseline of an onboard GNSS receiver, and proves the incompetence of this conventional architecture. Then an adaptive four-state Kalman filter (KF)-based algorithm is introduced to realize the optimization of loop noise bandwidth, which can adaptively regulate its filter gain according to the received signal power and line-of-sight (LOS) dynamics. To overcome the matter of losing lock in weak-signal and high-dynamic environments, an open loop tracking strategy aided by an inertial navigation system (INS) is recommended, and the traditional maximum likelihood estimation (MLE) method is modified in a non-coherent way by reconstructing the likelihood cost function. Furthermore, a typical mission with combined orbital maneuvering and non-maneuvering arcs is taken as a destination object to test the two proposed strategies. Finally, the experiment based on computer simulation identifies the effectiveness of an adaptive four-state KF-based strategy under non-maneuvering conditions and the virtue of INS-assisted methods under maneuvering conditions. PMID:27598164

  14. Weak and Dynamic GNSS Signal Tracking Strategies for Flight Missions in the Space Service Volume.

    PubMed

    Jing, Shuai; Zhan, Xingqun; Liu, Baoyu; Chen, Maolin

    2016-09-02

    Weak-signal and high-dynamics are of two primary concerns of space navigation using GNSS (Global Navigation Satellite System) in the space service volume (SSV). The paper firstly defines a reference assumption third-order phase-locked loop (PLL) as the baseline of an onboard GNSS receiver, and proves the incompetence of this conventional architecture. Then an adaptive four-state Kalman filter (KF)-based algorithm is introduced to realize the optimization of loop noise bandwidth, which can adaptively regulate its filter gain according to the received signal power and line-of-sight (LOS) dynamics. To overcome the matter of losing lock in weak-signal and high-dynamic environments, an open loop tracking strategy aided by an inertial navigation system (INS) is recommended, and the traditional maximum likelihood estimation (MLE) method is modified in a non-coherent way by reconstructing the likelihood cost function. Furthermore, a typical mission with combined orbital maneuvering and non-maneuvering arcs is taken as a destination object to test the two proposed strategies. Finally, the experiment based on computer simulation identifies the effectiveness of an adaptive four-state KF-based strategy under non-maneuvering conditions and the virtue of INS-assisted methods under maneuvering conditions.

  15. Natural resources technical support program. Recreational use of Chickamauga Lock, Tennessee, and recreational boaters' perceptions of lock use conflicts. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patterson, M.E.; Hammitt, W.E.; Titre, J.P.

    1992-12-01

    Recreational use of the Chickamauga Lock has more than doubled since 1984, when 3,139 recreational craft used the lock. Forty percent of the total annual use occurs during the month of June. The most common reason for heavy use during the month is to attend special events, although other locks in the Tennessee River Navigation System have also shown an increase in recreational use since 1984. Overall, the study suggests a low level of conflict between recreational and commercial users. Conflict among recreational users appears to be even less of a problem. The biggest source of conflict at the currentmore » time is not the actual delays, but recreational boaters' inability to predict whether the lock will be available for use prior to arriving at the dam. Nearly one half of the boaters indicated that this is a common problem during special events. The Corps can reduce this source of conflict to some extent by using an FM repeater to announce the estimated time of recreational and commercial lockages. A majority of the respondents supported this management alternative. The second most popular management alternative was the construction of a separate lock for commercial traffic.« less

  16. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... consists of the navigable waters of the Ohio River between McAlpine Locks (Mile 606.8) and Twelve Mile Island (Mile 593), only when the McAlpine upper pool gauge is at 13.0 feet or above. [CGD 90-020, 59 FR...

  17. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... consists of the navigable waters of the Ohio River between McAlpine Locks (Mile 606.8) and Twelve Mile Island (Mile 593), only when the McAlpine upper pool gauge is at 13.0 feet or above. [CGD 90-020, 59 FR...

  18. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... consists of the navigable waters of the Ohio River between McAlpine Locks (Mile 606.8) and Twelve Mile Island (Mile 593), only when the McAlpine upper pool gauge is at 13.0 feet or above. [CGD 90-020, 59 FR...

  19. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... consists of the navigable waters of the Ohio River between McAlpine Locks (Mile 606.8) and Twelve Mile Island (Mile 593), only when the McAlpine upper pool gauge is at 13.0 feet or above. [CGD 90-020, 59 FR...

  20. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... consists of the navigable waters of the Ohio River between McAlpine Locks (Mile 606.8) and Twelve Mile Island (Mile 593), only when the McAlpine upper pool gauge is at 13.0 feet or above. [CGD 90-020, 59 FR...

  1. Investigation of new techniques for aircraft navigation using the omega navigation

    NASA Technical Reports Server (NTRS)

    Baxa, E. G., Jr.

    1978-01-01

    An OMEGA navigation receiver with a microprocessor as the computational component was investigated. A version of the INTEL 4004 microprocessor macroassembler suitable for use on the CDC-6600 system and development of a FORTRAN IV simulator program for the microprocessor was developed. Supporting studies included development and evaluation of navigation algorithms to generate relative position information from OMEGA VLF phase measurements. Simulation studies were used to evaluate assumptions made in developing a navigation equation in OMEGA Line of Position (LOP) coordinates. Included in the navigation algorithms was a procedure for calculating a position in latitude/longitude given an OMEGA LOP fix. Implementation of a digital phase locked loop (DPLL) was evaluated on the basic of phase response characteristics over a range of input phase variations. Included also is an analytical evaluation on the basis of error probability of an algorithm for automatic time synchronization of the receiver to the OMEGA broadcast format. The use of actual OMEGA phase data and published propagation prediction corrections to determine phase velocity estimates was discussed.

  2. Discharge ratings for control gates at Mississippi River lock and dam 12, Bellevue, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.

    1986-01-01

    The water level of the navigation pools on the Mississippi River are maintained by the operation of tainter and roller gates at the locks and dams. Discharge ratings for the gates on Lock and Dam 12, at Bellevue, Iowa, were developed from current-meter discharge measurements made in the forebays of the gate structures. Methodology is given to accurately compute the gate openings of the tainter gates. Discharge coefficients, in equations that express discharge as a function of tailwater head , forebay head, and height of gate opening, were determined for conditions of submerged-orifice and fee-weir flow. A comparison of the rating discharges to the hydraulic-model rating discharges is given for submerged orifice flow for the tainter and roller gates.

  3. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... lifted. If the wind is dangerously strong, passage of the bridge shall not be attempted by large vessels... business incident to the transit. A maximum of only four (4) men will be permitted to go ashore from any...

  4. Improved Reliability Models for Mechanical and Electrical Components at Navigation Lock and Dam and Flood Risk Management Facilities

    DTIC Science & Technology

    2013-04-01

    official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT...56 A2 Mechanical system - shafts ...80 A23 Mechanical system – strut spindle pin

  5. Navigation lock for Bonneville Dam, Columbia River, Oregon. Volume II. Appendix A. Pressures during lock operations. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stockstill, R.L.; George, J.F.

    1996-09-01

    Tests were conducted on two different 1:25-scale models of the New Bonneville Lock located on the Columbia River in Oregon. The lock models were built to study the filling and emptying systems, which consisted of designs utilizing bottom longitudinal floor culverts. The first design studied, defined as the H-H pattern system, consisted of four longitudinal flood culverts in each end of the lock chamber. The second system studied had two longitudinal floor culverts in each end of the lock chamber and was defined as the H pattern system. In the H-H pattern system, the filling culverts, which were located undermore » the lock chamber floor, connected to a crossover culvert with a horizontal splitter wall dividing the flow to upstream and downstream splitter manifolds were equal divisions led into four longitudinal flood culverts in each end of the lock chamber. With the type 6 (recommended) design and a 1-min valve opening time, the lock chamber filled in 8.7 min and emptied in 12.1 min. Due to differences in friction losses, the prototype can be expected to fill and empty about 20 percent faster than the model (7.0 min and 9.7 min, respectively). Modifications involving installing a slope in the lower sill and a v-notch design in the high sill were significant factors that resulted in fast filling and emptying times, low hawser forces, and only minor movement with various tow arrangements for different operating scenarios.« less

  6. Real-time method for motion-compensated MR thermometry and MRgHIFU treatment in abdominal organs.

    PubMed

    Celicanin, Zarko; Auboiroux, Vincent; Bieri, Oliver; Petrusca, Lorena; Santini, Francesco; Viallon, Magalie; Scheffler, Klaus; Salomir, Rares

    2014-10-01

    Magnetic resonance-guided high-intensity focused ultrasound is considered to be a promising treatment for localized cancer in abdominal organs such as liver, pancreas, or kidney. Abdominal motion, anatomical arrangement, and required sustained sonication are the main challenges. MR acquisition consisted of thermometry performed with segmented gradient-recalled echo echo-planar imaging, and a segment-based one-dimensional MR navigator parallel to the main axis of motion to track the organ motion. This tracking information was used in real-time for: (i) prospective motion correction of MR thermometry and (ii) HIFU focal point position lock-on target. Ex vivo experiments were performed on a sheep liver and a turkey pectoral muscle using a motion demonstrator, while in vivo experiments were conducted on two sheep liver. Prospective motion correction of MR thermometry yielded good signal-to-noise ratio (range, 25 to 35) and low geometric distortion due to the use of segmented EPI. HIFU focal point lock-on target yielded isotropic in-plane thermal build-up. The feasibility of in vivo intercostal liver treatment was demonstrated in sheep. The presented method demonstrated in moving phantoms and breathing sheep accurate motion-compensated MR thermometry and precise HIFU focal point lock-on target using only real-time pencil-beam navigator tracking information, making it applicable without any pretreatment data acquisition or organ motion modeling. Copyright © 2013 Wiley Periodicals, Inc.

  7. 75 FR 78601 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from... Harvey Lock), at New Orleans, Orleans Parish, Louisiana. This deviation is necessary to adjust the...

  8. Engagement of neural circuits underlying 2D spatial navigation in a rodent virtual reality system

    PubMed Central

    Aronov, Dmitriy; Tank, David W.

    2015-01-01

    SUMMARY Virtual reality (VR) enables precise control of an animal’s environment and otherwise impossible experimental manipulations. Neural activity in navigating rodents has been studied on virtual linear tracks. However, the spatial navigation system’s engagement in complete two-dimensional environments has not been shown. We describe a VR setup for rats, including control software and a large-scale electrophysiology system, which supports 2D navigation by allowing animals to rotate and walk in any direction. The entorhinal-hippocampal circuit, including place cells, grid cells, head direction cells and border cells, showed 2D activity patterns in VR similar to those in the real world. Hippocampal neurons exhibited various remapping responses to changes in the appearance or the shape of the virtual environment, including a novel form in which a VR-induced cue conflict caused remapping to lock to geometry rather than salient cues. These results suggest a general-purpose tool for novel types of experimental manipulations in navigating rats. PMID:25374363

  9. 76 FR 48840 - Lock+TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... Lock and Dam No. 5; (2) a 109-foot- wide, 40-foot-high lock frame module placed east of the movable... the grid. Each lock frame module would consist of ten 7-foot-diameter hydropower turbines each rated... the powerhouse on the east section of the dam in the existing levee of the east abutment; (2) a...

  10. An Adaptive INS-Aided PLL Tracking Method for GNSS Receivers in Harsh Environments.

    PubMed

    Cong, Li; Li, Xin; Jin, Tian; Yue, Song; Xue, Rui

    2016-01-23

    As the weak link in global navigation satellite system (GNSS) signal processing, the phase-locked loop (PLL) is easily influenced with frequent cycle slips and loss of lock as a result of higher vehicle dynamics and lower signal-to-noise ratios. With inertial navigation system (INS) aid, PLLs' tracking performance can be improved. However, for harsh environments with high dynamics and signal attenuation, the traditional INS-aided PLL with fixed loop parameters has some limitations to improve the tracking adaptability. In this paper, an adaptive INS-aided PLL capable of adjusting its noise bandwidth and coherent integration time has been proposed. Through theoretical analysis, the relation between INS-aided PLL phase tracking error and carrier to noise density ratio (C/N₀), vehicle dynamics, aiding information update time, noise bandwidth, and coherent integration time has been built. The relation formulae are used to choose the optimal integration time and bandwidth for a given application under the minimum tracking error criterion. Software and hardware simulation results verify the correctness of the theoretical analysis, and demonstrate that the adaptive tracking method can effectively improve the PLL tracking ability and integrated GNSS/INS navigation performance. For harsh environments, the tracking sensitivity is increased by 3 to 5 dB, velocity errors are decreased by 36% to 50% and position errors are decreased by 6% to 24% when compared with other INS-aided PLL methods.

  11. Attenuating Stereo Pixel-Locking via Affine Window Adaptation

    NASA Technical Reports Server (NTRS)

    Stein, Andrew N.; Huertas, Andres; Matthies, Larry H.

    2006-01-01

    For real-time stereo vision systems, the standard method for estimating sub-pixel stereo disparity given an initial integer disparity map involves fitting parabolas to a matching cost function aggregated over rectangular windows. This results in a phenomenon known as 'pixel-locking,' which produces artificially-peaked histograms of sub-pixel disparity. These peaks correspond to the introduction of erroneous ripples or waves in the 3D reconstruction of truly Rat surfaces. Since stereo vision is a common input modality for autonomous vehicles, these inaccuracies can pose a problem for safe, reliable navigation. This paper proposes a new method for sub-pixel stereo disparity estimation, based on ideas from Lucas-Kanade tracking and optical flow, which substantially reduces the pixel-locking effect. In addition, it has the ability to correct much larger initial disparity errors than previous approaches and is more general as it applies not only to the ground plane.

  12. 33 CFR 175.135 - Existing equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Existing equipment. 175.135 Section 175.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.135 Existing equipment. Launchers...

  13. 33 CFR 175.135 - Existing equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Existing equipment. 175.135 Section 175.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.135 Existing equipment. Launchers...

  14. 33 CFR 175.135 - Existing equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Existing equipment. 175.135 Section 175.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.135 Existing equipment. Launchers...

  15. 33 CFR 175.135 - Existing equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Existing equipment. 175.135 Section 175.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.135 Existing equipment. Launchers...

  16. 33 CFR 175.135 - Existing equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Existing equipment. 175.135 Section 175.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.135 Existing equipment. Launchers...

  17. Demonstration of Remotely Operated Vehicles to Aid Underwater Inspection of Corps of Engineers Navigation Structures. Winfield Locks and Dam 13-17 August 2007

    DTIC Science & Technology

    2008-09-01

    2 Deep Ocean Engineering Triggerfish ...Figures Figure 1. Deep Ocean Engineering Triggerfish ROV carried by two divers (top)................................... 4 Figure 2. SeaBotix...the physical parameters and approximate costs of the systems as tested. Deep Ocean Engineering Triggerfish Figure 1 shows the Deep Ocean

  18. Phase-locking of bursting neuronal firing to dominant LFP frequency components.

    PubMed

    Constantinou, Maria; Elijah, Daniel H; Squirrell, Daniel; Gigg, John; Montemurro, Marcelo A

    2015-10-01

    Neuronal firing in the hippocampal formation relative to the phase of local field potentials (LFP) has a key role in memory processing and spatial navigation. Firing can be in either tonic or burst mode. Although bursting neurons are common in the hippocampal formation, the characteristics of their locking to LFP phase are not completely understood. We investigated phase-locking properties of bursting neurons using simulations generated by a dual compartmental model of a pyramidal neuron adapted to match the bursting activity in the subiculum of a rat. The model was driven with stochastic input signals containing a power spectral profile consistent with physiologically relevant frequencies observed in LFP. The single spikes and spike bursts fired by the model were locked to a preferred phase of the predominant frequency band where there was a peak in the power of the driving signal. Moreover, the preferred phase of locking shifted with increasing burst size, providing evidence that LFP phase can be encoded by burst size. We also provide initial support for the model results by analysing example data of spontaneous LFP and spiking activity recorded from the subiculum of a single urethane-anaesthetised rat. Subicular neurons fired single spikes, two-spike bursts and larger bursts that locked to a preferred phase of either dominant slow oscillations or theta rhythms within the LFP, according to the model prediction. Both power-modulated phase-locking and gradual shift in the preferred phase of locking as a function of burst size suggest that neurons can use bursts to encode timing information contained in LFP phase into a spike-count code. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  19. Observation of High-Order Polarization-Locked Vector Solitons in a Fiber Laser

    NASA Astrophysics Data System (ADS)

    Tang, D. Y.; Zhang, H.; Zhao, L. M.; Wu, X.

    2008-10-01

    We report on the experimental observation of a new type of polarization-locked vector soliton in a passively mode-locked fiber laser. The vector soliton is characterized by the fact that not only are the two orthogonally polarized soliton components phase-locked, but also one of the components has a double-humped intensity profile. Multiple phase-locked high-order vector solitons with identical soliton parameters and harmonic mode locking of the vector solitons were also obtained in the laser. Numerical simulations confirmed the existence of stable high-order vector solitons in the fiber laser.

  20. Observation of high-order polarization-locked vector solitons in a fiber laser.

    PubMed

    Tang, D Y; Zhang, H; Zhao, L M; Wu, X

    2008-10-10

    We report on the experimental observation of a new type of polarization-locked vector soliton in a passively mode-locked fiber laser. The vector soliton is characterized by the fact that not only are the two orthogonally polarized soliton components phase-locked, but also one of the components has a double-humped intensity profile. Multiple phase-locked high-order vector solitons with identical soliton parameters and harmonic mode locking of the vector solitons were also obtained in the laser. Numerical simulations confirmed the existence of stable high-order vector solitons in the fiber laser.

  1. 78 FR 77115 - Lock 14 Hydro Partners; Notice of Application Ready for Environmental Analysis and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ...: Federal Power Act, 16 U.S.C. 791(a)-825(r). h. Applicant Contact: David Brown Kinloch, Lock 14 Hydro... of: (1) An existing 248-foot- long, 17-foot-high concrete lock and dam with a 319-foot-long stone...

  2. 33 CFR 329.9 - Time at which commerce exists or determination is made.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Time at which commerce exists or... commerce exists or determination is made. (a) Past use. A waterbody which was navigable in its natural or...) retains its character as “navigable in law” even though it is not presently used for commerce, or is...

  3. 33 CFR 329.9 - Time at which commerce exists or determination is made.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Time at which commerce exists or... commerce exists or determination is made. (a) Past use. A waterbody which was navigable in its natural or...) retains its character as “navigable in law” even though it is not presently used for commerce, or is...

  4. 33 CFR 329.9 - Time at which commerce exists or determination is made.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Time at which commerce exists or... commerce exists or determination is made. (a) Past use. A waterbody which was navigable in its natural or...) retains its character as “navigable in law” even though it is not presently used for commerce, or is...

  5. A Rating System for the Concrete in Navigation Lock Monoliths. Repair, Evaluation, Maintenance, and Rehabilitation Research Program

    DTIC Science & Technology

    1989-05-01

    surface of concrete, shaped like an icicle. A.2.14. Stalagmite : As stalactite , but upward formation. ITU A.2.15. Dusting: The development of a pow...area: Area of concrete suir- 4 face which gives off a hollow sound when struck. A.2.13. Stalactite : A downward pointing for- mation, hanging from the

  6. Atmospheric Propagation and Combining of High-Power Lasers

    DTIC Science & Technology

    2015-09-08

    Brightness-scaling potential of actively phase- locked solid state laser arrays,” IEEE J. Sel. Topics Quantum Electron., vol. 13, no. 3, pp. 460–472, May...attempting to phase- lock high-power lasers, which is not encountered when phase- locking low-power lasers, for example mW power levels. Regardless, we...technology does not currently exist. This presents a challenging problem when attempting to phase- lock high-power lasers, which is not encountered when

  7. Mode-locking behavior of Izhikevich neurons under periodic external forcing

    NASA Astrophysics Data System (ADS)

    Farokhniaee, AmirAli; Large, Edward W.

    2017-06-01

    Many neurons in the auditory system of the brain must encode periodic signals. These neurons under periodic stimulation display rich dynamical states including mode locking and chaotic responses. Periodic stimuli such as sinusoidal waves and amplitude modulated sounds can lead to various forms of n :m mode-locked states, in which a neuron fires n action potentials per m cycles of the stimulus. Here, we study mode-locking in the Izhikevich neurons, a reduced model of the Hodgkin-Huxley neurons. The Izhikevich model is much simpler in terms of the dimension of the coupled nonlinear differential equations compared with other existing models, but excellent for generating the complex spiking patterns observed in real neurons. We obtained the regions of existence of the various mode-locked states on the frequency-amplitude plane, called Arnold tongues, for the Izhikevich neurons. Arnold tongue analysis provides useful insight into the organization of mode-locking behavior of neurons under periodic forcing. We find these tongues for both class-1 and class-2 excitable neurons in both deterministic and noisy regimes.

  8. [New ultrasound navigational system in extracorporeal lithotripsy: decreased fluoroscopy and radiation].

    PubMed

    Abid, N; Ravier, E; Codas, R; Crouzet, S; Martin, X

    2013-09-01

    Extracorporeal shock wave lithotripsy is the most common method of treatment for kidney stones. Both fluoroscopy and ultrasound imaging can be used to locate stones, but fluoroscopy is more frequently employed. Evaluation of a new stereotaxic navigational system: the stone was located using an ultrasound probe, and its 3D location was saved. The table automatically moved to position the stone at the focal point. A real-time follow-up was possible during treatment. Our objective was to demonstrate a decrease in the use of fluoroscopy to locate kidney stones for extracorporeal shock wave lithotripsy through the use of a 3D ultrasound stone locking system. Prospective analysis of the case records of the 20 patients preceding and the 20 patients succeeding the arrival of the ultrasound stone locking system Visio-Track (EDAP-TMS). We used a Student test to compare age, BMI, kidney stone size, number of shock waves and administered energy. Patient characteristics were comparable. The average age was 55 years old and the average kidney stone size was 10.7 mm. Radiation duration was 174.8 seconds in the group without Visio-Track versus 57.1 seconds in the group with it (P<0.0001). A similar result was observed for radiation doses: 5197.25 mGy x cm2 for the group without versus 1987.6 mGy x cm2 for the group with Visio-Track (P=0.0033). The stone locking system Visio-Track reduced fluoroscopy in our first group of patients, which decreased the patient's individual absorbed irradiation dose. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. River enhancement in the Upper Mississippi River basin: Approaches based on river uses, alterations, and management agencies

    USGS Publications Warehouse

    O'Donnell, T. K.; Galat, D.L.

    2007-01-01

    The Upper Mississippi River is characterized by a series of locks and dams, shallow impoundments, and thousands of river channelization structures that facilitate commercial navigation between Minneapolis, Minnesota, and Cairo, Illinois. Agriculture and urban development over the past 200 years have degraded water quality and increased the rate of sediment and nutrient delivery to surface waters. River enhancement has become an important management tool employed to address causes and effects of surface water degradation and river modification in the Upper Mississippi River Basin. We report information on individual river enhancement projects and contrast project densities, goals, activities, monitoring, and cost between commercially non-navigated and navigated rivers (Non-navigated and Navigated Rivers, respectively). The total number of river enhancement projects collected during this effort was 62,108. Cost of all projects reporting spending between 1972 and 2006 was about US$1.6 billion. Water quality management was the most cited project goal within the basin. Other important goals in Navigated Rivers included in-stream habitat improvement and flow modification. Most projects collected for Non-navigated Rivers and their watersheds originated from the U.S. Department of Agriculture (USDA). The U.S. Army Corps of Engineers and the USDA were important sources for projects in Navigated Rivers. Collaborative efforts between agencies that implement projects in Non-navigated and Navigated Rivers may be needed to more effectively address river impairment. However, the current state of data sources tracking river enhancement projects deters efficient and broad-scale integration. ?? Journal compilation ?? 2007 Society for Ecological Restoration International.

  10. 78 FR 34083 - Proposed Reductions in Levels of Service at Locks and Dams on the J Bennett Johnston Waterway...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Proposed Reductions in Levels of... Marine Transportation System Level of Service Guidelines led to the reduced hours of operation for Lock 3... matches existing lock usage. Pool levels will not be affected by change of operating hours. DATES...

  11. Electronic locking system

    NASA Astrophysics Data System (ADS)

    Nieuwkoop, E.

    An electronic locking system was developed to remove the disadvantages of conventional mechanical door locks. The electrolock has to replace existing locks. Therefore, the techniques of Surface Mount Technology and Application Specific Integrated Circuit were applied to overcome the space limitations. The key consists of a metal rod with grip equipped with a contactless chip. When the key is inserted in the lock, a magnetic field is generated in the cylinder which induces a voltage in the chip. Therefore a battery is not required. The chip then emits inductively a code which is unique for each key. The electrolock was successfully tested.

  12. 78 FR 28827 - Notice of Application Accepted for Filing and Soliciting Motions To Intervene and Protests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... bank of the canal; (4) two turbine-generator units providing a combined installed capacity of 2 MW; (5... powerhouse located on the bank of the Muskingum River opposite the existing lock; (3) two turbine-generator... opposite the existing lock; (3) two turbine-generator units providing a combined installed capacity of 4 MW...

  13. 33 CFR 159.12 - Regulations for certification of existing devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Regulations for certification of existing devices. 159.12 Section 159.12 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Certification Procedures § 159.12 Regulations for...

  14. Binary processing and display concepts for low-cost Omega receivers. [airborne systems simulation

    NASA Technical Reports Server (NTRS)

    Lilley, R. W.

    1974-01-01

    A description is given of concepts related to plans for developing a low-cost, all-digital Omega receiver capable of offering to the small-aircraft pilot a reliable and accurate navigation aid. The receiver base considered includes a receiver front-end module, a receiver control module, a memory-aided phase-locked loop module, a housekeeping timer module, and a synthesizer module.

  15. Initial flight test of a Loran-C receiver/data collection system

    NASA Technical Reports Server (NTRS)

    Fischer, J. P.; Nickum, J. D.

    1978-01-01

    Development of a low cost Loran C receiver for general aviation use is discussed. The preparation and procedure of a flight test conducted with a receiver design which utilizes a phase locked loop oscillator to track the Loran C signals is described. It is indicated that such a receiver is a viable alternative for future work in developing a low cost Loran-C navigator.

  16. Field Experience with Lock Culvert Valves

    DTIC Science & Technology

    2013-12-01

    factors pertaining to valves such as the hoist loads, cavitation parameter, and effects of venting. To reduce the surge in the navigation channel...2 min 15 sec, filling-and-emptying valve opening time) ensures that adequate air is drawn into the culvert to cushion the cavitation implosions...shape can have adverse hydrodynamic loading consequences. The USACE, Mobile District (SAM) is in the process of designing replacement valves that are

  17. 46 CFR 95.15-50 - Lockout valves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the event of equipment failure during maintenance. (c) The lockout valve design or locking mechanism..., when the valve must be locked in the closed position. (f) Lockout valves added to existing systems must...

  18. Mode-Locking Behavior of Izhikevich Neuron Under Periodic External Forcing

    NASA Astrophysics Data System (ADS)

    Farokhniaee, Amirali; Large, Edward

    2015-03-01

    In this study we obtained the regions of existence of various mode-locked states on the periodic-strength plane, which are called Arnold Tongues, for Izhikevich neurons. The study is based on the new model for neurons by Izhikevich (2003) which is the normal form of Hodgkin-Huxley neuron. This model is much simpler in terms of the dimension of the coupled non-linear differential equations compared to other existing models, but excellent for generating the complex spiking patterns observed in real neurons. Many neurons in the auditory system of the brain must encode amplitude variations of a periodic signal. These neurons under periodic stimulation display rich dynamical states including mode-locking and chaotic responses. Periodic stimuli such as sinusoidal waves and amplitude modulated (AM) sounds can lead to various forms of n : m mode-locked states, similar to mode-locking phenomenon in a LASER resonance cavity. Obtaining Arnold tongues provides useful insight into the organization of mode-locking behavior of neurons under periodic forcing. Hence we can describe the construction of harmonic and sub-harmonic responses in the early processing stages of the auditory system, such as the auditory nerve and cochlear nucleus.

  19. 5. Looking west upstream, towards the location of the erstwhile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Looking west upstream, towards the location of the erstwhile intake flume into canal from the upper reaches of the Potomac River above the Great Falls, on the old Potowmack Canal built by George Washington. The plan contemplated canal navigation around the Great Falls of the Potomac River, located on the Virginia side of the Potomac, about 15 miles above Washington, D.C. The Company was organized in 1785, and by 1802, this and three or four smaller canals were substantially completed and raft-like boats began operation with materials from the west to the city of Georgetown. 'Although the canals and locks of the Potomac Canal were considered a great engineering accomplishment, the improvements to the river channel were inadequate. Disappointment ... - Potowmack Company: Great Falls Canal & Locks, Great Falls, Fairfax County, VA

  20. 33 CFR 385.36 - Elimination or transfer of existing legal sources of water.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Elimination or transfer of existing legal sources of water. 385.36 Section 385.36 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE PROGRAMMATIC REGULATIONS FOR THE COMPREHENSIVE EVERGLADES RESTORATION PLAN Ensuring Protection of the...

  1. 33 CFR 385.36 - Elimination or transfer of existing legal sources of water.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Elimination or transfer of existing legal sources of water. 385.36 Section 385.36 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE PROGRAMMATIC REGULATIONS FOR THE COMPREHENSIVE EVERGLADES RESTORATION PLAN Ensuring Protection of the...

  2. Broadband features of passively harmonic mode locking in dispersion-managed erbium-doped all-fiber lasers

    NASA Astrophysics Data System (ADS)

    Geng, Y.; Li, L.; Shu, C. J.; Wang, Y. F.; Tang, D. Y.; Zhao, L. M.

    2018-06-01

    Broadband features of passively harmonic mode locking (HML) in dispersion-managed erbium-doped all-fiber lasers are explored. The bandwidth of HML state is generally narrower than that of fundamental mode locking before pulse breaking occurs. There exists a broadest bandwidth versus the order of HML. HML state with bandwidth up to 61.5 nm is obtained.

  3. Freshwater mussel shells (Unionidae) chronicle changes in a North American river over the past 1000 years

    Treesearch

    Andrea K. Fritts; Mark W. Fritts; Wendell R. Haag; Jason A. DeBoer; Andrew F. Casper

    2017-01-01

    The Illinois River was substantially altered during the 20th century with the installation of navigational locks and dams, construction of extensive levee networks, and degradation of water quality. Freshwater mussels were affected by these changes.Weused sclerochronology and stable isotopes to evaluate changes over time in age-andgrowth and food sources for two mussel...

  4. Phase-locked patterns of the Kuramoto model on 3-regular graphs

    NASA Astrophysics Data System (ADS)

    DeVille, Lee; Ermentrout, Bard

    2016-09-01

    We consider the existence of non-synchronized fixed points to the Kuramoto model defined on sparse networks: specifically, networks where each vertex has degree exactly three. We show that "most" such networks support multiple attracting phase-locked solutions that are not synchronized and study the depth and width of the basins of attraction of these phase-locked solutions. We also show that it is common in "large enough" graphs to find phase-locked solutions where one or more of the links have angle difference greater than π/2.

  5. Phase-locked patterns of the Kuramoto model on 3-regular graphs.

    PubMed

    DeVille, Lee; Ermentrout, Bard

    2016-09-01

    We consider the existence of non-synchronized fixed points to the Kuramoto model defined on sparse networks: specifically, networks where each vertex has degree exactly three. We show that "most" such networks support multiple attracting phase-locked solutions that are not synchronized and study the depth and width of the basins of attraction of these phase-locked solutions. We also show that it is common in "large enough" graphs to find phase-locked solutions where one or more of the links have angle difference greater than π/2.

  6. Scalar-vector soliton fiber laser mode-locked by nonlinear polarization rotation.

    PubMed

    Wu, Zhichao; Liu, Deming; Fu, Songnian; Li, Lei; Tang, Ming; Zhao, Luming

    2016-08-08

    We report a passively mode-locked fiber laser by nonlinear polarization rotation (NPR), where both vector and scalar soliton can co-exist within the laser cavity. The mode-locked pulse evolves as a vector soliton in the strong birefringent segment and is transformed into a regular scalar soliton after the polarizer within the laser cavity. The existence of solutions in a polarization-dependent cavity comprising a periodic combination of two distinct nonlinear waves is first demonstrated and likely to be applicable to various other nonlinear systems. For very large local birefringence, our laser approaches the operation regime of vector soliton lasers, while it approaches scalar soliton fiber lasers under the condition of very small birefringence.

  7. Using phase locking for improving frequency stability and tunability of THz-band gyrotrons

    NASA Astrophysics Data System (ADS)

    Adilova, Asel B.; Gerasimova, Svetlana A.; Melnikova, Maria M.; Tyshkun, Alexandra V.; Rozhnev, Andrey G.; Ryskin, Nikita M.

    2018-04-01

    Medium-power (10-100 W) THz-band gyrotrons operating in a continuous-wave (CW) mode are of great importance for many applications such as NMR spectroscopy with dynamic nuclear polarization (DNP/NMR), plasma diagnostics, nondestructive inspection, stand-off detection of radioactive materials, biomedical applications, etc. For all these applications, high frequency stability and tunability within 1-2 GHz frequency range is typically required. Apart from different existing techniques for frequency stabilization, phase locking has recently attracted strong interest. In this paper, we present the results of theoretical analysis and numerical simulation for several phase locking techniques: (a) phase locking by injection of the external driving signal; (b) mutual phase locking of two coupled gyrotrons; and (c) selfinjection locking by a wave reflected from the remote load.

  8. Optical Injection Locking of a VCSEL in an OEO

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute

    2009-01-01

    Optical injection locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface- emitting laser (VCSEL) that is an active element in the frequency-control loop of an opto-electronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency resonance. This particular optical-injection- locking scheme is expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. Inasmuch as the microwave power circulating in the frequency-control loop is a dynamic frequency-control variable (and, hence, cannot be stabilized), there arises a need for another means of stabilizing the wavelength. The present optical-injection-locking scheme satisfies the need for a means to stabilize the wavelength against microwave- power fluctuations. It is also expected to afford stabilization against temperature and current fluctuations. In an experiment performed to demonstrate this scheme, wavelength locking was observed when about 200 W of the output power of a commercial tunable diode laser was injected into a commercial VCSEL, designed to operate in the wavelength range of 795+/-3 nm, that was generating about 200 microW of optical power. (The use of relatively high injection power levels is a usual practice in injection locking of VCSELs.)

  9. External Tank (ET) Bipod Fitting Bolted Attachment Locking Insert Performance

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis E.; Wilson, Tim R.; Elliott, Kenny B.; Raju, Ivatury S.; McManamen, John

    2008-01-01

    Following STS-107, the External Tank (ET) Project implemented corrective actions and configuration changes at the ET bipod fitting. Among the corrective actions, the existing bolt lock wire which provided resistance to potential bolt rotation was removed. The lock wire removal was because of concerns with creating voids during foam application and potential for lock wire to become debris. The bolts had been previously lubricated to facilitate assembly but, because of elimination of the lock wire, the ET Project wanted to enable the locking feature of the insert. Thus, the lubrication was removed from bolt threads and instead applied to the washer under the bolt head. Lubrication is necessary to maximize joint pre-load while remaining within the bolt torque specification. The locking feature is implemented by thread crimping in at four places in the insert. As the bolt is torqued into the insert the bolt threads its way past the crimped parts of the insert. This provides the locking of the bolt, as torque is required to loosen the joint after clamping.

  10. 75 FR 47808 - Alabama Municipal Electric Authority; Notice of Competing Preliminary Permit Application Accepted...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ..., proposing to study the feasibility of the George W. Andrews Lock and Dam Hydroelectric Project. The proposed project would be located at the existing George W. Andrews Lock and Dam on the Chattahoochee River in...

  11. Shuttle GPS R/PA evaluation analysis and performance tradeoff study

    NASA Technical Reports Server (NTRS)

    Booth, R. W. D.; Lindsey, W. C.

    1978-01-01

    Primary responsibility was understanding and analyzing the various GPS receiver functions as they relate to the shuttle environment. These receiver functions included acquisition properties of the sequential detector, acquisition and tracking properties of the various receiver phase locked loops, and the techniques of sequential receiver operation. In addition to these areas, support was provided in the areas of oscillator stability requirements, antenna management, and navigation filter requirements, including preposition aiding.

  12. Improving Estimates Of Phase Parameters When Amplitude Fluctuates

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V. A.; Brown, D. H.; Hurd, W. J.

    1989-01-01

    Adaptive inverse filter applied to incoming signal and noise. Time-varying inverse-filtering technique developed to improve digital estimate of phase of received carrier signal. Intended for use where received signal fluctuates in amplitude as well as in phase and signal tracked by digital phase-locked loop that keeps its phase error much smaller than 1 radian. Useful in navigation systems, reception of time- and frequency-standard signals, and possibly spread-spectrum communication systems.

  13. St. Lawrence Seaway N.Y. Feasibility Study for Additional Locks and Other Navigation Improvements: Plan of Study. Revision.

    DTIC Science & Technology

    1979-11-01

    Ashland, WI Lake Huron Lake Michigan Ontonagon, MI Presque Isle, MI : Alpena , MI Oak Creek, WI Marquette, MI Cheboygan, MI Buffington, IN Keweenaw Waterway...State of Michigan include Calcite, Stoneport, Alpena , Alabasier, Bay City, Saginaw, and Port Huron. Other large harbors on Lake Michigan are Port...Joseph Alpena : Auglaize Tompkins Steuben : Arenac Crawford Wayne Bay Cayuga Wyoming Cheboygan Defiance Yates Clare Erie Crawford : Fulton Source

  14. 11. photographer unknown 3 September 1984 AERIAL VIEW OF BONNEVILLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. photographer unknown 3 September 1984 AERIAL VIEW OF BONNEVILLE PROJECT TAKEN AT 6000-FOOT ELEVATION. POWERHOUSE #1 AND NAVIGATION LOCK ARE IN UPPER/CENTER PART OF PHOTO, AND THE DAM/SPILLWAY IS IN LEFT/CENTER; THE SECOND POWERHOUSE IS PARTIALLY VISIBLE IN LOWER LEFT CORNER. COLUMBIA RIVER FLOWS FROM LEFT-TO-RIGHT. - Bonneville Project, Columbia River, 1 mile Northeast of Exit 40, off Interstate 84, Bonneville, Multnomah County, OR

  15. Repair, Evaluation, Maintenance, and Rehabilitation Research Program. Rehabilitation of Navigation Lock Walls: Case Histories.

    DTIC Science & Technology

    1987-12-01

    the 50-year design ser- vice life. Since these structures were built prior to 1940, the concrete does not contain intentionally entrained air and is...with which designers and contractors are familiar from past experience on new construction. However, there is increasing evidence that rehabilitation...with designers and contractors. Although the Information obtained from the various sources varied widely from project to project, attempts were made to

  16. 33 CFR 62.63 - Recommendations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Recommendations. 62.63 Section 62... Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the discontinuation of existing aids, and report aids no longer necessary for maritime safety. These recommendations...

  17. 33 CFR 62.63 - Recommendations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....63 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

  18. 33 CFR 62.63 - Recommendations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....63 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

  19. Analysis of Multi-Antenna GNSS Receiver Performance under Jamming Attacks.

    PubMed

    Vagle, Niranjana; Broumandan, Ali; Lachapelle, Gérard

    2016-11-17

    Although antenna array-based Global Navigation Satellite System (GNSS) receivers can be used to mitigate both narrowband and wideband electronic interference sources, measurement distortions induced by array processing methods are not suitable for high precision applications. The measurement distortions have an adverse effect on the carrier phase ambiguity resolution, affecting the navigation solution. Depending on the array attitude information availability and calibration parameters, different spatial processing methods can be implemented although they distort carrier phase measurements in some cases. This paper provides a detailed investigation of the effect of different array processing techniques on array-based GNSS receiver measurements and navigation performance. The main novelty of the paper is to provide a thorough analysis of array-based GNSS receivers employing different beamforming techniques from tracking to navigation solution. Two beamforming techniques, namely Power Minimization (PM) and Minimum Power Distortionless Response (MPDR), are being investigated. In the tracking domain, the carrier Doppler, Phase Lock Indicator (PLI), and Carrier-to-Noise Ratio (C/N₀) are analyzed. Pseudorange and carrier phase measurement distortions and carrier phase position performance are also evaluated. Performance analyses results from simulated GNSS signals and field tests are provided.

  20. Beacons for supporting lunar landing navigation

    NASA Astrophysics Data System (ADS)

    Theil, Stephan; Bora, Leonardo

    2017-03-01

    Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.

  1. Influence of beam-loaded effects on phase-locking in the high power microwave oscillator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Zhenghong; Zhou, Zhigang; Qiu, Rong

    2014-06-15

    Owing to the power limitation of a single device, much more attentions are focused on developing high power microwave (HPM) oscillators that can be phase-locked to the external signal in the recent HPM researches. Although the phase-locking is proved to be feasible in the conventional devices (such as magnetrons), challenges still exist in the HPM devices due to beam-loaded effects, which are more obvious in HPM devices because of its high current and the low Q-factor of the device. A simple structured HPM oscillator (Bitron) is introduced to study such effects on the phase-locking in the HPM oscillator. The self-consistentmore » analysis is carried out to study such effects together with particle in cell simulations. Then the modified Adler equation is established for the phase-locking HPM oscillator. Finally, conditions for the phase-locking in the HPM oscillator are given.« less

  2. A Ferris Wheel Accident at a Movable Amusement Park.

    PubMed

    Cho, Young-Jin; Ji, Hong-Keun; Moon, Byung-Sun; Park, Ha-Sun; Goh, Jae-Mo; Park, Nam-Kyu; Choi, Don-Mook

    2017-05-01

    This study presented a Ferris wheel accident case. A Ferris wheel is composed of many parts, and the outmost ring of it is assembled using a lock pin. This accident occurred because the lock pin caught the door of a gondola and the gondola overturned. Five of the seven passengers in the gondola fell to the ground, along with the gondola's viewing window. The investigation revealed that the gondola became stuck when its door was caught by a lock pin at the Ferris wheel's three o'clock position. The contact between the door and the lock pin was due to a structural problem: There was not enough space allotted between the door and the lock pin. Therefore, if a passenger pushed on the gondola's door, the potential existed for contact between the door and the lock pin. © 2016 American Academy of Forensic Sciences.

  3. Advances in Inertial Navigation Systems and Components

    DTIC Science & Technology

    1981-04-01

    directions: a. Improvement of the classical fringeshil’t reading through differential two- detector schemes and application of very low loss components...1969 29. Aronowitz, F., " Loss Lock-In in Ringlaser," J. Appi Physics 41, 130 (1970) 30. Malota, F , "Ringlaser and Ringinterferometer," Laser and...8217 . ] 4-9 TABLE I Iý0PPERHEAD RRS CHARACTERISTICS SUMMARY Weight of Jet: - 3.8 oz. Weight of Total Packagt: - 12.0 oz. Volume of Total Packagi?: - 10.5 in

  4. Effects of temperature and aerial exposure on the BOD of waste zebra mussels removed from navigational locks.

    PubMed

    Aldridge, D W; Payne, B S

    2001-08-01

    This laboratory study evaluated the effects of temperature and aerial exposure on BOD5 (5-day BOD) of waste zebra mussels of the type generated by maintenance operations on dams and navigational locks. The term waste zebra mussels includes the mussels and their associated debris with the latter including sediment, feces, pseudofeces and other small aquatic organisms. The BOD5 of waste zebra mussel was evaluated after aerial exposure of 3 and 10 days at temperatures of 5, 10, and 20 degrees C. The mean BOD5 values for waste zebra mussels in this study ranged from 18,500 to 30,600 mg O2/l. Factorial ANOVA analysis revealed that both temperature and aerial exposure had a negative effect on waste zebra mussel BOD5 (P<0.05) but there was no significant interaction effect (P = 0.119). Multiple regression analysis predicted that for the range of treatment conditions used in this study each 1 degrees C increase in temperature reduced the waste zebra mussel BOD5 by 284mg O2/l or 0.93% of the maximum mean BOD5. Each I day increase in aerial exposure reduced waste zebra mussel BOD5 by 987 mg O2/l or 3.22% of the maximum mean BOD5. Aerial exposure of waste zebra mussels substantially reduces waste BOD5.

  5. A study on multifrequency scintillations near the EIA crest of the Indian zone

    NASA Astrophysics Data System (ADS)

    Chakraborty, S. K.; Chatterjee, S.; Jana, Debasis

    2017-10-01

    Occurrence features of ionospheric scintillations at S band (2492.028 MHz) are reported for the first time. The same have been explored in the context of scintillations at VHF (250.650 MHz) and L5 (1176.45 MHz) bands. Observations were carried out during the period April-December, 2015 at Raja Peary Mohan College Centre (RPMC: 22.66° N, 88.4° E), located near the equatorial ionization anomaly (EIA) crest of the Indian longitude zone. Mostly weak (<10 dB), short duration, slow fading rate with shallower slope power spectra characterize the S band scintillations compared to VHF and L5 band. In the severe scintillation conditions of VHF frequent loss of lock in L5 channel is reflected. Fade depth of 4.2 ± 1.3 dB and fade rate ∼9 fades/minute at S band mostly precede the loss of lock at L5 channel. A good correspondence between fade rates at multi frequency band is reflected irrespective of phases of scintillation. Spectral analysis reveals weak scattering is the dominating mechanism for scintillation at S band while VHF and L5 band scintillations are mostly attributed to multiple scattering. The estimated threshold coherence length of <23 m at VHF may be suggested to be a good indicator for occurrence of L5 and S band scintillations. Occurrence of simultaneous multi-satellite multi-frequency scintillations leads to speculation over the failsafe navigation using available IRNSS constellation. The results are discussed in terms of existing theory of evolution, structure and dynamics of electron density irregularities in the low latitude region.

  6. Experimental investigation of different regimes of mode-locking in a high repetition rate passively mode-locked semiconductor quantum-dot laser.

    PubMed

    Kéfélian, Fabien; O'Donoghue, Shane; Todaro, Maria Teresa; McInerney, John; Huyet, Guillaume

    2009-04-13

    We report experimental investigations on a two-section 16-GHz repetition rate InAs/GaAs quantum dot passively mode-locked laser. Near the threshold current, pseudo-periodic Q-switching with complex dynamics is exhibited. Mode-locking operation regimes characterized by different repetition rates and timing jitter levels are encountered up to twice the threshold current. Evolution of the RF spectrum and optical spectrum with current is compared. The different mode-locked regimes are shown to be associated with different spectral and temporal shapes, ranging from 1.3 to 6 ps. This point is discussed by introducing the existence of two different supermodes. Repetition rate evolution and timing jitter increase is attributed to the coupling between the dominant and the secondary supermodes.

  7. Method, accuracy and limitation of computer interaction in the operating room by a navigated surgical instrument.

    PubMed

    Hurka, Florian; Wenger, Thomas; Heininger, Sebastian; Lueth, Tim C

    2011-01-01

    This article describes a new interaction device for surgical navigation systems--the so-called navigation mouse system. The idea is to use a tracked instrument of a surgical navigation system like a pointer to control the software. The new interaction system extends existing navigation systems with a microcontroller-unit. The microcontroller-unit uses the existing communication line to extract the needed 3D-information of an instrument to calculate positions analogous to the PC mouse cursor and click events. These positions and events are used to manipulate the navigation system. In an experimental setup the reachable accuracy with the new mouse system is shown.

  8. Self-locking degree-4 vertex origami structures

    PubMed Central

    Li, Suyi; Wang, K. W.

    2016-01-01

    A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications. PMID:27956889

  9. Self-locking degree-4 vertex origami structures.

    PubMed

    Fang, Hongbin; Li, Suyi; Wang, K W

    2016-11-01

    A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.

  10. Qualitative Evaluation of a New Tobacco Cessation Training Curriculum for Patient Navigators

    PubMed Central

    Shuk, Elyse; Krebs, Paul; Lu, Wei-Hsin; Burkhalter, Jack; Cortez-Weir, Jeralyn; Rodriguez, Rian; Burnside, Vanessa N.; Lubetkin, Erica I.

    2011-01-01

    Treatments for tobacco dependence exist but are underutilized, particularly among low-income and minority smokers. Patient navigation has been shown to help patients overcome barriers to quality care. In preparation for testing the feasibility of integrating tobacco cessation patient navigation into primary care, this paper describes the development and qualitative evaluation of a new curriculum for training patient navigators to address cessation treatment barriers faced by low-income, minority smokers who are advised to quit by their physicians. Thematic text analysis of transcripts obtained from focus groups with experienced patient navigators (n = 19) was conducted. Participants endorsed patient navigation as a relevant strategy for addressing tobacco cessation treatment barriers and made several recommendations regarding the knowledge, core competencies, and skills needed to conduct tobacco cessation patient navigation. This curriculum could be used by existing patient navigation training centers or made available as a self-guided continuing education program for experienced navigators who wish to expand their navigation interventions to include a tobacco cessation focus. PMID:21553331

  11. 33 CFR 245.20 - Determination of hazard to navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... weather conditions. (9) Length of time the obstruction has been in existence. (10) History of vessel...

  12. 33 CFR 245.20 - Determination of hazard to navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... weather conditions. (9) Length of time the obstruction has been in existence. (10) History of vessel...

  13. 33 CFR 245.20 - Determination of hazard to navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... weather conditions. (9) Length of time the obstruction has been in existence. (10) History of vessel...

  14. 33 CFR 245.20 - Determination of hazard to navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... weather conditions. (9) Length of time the obstruction has been in existence. (10) History of vessel...

  15. 33 CFR 245.20 - Determination of hazard to navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... weather conditions. (9) Length of time the obstruction has been in existence. (10) History of vessel...

  16. 33 CFR 62.63 - Recommendations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Recommendations. 62.63 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

  17. 43 CFR 2651.6 - Airport and air navigation facilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Airport and air navigation facilities... Village Selections § 2651.6 Airport and air navigation facilities. (a) Every airport and air navigation.... (b) The surface of all other lands of existing airport sites, airway beacons, or other navigation...

  18. 43 CFR 2651.6 - Airport and air navigation facilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Airport and air navigation facilities... Village Selections § 2651.6 Airport and air navigation facilities. (a) Every airport and air navigation.... (b) The surface of all other lands of existing airport sites, airway beacons, or other navigation...

  19. 43 CFR 2651.6 - Airport and air navigation facilities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Airport and air navigation facilities... Village Selections § 2651.6 Airport and air navigation facilities. (a) Every airport and air navigation.... (b) The surface of all other lands of existing airport sites, airway beacons, or other navigation...

  20. Kentucky River and Tributaries. Upper Kentucky River Navigation Project. Volume 2. Public Involvement Record.

    DTIC Science & Technology

    1980-11-01

    after this terrible terrific financial error. I’m also hoping that the Division Office in Cincinnati has n.jt been hoodwinked by the District Office. I...know that our representatives in the Senate and the House in Washington, will not, and I repeat, will not, stand for any shenanigans to the people in...cannot be done. The closing of these locks will place an inequitable financial burden on pleasure boat owners. This hardship is even more pronounced

  1. The Differential Vector Phase-Locked Loop for Global Navigation Satellite System Signal Tracking

    DTIC Science & Technology

    2014-06-01

    DAF Approved: //signed// John F. Raquet, PhD (Chairman) //signed// Mark E. Oxley, PhD (Member) //signed// Maj Marshall E. Haker , PhD (Member) 16 May...busy as you keep yourself. Dr. Mark Oxley and Dr. Marshall Haker for your sage guidance as members of my committee. Dr. Ken Fisher for making Kalman...Raquet, Dr. Marshall Haker , and Mr. Ben Downing at AFIT, following notes for Dr. Raquet’s Advanced GPS Receiver Design class. The second type was RINEX

  2. Contextual Essays on the Monongahela River Navigation System. Locks and Dams 2, 3 and 4 Monongahela River Project

    DTIC Science & Technology

    2012-09-24

    1966. One of the Agreement’s stipulations says "In order to provide a historic context for the evaluation of historic properties identified within...divided North from South literally and figuratively, even as it connected East and West literally and figuratively (Wood 1996: 119). Peirce Lewis says ...some historians have pointed out its obvious successes. Ronald Shaw, in his book on American canals before the Civil War, says that "traffic was

  3. Hydraulic Design of Navigation Locks

    DTIC Science & Technology

    1989-09-01

    service brought about by surface deposits, erossion, corrosion , bacterial slimes and growths and marine and fresh water fouling. Experience of similar...Drawn brass, copper, alluminium , etc. 0.0025 Glass, plastic, perspex, fibre glass, etc. 0.0025 2. Steel pipes New smooth pipes 0.025 Centrifugally...1 H l I T j I 1 1 In E 1- 0 C D I ) N N C4dv Fig. .1. oodyChar TBT7 2. Adequate initial protection to prevent corrosion and erosion. 3. Chlorination

  4. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Lock), shall open on signal; except that, from 6:30 a.m. to 8:30 a.m. and from 3:30 p.m. to 5:45 p.m....m. to 8:30 a.m. and 5 p.m. to 6:30 p.m. Monday through Friday. (c) The draw of the Senator Ted....; except that the bridge need not open from 7 a.m. to 8:30 a.m. and 5 p.m. to 6:30 p.m. Monday through...

  5. Annual Report of the Chief of Engineers, U.S. Army, on Civil Works Activities 1961. Volume 1

    DTIC Science & Technology

    1961-01-01

    dollars) Classification Total Active De - Ink Total Active De - In- ferred active ferred active Navigation..------------------ 2,604 2,450 42 112 6,138...Sioux City, Iowa.... New York and New Jersey Channels, N.Y. and N.J.. Pike Island Locks and Dam, Ohio River, W. Va..... Playa Del Rey Inlet and Harbor...Jun 61 -1965 Do. Hall Meadow Brook, Conn __ . ___------- - Oct 60 1962 Reservoir. Hunt and Lima Lake Drainage District, Illinois

  6. Entropy driven key-lock assembly.

    PubMed

    Odriozola, G; Jiménez-Angeles, F; Lozada-Cassou, M

    2008-09-21

    The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a two-dimensional map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: There exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assemblydisassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.

  7. Entropy driven key-lock assembly

    NASA Astrophysics Data System (ADS)

    Odriozola, G.; Jiménez-Ángeles, F.; Lozada-Cassou, M.

    2008-09-01

    The effective interaction between a sphere with an open cavity (lock) and a spherical macroparticle (key), both immersed in a hard sphere fluid, is studied by means of Monte Carlo simulations. As a result, a two-dimensional map of the key-lock effective interaction potential is constructed, which leads to the proposal of a self-assembling mechanism: There exists trajectories through which the key-lock pair could assemble avoiding trespassing potential barriers. Hence, solely the entropic contribution can induce their self-assembling even in the absence of attractive forces. This study points out the solvent contribution within the underlying mechanisms of substrate-protein assembly/disassembly processes, which are important steps of the enzyme catalysis and protein mediated transport.

  8. 78 FR 62359 - Red River Hydro LLC; Notice of Availability of Final Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-21

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13160-004] Red River Hydro... Projects has reviewed Red River Hydro LLC's application for an original license for the Overton Lock and... (EA). The project would be located on the Red River in Rapides Parish, Louisiana, at an existing lock...

  9. 75 FR 6020 - Notice of Competing Preliminary Permit Applications Accepted for Filing and Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-05

    ... feasibility of the George W. Andrews Hydroelectric Project located at the existing George W. Andrews Lock and.... Andrews Lock and Dam Hydroelectric Project by Brookfield Power (Project No. 13077-000, filed on November... have an average annual generation of 89 gigawatt-hours. The proposed George W. Andrews Hydroelectric...

  10. A New Perspective on Job Lock

    ERIC Educational Resources Information Center

    Huysse-Gaytandjieva, Anna; Groot, Wim; Pavlova, Milena

    2013-01-01

    This paper analyses the situation when employees fail to adapt to overall job dissatisfaction. By combining the existing knowledge in economics on job lock and in psychology on employees' feeling of being "stuck" at work, the paper explains why some employees fail to adapt when dissatisfied with their job. Thus, the paper aims to expand…

  11. Results of the second flight test of the Loran-C receiver/data collection system

    NASA Technical Reports Server (NTRS)

    Fischer, J. P.

    1979-01-01

    The components of the Loran-C navigation system which were developed thus far are a phase-locked-loop receiver and a microcomputer development system. The microcomputer is being used as a means of testing and implementing software to handle sensor control and navigation calculations. Currently, the microcomputer is being used to collect and record data from the receiver in addition to development work. With these components, it was possible to record receiver data over a period of time and then reduce this data to obtain statistical information. It was particularly interesting to load the equipment developed in the laboratory into an aircraft and collect data while in flight. For initial flight tests, some important considerations were how well the entire system will perform in the field, signal strength levels while on the ground and in the air, the amount of noise present, changing of signal-to-noise ratio for various aircraft configurations and maneuvers, receiver overloading due to other equipment and antennas, and the overall usefulness of Loran-C as a navigation aid.

  12. Inertial Navigation System/Doppler Velocity Log (INS/DVL) Fusion with Partial DVL Measurements

    PubMed Central

    Tal, Asaf; Klein, Itzik; Katz, Reuven

    2017-01-01

    The Technion autonomous underwater vehicle (TAUV) is an ongoing project aiming to develop and produce a small AUV to carry on research missions, including payload dropping, and to demonstrate acoustic communication. Its navigation system is based on an inertial navigation system (INS) aided by a Doppler velocity log (DVL), magnetometer, and pressure sensor (PS). In many INSs, such as the one used in TAUV, only the velocity vector (provided by the DVL) can be used for aiding the INS, i.e., enabling only a loosely coupled integration approach. In cases of partial DVL measurements, such as failure to maintain bottom lock, the DVL cannot estimate the vehicle velocity. Thus, in partial DVL situations no velocity data can be integrated into the TAUV INS, and as a result its navigation solution will drift in time. To circumvent that problem, we propose a DVL-based vehicle velocity solution using the measured partial raw data of the DVL and additional information, thereby deriving an extended loosely coupled (ELC) approach. The implementation of the ELC approach requires only software modification. In addition, we present the TAUV six degrees of freedom (6DOF) simulation that includes all functional subsystems. Using this simulation, the proposed approach is evaluated and the benefit of using it is shown. PMID:28241410

  13. Inertial Navigation System/Doppler Velocity Log (INS/DVL) Fusion with Partial DVL Measurements.

    PubMed

    Tal, Asaf; Klein, Itzik; Katz, Reuven

    2017-02-22

    The Technion autonomous underwater vehicle (TAUV) is an ongoing project aiming to develop and produce a small AUV to carry on research missions, including payload dropping, and to demonstrate acoustic communication. Its navigation system is based on an inertial navigation system (INS) aided by a Doppler velocity log (DVL), magnetometer, and pressure sensor (PS). In many INSs, such as the one used in TAUV, only the velocity vector (provided by the DVL) can be used for aiding the INS, i.e., enabling only a loosely coupled integration approach. In cases of partial DVL measurements, such as failure to maintain bottom lock, the DVL cannot estimate the vehicle velocity. Thus, in partial DVL situations no velocity data can be integrated into the TAUV INS, and as a result its navigation solution will drift in time. To circumvent that problem, we propose a DVL-based vehicle velocity solution using the measured partial raw data of the DVL and additional information, thereby deriving an extended loosely coupled (ELC) approach. The implementation of the ELC approach requires only software modification. In addition, we present the TAUV six degrees of freedom (6DOF) simulation that includes all functional subsystems. Using this simulation, the proposed approach is evaluated and the benefit of using it is shown.

  14. Research on the Rapid and Accurate Positioning and Orientation Approach for Land Missile-Launching Vehicle

    PubMed Central

    Li, Kui; Wang, Lei; Lv, Yanhong; Gao, Pengyu; Song, Tianxiao

    2015-01-01

    Getting a land vehicle’s accurate position, azimuth and attitude rapidly is significant for vehicle based weapons’ combat effectiveness. In this paper, a new approach to acquire vehicle’s accurate position and orientation is proposed. It uses biaxial optical detection platform (BODP) to aim at and lock in no less than three pre-set cooperative targets, whose accurate positions are measured beforehand. Then, it calculates the vehicle’s accurate position, azimuth and attitudes by the rough position and orientation provided by vehicle based navigation systems and no less than three couples of azimuth and pitch angles measured by BODP. The proposed approach does not depend on Global Navigation Satellite System (GNSS), thus it is autonomous and difficult to interfere. Meanwhile, it only needs a rough position and orientation as algorithm’s iterative initial value, consequently, it does not have high performance requirement for Inertial Navigation System (INS), odometer and other vehicle based navigation systems, even in high precise applications. This paper described the system’s working procedure, presented theoretical deviation of the algorithm, and then verified its effectiveness through simulation and vehicle experiments. The simulation and experimental results indicate that the proposed approach can achieve positioning and orientation accuracy of 0.2 m and 20″ respectively in less than 3 min. PMID:26492249

  15. Research on the rapid and accurate positioning and orientation approach for land missile-launching vehicle.

    PubMed

    Li, Kui; Wang, Lei; Lv, Yanhong; Gao, Pengyu; Song, Tianxiao

    2015-10-20

    Getting a land vehicle's accurate position, azimuth and attitude rapidly is significant for vehicle based weapons' combat effectiveness. In this paper, a new approach to acquire vehicle's accurate position and orientation is proposed. It uses biaxial optical detection platform (BODP) to aim at and lock in no less than three pre-set cooperative targets, whose accurate positions are measured beforehand. Then, it calculates the vehicle's accurate position, azimuth and attitudes by the rough position and orientation provided by vehicle based navigation systems and no less than three couples of azimuth and pitch angles measured by BODP. The proposed approach does not depend on Global Navigation Satellite System (GNSS), thus it is autonomous and difficult to interfere. Meanwhile, it only needs a rough position and orientation as algorithm's iterative initial value, consequently, it does not have high performance requirement for Inertial Navigation System (INS), odometer and other vehicle based navigation systems, even in high precise applications. This paper described the system's working procedure, presented theoretical deviation of the algorithm, and then verified its effectiveness through simulation and vehicle experiments. The simulation and experimental results indicate that the proposed approach can achieve positioning and orientation accuracy of 0.2 m and 20″ respectively in less than 3 min.

  16. 33 CFR 151.2060 - Reporting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Reporting requirements. 151.2060 Section 151.2060 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... § 151.2060 Reporting requirements. (a) Ballast water reporting requirements exist for each vessel...

  17. 33 CFR 151.2060 - Reporting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Reporting requirements. 151.2060 Section 151.2060 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... § 151.2060 Reporting requirements. (a) Ballast water reporting requirements exist for each vessel...

  18. 33 CFR 151.2060 - Reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Reporting requirements. 151.2060 Section 151.2060 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... § 151.2060 Reporting requirements. (a) Ballast water reporting requirements exist for each vessel...

  19. Location tracking forensics on mobile devices

    NASA Astrophysics Data System (ADS)

    Sack, Stefan; Kröger, Knut; Creutzburg, Reiner

    2013-03-01

    The spread of navigation devices has increased significantly over the last 10 years. With the help of the current development of even smaller navigation receiver units it is to navigate with almost any current smart phone. Modern navigation systems are no longer limited to satellite navigation, but use current techniques, e.g. WLAN localization. Due to the increased use of navigation devices their relevance to forensic investigations has risen rapidly. Because navigation, for example with navigation equipment and smartphones, have become common place these days, also the amount of saved navigation data has risen rapidly. All of these developments lead to a necessary forensic analysis of these devices. However, there are very few current procedures for investigating of navigation devices. Navigation data is forensically interesting because by the position of the devices in most cases the location and the traveled path of the owner can be reconstructed. In this work practices for forensic analysis of navigation devices are developed. Different devices will be analyzed and it is attempted, by means of forensic procedures to restore the traveled path of the mobile device. For analysis of the various devices different software and hardware is used. There will be presented common procedures for securing and testing of mobile devices. Further there will be represented the specials in the investigation of each device. The different classes considered are GPS handhelds, mobile navigation devices and smartphones. It will be attempted, wherever possible, to read all data of the device. The aim is to restore complete histories of the navigation data and to forensically study and analyze these data. This is realized by the usage of current forensic software e.g. TomTology or Oxygen Forensic Suite. It is also attempted to use free software whenever possible. Further alternative methods are used (e.g. rooting) to access locked data of the unit. To limit the practical work the data extraction is focused on the frequently used device sample of a specific class, as the procedure for many groups of devices can be similar. In the present work a Garmin Dakota 10, a TomTom GO 700, an iPhone 4 (iOS) and a Samsung Galaxy S Plus (Android) is used because they have a wide circulation.

  20. Phase-locked telemetry system for rotary instrumentation of turbomachinery, phase 1

    NASA Technical Reports Server (NTRS)

    Adler, A.; Hoeks, B.

    1978-01-01

    A telemetry system for use in making strain and temperature measurements on the rotating components of high speed turbomachines employs phase locked transmitters, which offer greater measurement channel capacity and reliability than existing systems which employ L-C carrier oscillators. A prototype transmitter module was tested at 175 C combined with 40,000 g's acceleration.

  1. 75 FR 62516 - Northern Illinois Hydropower, LLC; Notice of Application Ready for Environmental Analysis and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ...: Northern Illinois Hydropower, LLC. e. Name of Project: Dresden Island Project. f. Location: U.S. Army Corps of Engineers' Dresden Island Lock and Dam on the Illinois River, in the Town of Morris, Grundy County... Description: The Dresden Island Project would utilize the Corps of Engineers' existing Dresden Island Lock and...

  2. Investigation of monolithic passively mode-locked quantum dot lasers with extremely low repetition frequency.

    PubMed

    Xu, Tianhong; Cao, Juncheng; Montrosset, Ivo

    2015-01-01

    The dynamical regimes and performance optimization of quantum dot monolithic passively mode-locked lasers with extremely low repetition rate are investigated using the numerical method. A modified multisection delayed differential equation model is proposed to accomplish simulations of both two-section and three-section passively mode-locked lasers with long cavity. According to the numerical simulations, it is shown that fundamental and harmonic mode-locking regimes can be multistable over a wide current range. These dynamic regimes are studied, and the reasons for their existence are explained. In addition, we demonstrate that fundamental pulses with higher peak power can be achieved when the laser is designed to work in a region with smaller differential gain.

  3. A rhythm-based authentication scheme for smart media devices.

    PubMed

    Lee, Jae Dong; Jeong, Young-Sik; Park, Jong Hyuk

    2014-01-01

    In recent years, ubiquitous computing has been rapidly emerged in our lives and extensive studies have been conducted in a variety of areas related to smart devices, such as tablets, smartphones, smart TVs, smart refrigerators, and smart media devices, as a measure for realizing the ubiquitous computing. In particular, smartphones have significantly evolved from the traditional feature phones. Increasingly higher-end smartphone models that can perform a range of functions are now available. Smart devices have become widely popular since they provide high efficiency and great convenience for not only private daily activities but also business endeavors. Rapid advancements have been achieved in smart device technologies to improve the end users' convenience. Consequently, many people increasingly rely on smart devices to store their valuable and important data. With this increasing dependence, an important aspect that must be addressed is security issues. Leaking of private information or sensitive business data due to loss or theft of smart devices could result in exorbitant damage. To mitigate these security threats, basic embedded locking features are provided in smart devices. However, these locking features are vulnerable. In this paper, an original security-locking scheme using a rhythm-based locking system (RLS) is proposed to overcome the existing security problems of smart devices. RLS is a user-authenticated system that addresses vulnerability issues in the existing locking features and provides secure confidentiality in addition to convenience.

  4. A Rhythm-Based Authentication Scheme for Smart Media Devices

    PubMed Central

    Lee, Jae Dong; Park, Jong Hyuk

    2014-01-01

    In recent years, ubiquitous computing has been rapidly emerged in our lives and extensive studies have been conducted in a variety of areas related to smart devices, such as tablets, smartphones, smart TVs, smart refrigerators, and smart media devices, as a measure for realizing the ubiquitous computing. In particular, smartphones have significantly evolved from the traditional feature phones. Increasingly higher-end smartphone models that can perform a range of functions are now available. Smart devices have become widely popular since they provide high efficiency and great convenience for not only private daily activities but also business endeavors. Rapid advancements have been achieved in smart device technologies to improve the end users' convenience. Consequently, many people increasingly rely on smart devices to store their valuable and important data. With this increasing dependence, an important aspect that must be addressed is security issues. Leaking of private information or sensitive business data due to loss or theft of smart devices could result in exorbitant damage. To mitigate these security threats, basic embedded locking features are provided in smart devices. However, these locking features are vulnerable. In this paper, an original security-locking scheme using a rhythm-based locking system (RLS) is proposed to overcome the existing security problems of smart devices. RLS is a user-authenticated system that addresses vulnerability issues in the existing locking features and provides secure confidentiality in addition to convenience. PMID:25110743

  5. Robust quantum data locking from phase modulation

    NASA Astrophysics Data System (ADS)

    Lupo, Cosmo; Wilde, Mark M.; Lloyd, Seth

    2014-08-01

    Quantum data locking is a uniquely quantum phenomenon that allows a relatively short key of constant size to (un)lock an arbitrarily long message encoded in a quantum state, in such a way that an eavesdropper who measures the state but does not know the key has essentially no information about the message. The application of quantum data locking in cryptography would allow one to overcome the limitations of the one-time pad encryption, which requires the key to have the same length as the message. However, it is known that the strength of quantum data locking is also its Achilles heel, as the leakage of a few bits of the key or the message may in principle allow the eavesdropper to unlock a disproportionate amount of information. In this paper we show that there exist quantum data locking schemes that can be made robust against information leakage by increasing the length of the key by a proportionate amount. This implies that a constant size key can still lock an arbitrarily long message as long as a fraction of it remains secret to the eavesdropper. Moreover, we greatly simplify the structure of the protocol by proving that phase modulation suffices to generate strong locking schemes, paving the way to optical experimental realizations. Also, we show that successful data locking protocols can be constructed using random code words, which very well could be helpful in discovering random codes for data locking over noisy quantum channels.

  6. U.S. Geological Survey common-depth-point seismic-reflection survey between Mississippi River miles 195 to 210 (R/V NEECHO, cruise NE-80-3)

    USGS Publications Warehouse

    Winget, E.A.; Tirey, G.B.

    1984-01-01

    In December 1980, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (COE), conducted a seismic survey of the Mississippi River in the vicinity of Alton, Illinois, near St. Louis, Missouri (fig. 1). Seismic lines were run from the mouth of the Missouri River up the Mississippi River to a point approximately seven miles upriver from Lock and Dam No. 26 at Alton, Illinois (fig. 2a,b). Additional lines were run upriver from Lock and Dam No. 25 between the dam and River Mile 244, but these data are not reported because of mechanical problems with the larger sound-source equipment and inexact navigational control. The objective of the cooperative study was to utilize marine common-depth-point (CDP), digital, and multichannel techniques to locate a monoclinal flexure of the Cap au Gres Fault that earlier had been interpreted from land seismic data to be in the vicinity of Lock and Dam No 26 (Shannon and Wilson, 1980). A second objective was to demonstrate that the marine seismic system could be used for making relatively deep penetration seismic-reflection surveys on shallow (less than 10-m water depth) inland waterways that have organic sediment floors.

  7. 77 FR 29626 - Application Ready for Environmental Analysis and Soliciting Comments, Recommendations, Terms and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ... Hydroelectric, LLC (BOST3). e. Name of Project: Red River Lock & Dam No. 3 Hydroelectric Project. f. Location: The proposed project would be located at the existing U.S. Army Corps of Engineer's (Corps) Red River Lock & Dam No. 3 on the Red River, in Natchitoches Parish near the City of Colfax, Louisiana. The...

  8. 77 FR 785 - BOST5 Hydroelectric Company, LLC, (BOST5); Notice of Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... (BOST5). e. Name of Project: Red River Lock & Dam No. 5 Hydroelectric Project. f. Location: The proposed project would be located at the existing Army Corps of Engineer's (Corps) Red River Lock & Dam No. 5 on the Red River, in Bassier Parish near the Town of Ninock, Louisiana. g. Filed Pursuant to: Federal...

  9. 76 FR 14651 - BOST4 Hydroelectric Company, LLC; Notice of Application Tendered for Filing With the Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... (BOST4). e. Name of Project: Red River Lock & Dam No. 4 Hydroelectric Project. f. Location: The proposed project would be located at the existing Army Corps of Engineer's (Corps) Red River Lock & Dam No. 4 on the Red River, in Red River Parish near the City of Coushatta, Louisiana. g. Filed Pursuant to...

  10. 77 FR 786 - BOST4 Hydroelectric Company, LLC, (BOST4); Notice of Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... (BOST4). e. Name of Project: Red River Lock & Dam No. 4 Hydroelectric Project. f. Location: The proposed project would be located at the existing Army Corps of Engineer's (Corps) Red River Lock & Dam No. 4 on the Red River, in Red River Parish near the Town of Coushatta, Louisiana. g. Filed Pursuant to...

  11. 76 FR 14653 - BOST3 Hydroelectric Company, LLC (BOST3); Notice of Application Accepted for Filing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ...). e. Name of Project: Red River Lock & Dam No. 3 Hydroelectric Project. f. Location: The proposed project would be located at the existing Army Corps of Engineer's (Corps) Red River Lock & Dam No. 3 on the Red River, in Natchitoches Parish near the City of Colfax, Louisiana. g. Filed Pursuant to...

  12. 77 FR 29622 - Application Ready for Environmental Analysis and Soliciting Comments, Recommendations, Terms and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ..., LLC (BOST5). e. Name of Project: Red River Lock & Dam No. 5 Hydroelectric Project. f. Location: The proposed project would be located at the existing U.S. Army Corps of Engineer's (Corps) Red River Lock & Dam No. 5 on the Red River, in Bossier Parish, near the Town of Ninock, Louisiana. The proposed...

  13. 77 FR 29623 - Application Ready for Environmental Analysis and Soliciting Comments, Recommendations, Terms and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ..., LLC (BOST4). e. Name of Project: Red River Lock & Dam No. 4 Hydroelectric Project. f. Location: The proposed project would be located at the existing U. S. Army Corps of Engineer's (Corps) Red River Lock & Dam No. 4 on the Red River, in Red River Parish near the Town of Coushatta, Louisiana. The proposed...

  14. 77 FR 38780 - Proposed Reduction in Hours of Operation at the Mississippi River Twin Cities Locks Located in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... will be closed to lockages between 2:00 a.m. and 7:00 a.m. Constrained funding has led to reduced Operations and Maintenance funding within the Corps' Inland Marine Transportation System (IMTS). The intended effect of the proposed change reduces operational costs and aligns lock availability with existing levels...

  15. 77 FR 35662 - Intent To Prepare a Draft Supplemental Environmental Impact Statement for the Greenup Locks and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-14

    ... project in April 2000. This study recommended a 600- foot (ft) extension of the existing auxiliary lock chamber to a length of 1200 ft. The project was authorized by Congress in 2000; however, no funds have been appropriated for project construction. Due to the amount of time that has elapsed since completion...

  16. Injection locking of a two-mode electron oscillator with close frequencies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Starodubova, E. N.; Usacheva, S. A.; Ryskin, N. M.

    2015-03-15

    Theory of injection locking is developed for a two-mode electron maser with close frequencies, when the driving signal affects both modes. There exist two regimes of phase locking in which either first or second mode dominates. Hard transitions between the two regimes are observed with variation of the driving frequency. The results of numerical simulations are presented for the case of driving by a signal with linear frequency chirp, as well as by a signal with sinusoidal frequency modulation. The effect of bifurcation delay is observed with the increase of chirp rate.

  17. Coordinating sensing and local navigation

    NASA Technical Reports Server (NTRS)

    Slack, Marc G.

    1991-01-01

    Based on Navigation Templates (or NaTs), this work presents a new paradigm for local navigation which addresses the noisy and uncertain nature of sensor data. Rather than creating a new navigation plan each time the robot's perception of the world changes, the technique incorporates perceptual changes directly into the existing navigation plan. In this way, the robot's navigation plan is quickly and continuously modified, resulting in actions that remain coordinated with its changing perception of the world.

  18. Locked-in: the syndrome as depicted in literature.

    PubMed

    Haan, Joost

    2013-01-01

    Protagonists who are locked-in can be found throughout fiction, probably because being locked-in serves as a strong philosophical metaphor for human existence. In this chapter, three protagonists who are locked-in due to physical/medical reasons will be described. The fictitious stories of Noirtier from The Count of Monte Cristo by Alexandre Dumas and that of Madame Raquin from Thérèse Raquin by Émile Zola are followed by the real-life story of Jean-Dominique Bauby's The Diving Bell and the Butterfly. Dumas' Noirtier is considered the first description of the locked-in syndrome in literature, and Madame Raquin appears to be locked-in also, but her description leaves many questions. Bauby's autopathography is chosen from many several similar discourses as it contains cross-references to Noirtier, Dumas' prototype of the syndrome, but also because it is of high literary value. The similarities and remarkable differences between these three case reports of this existentialistically important state of being will be highlighted, with an emphasis on the focus of their narratives. © 2013 Elsevier B.V. All rights reserved.

  19. A Research Design for Archaeological Investigations and Architectural Evaluations within the Proposed Upper Site, New Lock and Connecting Channels, Inner Harbor Navigation Canal, New Orleans, Louisiana

    DTIC Science & Technology

    1991-02-27

    balance of trade at this date. Planters owed over three million livres for previous shipments of slaves and supplies. By that time, structures within New...Delavigine (Lots 7 to 18). The frame buildings lying within the projected passage of Jourdan Avenue between Maurais and St. Claude, were purchased by...the top lends additional rigidity. It was also justified at South Halsted Street to provide machinists with quick passage from the top of one tower

  20. National Waterways Study Overview of the Transportation Industry.

    DTIC Science & Technology

    1981-08-01

    Guard. The Corps has provided and maintained most of the channels, basins , dams, locks, breakwaters and jetties used as part of the navigation system...Producing Areas L 6AAX UXA*A 4. "T410~g IC.4 PIMMGCMU P’A M e.~ " .4 24 6mg -,41 )a%2," .4-. ifew All BasinIz2 ,1 Uinta "A’ SOURCE: A Technological...governments through such organizations as the river basin commissions established in accordance with Title II of the Water Resources Planning Act of 1965

  1. NFC Internal: An Indoor Navigation System

    PubMed Central

    Ozdenizci, Busra; Coskun, Vedat; Ok, Kerem

    2015-01-01

    Indoor navigation systems have recently become a popular research field due to the lack of GPS signals indoors. Several indoors navigation systems have already been proposed in order to eliminate deficiencies; however each of them has several technical and usability limitations. In this study, we propose NFC Internal, a Near Field Communication (NFC)-based indoor navigation system, which enables users to navigate through a building or a complex by enabling a simple location update, simply by touching NFC tags those are spread around and orient users to the destination. In this paper, we initially present the system requirements, give the design details and study the viability of NFC Internal with a prototype application and a case study. Moreover, we evaluate the performance of the system and compare it with existing indoor navigation systems. It is seen that NFC Internal has considerable advantages and significant contributions to existing indoor navigation systems in terms of security and privacy, cost, performance, robustness, complexity, user preference and commercial availability. PMID:25825976

  2. Geodetic exploration of strain along the El Pilar Fault in northeastern Venezuela

    NASA Astrophysics Data System (ADS)

    Reinoza, C.; Jouanne, F.; Audemard, F. A.; Schmitz, M.; Beck, C.

    2015-03-01

    We use Global Navigation Satellite Systems observations in northeastern Venezuela to constrain the El Pilar Fault (EPF) kinematics and to explore the effects of the variable elastic properties of the surrounding medium and of the fault geometry on inferred slip rates and locking depth. The velocity field exhibits an asymmetric velocity gradient on either side of the EPF. We use five different approaches to explore possible models to explain this asymmetry. First, we infer a 1.6 km locking depth using a classic elastic half-space dislocation model. Second, we infer a 1.5 km locking depth and a 0.33 asymmetry coefficient using a heterogeneous asymmetric model, including contrasting material properties on either side of a vertical fault, suggesting that the igneous-metamorphic terranes on the northern side are ~2 times more rigid than the sedimentary southern side. Third, we use a three-dimensional elastostatic model to evaluate the presence of a compliant zone, suggesting a 30% reduction of rigidity in the upper 3 km at the depth of a 1 to 5 km wide fault zone. Fourth, we evaluate the distribution of fault slip, revealing a widespread partial creep pattern in the eastern upper segment, while the upper western segment exhibits a partially locked area, which coincides with the rupture surface of the 1797 and 1929 earthquakes. To supplement these models, we upgrade the previously published displacement simulation method using nonvertical dislocations with data acquired between 2003 and 2013. The localized aseismic displacement pattern associated with creeping or partially creeping fault segments could explain the low level of historic seismicity.

  3. Evaluating upstream passage and timing of approach by adult bigheaded carps at a gated dam on the Illinois River

    USGS Publications Warehouse

    Lubejko, Matthew; Whitledge, Greg; Coulter, Alison A.; Brey, Marybeth; Oliver, Devon; Garvey, James E.

    2017-01-01

    Dams are a conservation threat because they function as barriers to native fish movement; however, they may prevent the spread of invasive species. Invasive bigheaded carps (Hypophthalmichthys spp.) threaten the Great Lakes ecosystem and are advancing towards Lake Michigan via the Illinois River. Navigation dams on the Illinois River may deter bigheaded carps' upstream movement. We investigated the permeability of the Starved Rock Lock and Dam (SRLD), the most downstream gated Illinois River dam, to bigheaded carps' migration by examining the timing of individuals approaching and passing through SRLD in relation to gate openness, tailwater elevation, and water temperature. Using acoustic telemetry of (N = ~104 per year) tagged fish, 13 upstream passages of bigheaded carps occurred through SRLD between 2013 and 2016. Eleven passages occurred through the dam gates and 2 through the lock chamber, indicating deterrents (e.g., CO2) placed in SRLD lock chamber may only limit passage of a small proportion of all fish passing through the lock-and-dam structure. Passages were documented only in 2013 and 2015. Most of the dam gate passages occurred during high water when gates were completely out of the water. Timing of bigheaded carps approaching SRLD was positively correlated with rising water temperature and high tailwater elevation, and all fish approached during late March through mid-September. Movement through dams is rare; modifying gate operations to reduce gate openness during late spring and summer could further reduce the permeability of gated dams such as SRLD to bigheaded carps, slowing their upstream advance.

  4. 76 FR 21885 - BOST5 Hydroelectric Company, LLC; Notice of Application Tendered for Filing With the Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... (BOST5). e. Name of Project: Red River Lock & Dam No. 5 Hydroelectric Project. f. Location: The proposed project would be located at the existing Army Corps of Engineer's (Corps) Red River Lock & Dam No. 5 on the Red River, near the town of Ninock near the City of Shreveport, Louisiana. g. Filed Pursuant to...

  5. Coherent beam combination using self-phase locked stimulated Brillouin scattering phase conjugate mirrors with a rotating wedge for high power laser generation.

    PubMed

    Park, Sangwoo; Cha, Seongwoo; Oh, Jungsuk; Lee, Hwihyeong; Ahn, Heekyung; Churn, Kil Sung; Kong, Hong Jin

    2016-04-18

    The self-phase locking of a stimulated Brillouin scattering-phase conjugate mirror (SBS-PCM) allows a simple and scalable coherent beam combination of existing lasers. We propose a simple optical system composed of a rotating wedge and a concave mirror to overcome the power limit of the SBS-PCM. Its phase locking ability and the usefulness on the beam-combination laser are demonstrated experimentally. A four-beam combination is demonstrated using this SBS-PCM scheme. The relative phases between the beams were measured to be less than λ/24.7.

  6. Error field penetration and locking to the backward propagating wave

    DOE PAGES

    Finn, John M.; Cole, Andrew J.; Brennan, Dylan P.

    2015-12-30

    In this letter we investigate error field penetration, or locking, behavior in plasmas having stable tearing modes with finite real frequencies w r in the plasma frame. In particular, we address the fact that locking can drive a significant equilibrium flow. We show that this occurs at a velocity slightly above v = w r/k, corresponding to the interaction with a backward propagating tearing mode in the plasma frame. Results are discussed for a few typical tearing mode regimes, including a new derivation showing that the existence of real frequencies occurs for viscoresistive tearing modes, in an analysis including themore » effects of pressure gradient, curvature and parallel dynamics. The general result of locking to a finite velocity flow is applicable to a wide range of tearing mode regimes, indeed any regime where real frequencies occur.« less

  7. Particle size distribution of main-channel-bed sediments along the upper Mississippi River, USA

    USGS Publications Warehouse

    Remo, Jonathan; Heine, Ruben A.; Ickes, Brian

    2016-01-01

    In this study, we compared pre-lock-and-dam (ca. 1925) with a modern longitudinal survey of main-channel-bed sediments along a 740-km segment of the upper Mississippi River (UMR) between Davenport, IA, and Cairo, IL. This comparison was undertaken to gain a better understanding of how bed sediments are distributed longitudinally and to assess change since the completion of the UMR lock and dam navigation system and Missouri River dams (i.e., mid-twentieth century). The comparison of the historic and modern longitudinal bed sediment surveys showed similar bed sediment sizes and distributions along the study segment with the majority (> 90%) of bed sediment samples having a median diameter (D50) of fine to coarse sand. The fine tail (≤ D10) of the sediment size distributions was very fine to medium sand, and the coarse tail (≥ D90) of sediment-size distribution was coarse sand to gravel. Coarsest sediments in both surveys were found within or immediately downstream of bedrock-floored reaches. Statistical analysis revealed that the particle-size distributions between the survey samples were statistically identical, suggesting no overall difference in main-channel-bed sediment-size distribution between 1925 and present. This was a surprising result given the magnitude of river engineering undertaken along the study segment over the past ~ 90 years. The absence of substantial differences in main-channel-bed-sediment size suggests that flow competencies within the highly engineered navigation channel today are similar to conditions within the less-engineered historic channel.

  8. Structural dissipative solitons in passive mode-locked fiber lasers.

    PubMed

    Komarov, Andrey; Sanchez, François

    2008-06-01

    On the basis of numerical simulation of fiber laser passive mode locking with anomalous dispersion we have found the dissipative solitons with powerful pedestals having oscillating structure. The pedestal structure causes a complex structural spectrum. These solitons can be multistable: with the same laser parameters the pedestals can have different structures. For some nonlinear-dispersion parameters there exist solitons with asymmetric structural pedestals moving relatively solitons with symmetric ones.

  9. Kuramoto model with uniformly spaced frequencies: Finite-N asymptotics of the locking threshold.

    PubMed

    Ottino-Löffler, Bertrand; Strogatz, Steven H

    2016-06-01

    We study phase locking in the Kuramoto model of coupled oscillators in the special case where the number of oscillators, N, is large but finite, and the oscillators' natural frequencies are evenly spaced on a given interval. In this case, stable phase-locked solutions are known to exist if and only if the frequency interval is narrower than a certain critical width, called the locking threshold. For infinite N, the exact value of the locking threshold was calculated 30 years ago; however, the leading corrections to it for finite N have remained unsolved analytically. Here we derive an asymptotic formula for the locking threshold when N≫1. The leading correction to the infinite-N result scales like either N^{-3/2} or N^{-1}, depending on whether the frequencies are evenly spaced according to a midpoint rule or an end-point rule. These scaling laws agree with numerical results obtained by Pazó [D. Pazó, Phys. Rev. E 72, 046211 (2005)PLEEE81539-375510.1103/PhysRevE.72.046211]. Moreover, our analysis yields the exact prefactors in the scaling laws, which also match the numerics.

  10. 33 CFR 83.14 - Head-on situation (Rule 14).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Head-on situation (Rule 14). 83... situation (Rule 14). (a) Course alterations to starboard; port side passage. Unless otherwise agreed, when... other. (b) Existence of head-on situation. Such a situation shall be deemed to exist when a vessel sees...

  11. Open-source platforms for navigated image-guided interventions.

    PubMed

    Ungi, Tamas; Lasso, Andras; Fichtinger, Gabor

    2016-10-01

    Navigation technology is changing the clinical standards in medical interventions by making existing procedures more accurate, and new procedures possible. Navigation is based on preoperative or intraoperative imaging combined with 3-dimensional position tracking of interventional tools registered to the images. Research of navigation technology in medical interventions requires significant engineering efforts. The difficulty of developing such complex systems has been limiting the clinical translation of new methods and ideas. A key to the future success of this field is to provide researchers with platforms that allow rapid implementation of applications with minimal resources spent on reimplementing existing system features. A number of platforms have been already developed that can share data in real time through standard interfaces. Complete navigation systems can be built using these platforms using a layered software architecture. In this paper, we review the most popular platforms, and show an effective way to take advantage of them through an example surgical navigation application. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Analysis of the PLL phase error in presence of simulated ionospheric scintillation events

    NASA Astrophysics Data System (ADS)

    Forte, B.

    2012-01-01

    The functioning of standard phase locked loops (PLL), including those used to track radio signals from Global Navigation Satellite Systems (GNSS), is based on a linear approximation which holds in presence of small phase errors. Such an approximation represents a reasonable assumption in most of the propagation channels. However, in presence of a fading channel the phase error may become large, making the linear approximation no longer valid. The PLL is then expected to operate in a non-linear regime. As PLLs are generally designed and expected to operate in their linear regime, whenever the non-linear regime comes into play, they will experience a serious limitation in their capability to track the corresponding signals. The phase error and the performance of a typical PLL embedded into a commercial multiconstellation GNSS receiver were analyzed in presence of simulated ionospheric scintillation. Large phase errors occurred during scintillation-induced signal fluctuations although cycle slips only occurred during the signal re-acquisition after a loss of lock. Losses of lock occurred whenever the signal faded below the minimumC/N0threshold allowed for tracking. The simulations were performed for different signals (GPS L1C/A, GPS L2C, GPS L5 and Galileo L1). L5 and L2C proved to be weaker than L1. It appeared evident that the conditions driving the PLL phase error in the specific case of GPS receivers in presence of scintillation-induced signal perturbations need to be evaluated in terms of the combination of the minimumC/N0 tracking threshold, lock detector thresholds, possible cycle slips in the tracking PLL and accuracy of the observables (i.e. the error propagation onto the observables stage).

  13. 33 CFR 64.31 - Determination of hazard to navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS Miscellaneous...) Location of the obstruction in relation to other obstructions or aids to navigation; (h) Prevailing and historical weather conditions; (i) Length of time that the obstruction has been in existence; (j) History of...

  14. 33 CFR 64.31 - Determination of hazard to navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS Miscellaneous...) Location of the obstruction in relation to other obstructions or aids to navigation; (h) Prevailing and historical weather conditions; (i) Length of time that the obstruction has been in existence; (j) History of...

  15. 33 CFR 64.31 - Determination of hazard to navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS Miscellaneous...) Location of the obstruction in relation to other obstructions or aids to navigation; (h) Prevailing and historical weather conditions; (i) Length of time that the obstruction has been in existence; (j) History of...

  16. 33 CFR 64.31 - Determination of hazard to navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS Miscellaneous...) Location of the obstruction in relation to other obstructions or aids to navigation; (h) Prevailing and historical weather conditions; (i) Length of time that the obstruction has been in existence; (j) History of...

  17. 33 CFR 64.31 - Determination of hazard to navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS Miscellaneous...) Location of the obstruction in relation to other obstructions or aids to navigation; (h) Prevailing and historical weather conditions; (i) Length of time that the obstruction has been in existence; (j) History of...

  18. Biological Survey Along the St. Lawrence River for the St. Lawrence Seaway. Additional Locks and other Navigation Improvements Study.

    DTIC Science & Technology

    1979-01-01

    shiner K X K x No trps- FeathT6i des Emerald shiner K K K K K K NotroDP-s bifrenatus Bridle shiner K K K K K NiitoTi’ Tcornutus Commnon shiner K K K K K...Phleum pratense, Dactylis glomerata, Bromus inermis) (Geis, Hyduke, Gilman, Ruta , and Faust 1976) are dominant in the agricultural * llands and...P. Ruta and M.E. Faust. 1976. Plant communities along the St. Lawrence River Shoreline in New York State. SUNY College of Envir. Scl. and Forestry

  19. The performance of a sampled data delay lock loop implemented with a Kalman loop filter

    NASA Astrophysics Data System (ADS)

    Eilts, H. S.

    1980-01-01

    The purpose of this study is to evaluate the steady-state and transient (lock-up) performance of a tracking loop implemented with a Kalman filter. Steady-state performance criteria are errors due to measurement noise (jitter) and Doppler errors due to motion of the tracking loop. Trade-offs exist between the two criteria such that increasing performance with respect to either one will cause performance decrease with respect to the other. It is shown that by carefully selecting filter parameters reasonable performance can be obtained for both criteria simultaneously. It is also shown that lock-up performance for the loop is acceptable when these parameters are used.

  20. Existence and stability of limit cycles in control of anti-lock braking systems with two boundaries via perturbation theory

    NASA Astrophysics Data System (ADS)

    Köppen, Thomas; Küpper, Tassilo; Makarenkov, Oleg

    2017-05-01

    This paper presents a two-phase control logic for anti-lock braking systems (ABS). ABS are by now a standard component in every modern car, preventing the wheels from going into a lock situation where the wheels are fixed by the brake and the stopping distances are greatly prolonged. There are different approaches to such control logics. An ABS design proposed in recent literature controls the wheel's slip by creating stable limit cycles in the corresponding phase space. This design is modified via an analytical approach that is derived from perturbation theory. Simulation results document shorter braking distance compared to available tests in the literature.

  1. 76 FR 72442 - Certain Automotive GPS Navigation Systems, Components Thereof, and Products Containing Same...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-814] Certain Automotive GPS Navigation Systems... the sale within the United States after importation of certain automotive GPS navigation systems... further alleges that an industry in the United States exists as required by subsection (a)(2) of section...

  2. Instrumentation for one-way satellite PTTI applications. [calibration and synchronization of clocks from navigation satellite

    NASA Technical Reports Server (NTRS)

    Osborne, A. E.

    1973-01-01

    A review of general principles and operational procedures illustrates how the typical passive user and omni receiving antenna can recover Precise Time and Time Interval (PTTI) information from a low altitude navigation satellite system for clock calibration and synchronization. Detailed discussions of concepts and theory of the receiver design are presented. The importance of RF correlation of the received and local PN encoded sequences is emphasized as a means of reducing delay uncertainties of the instrumentation to values compatible with nanosecond to submicrosecond PTTI objectives. Two receiver configurations were fabricated for use in satellite-to-laboratory experiments. In one receiver the delay-locked loop for PN signals synchronization used a dithered amplitude detection process while the second receiver used a complex sums phase detection method for measurement of delay error. The necessity for compensation of Doppler shift is discussed. Differences in theoretical signal acquisition and tracking performance of the design concepts are noted.

  3. From self-assessment to frustration, a small step toward autonomy in robotic navigation

    PubMed Central

    Jauffret, Adrien; Cuperlier, Nicolas; Tarroux, Philippe; Gaussier, Philippe

    2013-01-01

    Autonomy and self-improvement capabilities are still challenging in the fields of robotics and machine learning. Allowing a robot to autonomously navigate in wide and unknown environments not only requires a repertoire of robust strategies to cope with miscellaneous situations, but also needs mechanisms of self-assessment for guiding learning and for monitoring strategies. Monitoring strategies requires feedbacks on the behavior's quality, from a given fitness system in order to take correct decisions. In this work, we focus on how a second-order controller can be used to (1) manage behaviors according to the situation and (2) seek for human interactions to improve skills. Following an incremental and constructivist approach, we present a generic neural architecture, based on an on-line novelty detection algorithm that may be able to self-evaluate any sensory-motor strategies. This architecture learns contingencies between sensations and actions, giving the expected sensation from the previous perception. Prediction error, coming from surprising events, provides a measure of the quality of the underlying sensory-motor contingencies. We show how a simple second-order controller (emotional system) based on the prediction progress allows the system to regulate its behavior to solve complex navigation tasks and also succeeds in asking for help if it detects dead-lock situations. We propose that this model could be a key structure toward self-assessment and autonomy. We made several experiments that can account for such properties for two different strategies (road following and place cells based navigation) in different situations. PMID:24115931

  4. Artifacts correction for T1rho imaging with constant amplitude spin-lock

    NASA Astrophysics Data System (ADS)

    Chen, Weitian

    2017-01-01

    T1rho imaging with constant amplitude spin-lock is prone to artifacts in the presence of B1 RF and B0 field inhomogeneity. Despite significant technological progress, improvements on the robustness of constant amplitude spin-lock are necessary in order to use it for routine clinical practice. This work proposes methods to simultaneously correct for B1 RF and B0 field inhomogeneity in constant amplitude spin-lock. By setting the maximum B1 amplitude of the excitation adiabatic pulses equal to the expected constant amplitude spin-lock frequency, the spins become aligned along the effective field throughout the spin-lock process. This results in T1rho-weighted images free of artifacts, despite the spatial variation of the effective field caused by B1 RF and B0 field inhomogeneity. When the pulse is long, the relaxation effect during the adiabatic half passage may result in a non-negligible error in the mono-exponential relaxation model. A two-acquisition approach is presented to solve this issue. Simulation, phantom, and in-vivo scans demonstrate the proposed methods achieve superior image quality compared to existing methods, and that the two-acquisition method is effective in resolving the relaxation effect during the adiabatic half passage.

  5. Optimal motion planning using navigation measure

    NASA Astrophysics Data System (ADS)

    Vaidya, Umesh

    2018-05-01

    We introduce navigation measure as a new tool to solve the motion planning problem in the presence of static obstacles. Existence of navigation measure guarantees collision-free convergence at the final destination set beginning with almost every initial condition with respect to the Lebesgue measure. Navigation measure can be viewed as a dual to the navigation function. While the navigation function has its minimum at the final destination set and peaks at the obstacle set, navigation measure takes the maximum value at the destination set and is zero at the obstacle set. A linear programming formalism is proposed for the construction of navigation measure. Set-oriented numerical methods are utilised to obtain finite dimensional approximation of this navigation measure. Application of the proposed navigation measure-based theoretical and computational framework is demonstrated for a motion planning problem in a complex fluid flow.

  6. Passively mode-locked interband cascade optical frequency combs.

    PubMed

    Bagheri, Mahmood; Frez, Clifford; Sterczewski, Lukasz A; Gruidin, Ivan; Fradet, Mathieu; Vurgaftman, Igor; Canedy, Chadwick L; Bewley, William W; Merritt, Charles D; Kim, Chul Soo; Kim, Mijin; Meyer, Jerry R

    2018-02-20

    Since their inception, optical frequency combs have transformed a broad range of technical and scientific disciplines, spanning time keeping to navigation. Recently, dual comb spectroscopy has emerged as an attractive alternative to traditional Fourier transform spectroscopy, since it offers higher measurement sensitivity in a fraction of the time. Midwave infrared (mid-IR) frequency combs are especially promising as an effective means for probing the strong fundamental absorption lines of numerous chemical and biological agents. Mid-IR combs have been realized via frequency down-conversion of a near-IR comb, by optical pumping of a micro-resonator, and beyond 7 μm by four-wave mixing in a quantum cascade laser. In this work, we demonstrate an electrically-driven frequency comb source that spans more than 1 THz of bandwidth centered near 3.6 μm. This is achieved by passively mode-locking an interband cascade laser (ICL) with gain and saturable absorber sections monolithically integrated on the same chip. The new source will significantly enhance the capabilities of mid-IR multi-heterodyne frequency comb spectroscopy systems.

  7. Applicability of Deep-Learning Technology for Relative Object-Based Navigation

    DTIC Science & Technology

    2017-09-01

    burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instruction, searching existing...possible selections for navigating an unmanned ground vehicle (UGV) is through real- time visual odometry. To navigate in such an environment, the UGV...UGV) is through real- time visual odometry. To navigate in such an environment, the UGV needs to be able to detect, identify, and relate the static

  8. Fringe pattern demodulation with a two-dimensional digital phase-locked loop algorithm.

    PubMed

    Gdeisat, Munther A; Burton, David R; Lalor, Michael J

    2002-09-10

    A novel technique called a two-dimensional digital phase-locked loop (DPLL) for fringe pattern demodulation is presented. This algorithm is more suitable for demodulation of fringe patterns with varying phase in two directions than the existing DPLL techniques that assume that the phase of the fringe patterns varies only in one direction. The two-dimensional DPLL technique assumes that the phase of a fringe pattern is continuous in both directions and takes advantage of the phase continuity; consequently, the algorithm has better noise performance than the existing DPLL schemes. The two-dimensional DPLL algorithm is also suitable for demodulation of fringe patterns with low sampling rates, and it outperforms the Fourier fringe analysis technique in this aspect.

  9. Janus and Huygens Dipoles: Near-Field Directionality Beyond Spin-Momentum Locking.

    PubMed

    Picardi, Michela F; Zayats, Anatoly V; Rodríguez-Fortuño, Francisco J

    2018-03-16

    Unidirectional scattering from circularly polarized dipoles has been demonstrated in near-field optics, where the quantum spin-Hall effect of light translates into spin-momentum locking. By considering the whole electromagnetic field, instead of its spin component alone, near-field directionality can be achieved beyond spin-momentum locking. This unveils the existence of the Janus dipole, with side-dependent topologically protected coupling to waveguides, and reveals the near-field directionality of Huygens dipoles, generalizing Kerker's condition. Circular dipoles, together with Huygens and Janus sources, form the complete set of all possible directional dipolar sources in the far- and near-field. This allows the designing of directional emission, scattering, and waveguiding, fundamental for quantum optical technology, integrated nanophotonics, and new metasurface designs.

  10. Janus and Huygens Dipoles: Near-Field Directionality Beyond Spin-Momentum Locking

    NASA Astrophysics Data System (ADS)

    Picardi, Michela F.; Zayats, Anatoly V.; Rodríguez-Fortuño, Francisco J.

    2018-03-01

    Unidirectional scattering from circularly polarized dipoles has been demonstrated in near-field optics, where the quantum spin-Hall effect of light translates into spin-momentum locking. By considering the whole electromagnetic field, instead of its spin component alone, near-field directionality can be achieved beyond spin-momentum locking. This unveils the existence of the Janus dipole, with side-dependent topologically protected coupling to waveguides, and reveals the near-field directionality of Huygens dipoles, generalizing Kerker's condition. Circular dipoles, together with Huygens and Janus sources, form the complete set of all possible directional dipolar sources in the far- and near-field. This allows the designing of directional emission, scattering, and waveguiding, fundamental for quantum optical technology, integrated nanophotonics, and new metasurface designs.

  11. Concept for a Differential Lock and Traction Control Model in Automobiles

    NASA Astrophysics Data System (ADS)

    Shukul, A. K.; Hansra, S. K.

    2014-01-01

    The automobile is a complex integration of electronics and mechanical components. One of the major components is the differential which is limited due to its shortcomings. The paper proposes a concept of a cost effective differential lock and traction for passenger cars to sports utility vehicles alike, employing a parallel braking mechanism coming into action based on the relative speeds of the wheels driven by the differential. The paper highlights the employment of minimum number of components unlike the already existing systems. The system was designed numerically for the traction control and differential lock for the world's cheapest car. The paper manages to come up with all the system parameters and component costing making it a cost effective system.

  12. Concerted Interconversion between Ionic Lock Substates of the β2 Adrenergic Receptor Revealed by Microsecond Timescale Molecular Dynamics

    PubMed Central

    Romo, Tod D.; Grossfield, Alan; Pitman, Michael C.

    2010-01-01

    Abstract The recently solved crystallographic structures for the A2A adenosine receptor and the β1 and β2 adrenergic receptors have shown important differences between members of the class-A G-protein-coupled receptors and their archetypal model, rhodopsin, such as the apparent breaking of the ionic lock that stabilizes the inactive structure. Here, we characterize a 1.02 μs all-atom simulation of an apo-β2 adrenergic receptor that is missing the third intracellular loop to better understand the inactive structure. Although we find that the structure is remarkably rigid, there is a rapid influx of water into the core of the protein, as well as a slight expansion of the molecule relative to the crystal structure. In contrast to the x-ray crystal structures, the ionic lock rapidly reforms, although we see an activation-precursor-like event wherein the ionic lock opens for ∼200 ns, accompanied by movements in the transmembrane helices associated with activation. When the lock reforms, we see the structure return to its inactive conformation. We also find that the ionic lock exists in three states: closed (or locked), semi-open with a bridging water molecule, and open. The interconversion of these states involves the concerted motion of the entire protein. We characterize these states and the concerted motion underlying their interconversion. These findings may help elucidate the connection between key local events and the associated global structural changes during activation. PMID:20074514

  13. a Schema for Extraction of Indoor Pedestrian Navigation Grid Network from Floor Plans

    NASA Astrophysics Data System (ADS)

    Niu, Lei; Song, Yiquan

    2016-06-01

    The requirement of the indoor navigation related tasks such emergency evacuation calls for efficient solutions for handling data sources. Therefore, the navigation grid extraction from existing floor plans draws attentions. To this, we have to thoroughly analyse the source data, such as Autocad dxf files. Then, we could establish a sounding navigation solution, which firstly complements the basic navigation rectangle boundaries, secondly subdivides these rectangles and finally generates accessible networks with these refined rectangles. Test files are introduced to validate the whole workflow and evaluate the solution performance. In conclusion, we have achieved the preliminary step of forming up accessible network from the navigation grids.

  14. Locking classical correlations in quantum States.

    PubMed

    DiVincenzo, David P; Horodecki, Michał; Leung, Debbie W; Smolin, John A; Terhal, Barbara M

    2004-02-13

    We show that there exist bipartite quantum states which contain a large locked classical correlation that is unlocked by a disproportionately small amount of classical communication. In particular, there are (2n+1)-qubit states for which a one-bit message doubles the optimal classical mutual information between measurement results on the subsystems, from n/2 bits to n bits. This phenomenon is impossible classically. However, states exhibiting this behavior need not be entangled. We study the range of states exhibiting this phenomenon and bound its magnitude.

  15. 33 CFR 329.9 - Time at which commerce exists or determination is made.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... amend the Act, or assigns special duties of supervision and control to the Secretary of the Army or... determination is made. 329.9 Section 329.9 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DEFINITION OF NAVIGABLE WATERS OF THE UNITED STATES § 329.9 Time at which...

  16. 33 CFR 329.9 - Time at which commerce exists or determination is made.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... amend the Act, or assigns special duties of supervision and control to the Secretary of the Army or... determination is made. 329.9 Section 329.9 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DEFINITION OF NAVIGABLE WATERS OF THE UNITED STATES § 329.9 Time at which...

  17. 49 CFR 235.7 - Changes not requiring filing of application.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... formal proceeding; (2) Removal of devices and associated signals used to provide protection against... protection when the unusual contingency no longer exists; (3) Removal of an interlocking where a drawbridge... protecting a railroad crossing at grade; (9) The installation of all relay type locking to replace existing...

  18. 49 CFR 235.7 - Changes not requiring filing of application.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... formal proceeding; (2) Removal of devices and associated signals used to provide protection against... protection when the unusual contingency no longer exists; (3) Removal of an interlocking where a drawbridge... protecting a railroad crossing at grade; (9) The installation of all relay type locking to replace existing...

  19. Comparing the locking threshold for rings and chains of oscillators.

    PubMed

    Ottino-Löffler, Bertrand; Strogatz, Steven H

    2016-12-01

    We present a case study of how topology can affect synchronization. Specifically, we consider arrays of phase oscillators coupled in a ring or a chain topology. Each ring is perfectly matched to a chain with the same initial conditions and the same random natural frequencies. The only difference is their boundary conditions: periodic for a ring and open for a chain. For both topologies, stable phase-locked states exist if and only if the spread or "width" of the natural frequencies is smaller than a critical value called the locking threshold (which depends on the boundary conditions and the particular realization of the frequencies). The central question is whether a ring synchronizes more readily than a chain. We show that it usually does, but not always. Rigorous bounds are derived for the ratio between the locking thresholds of a ring and its matched chain, for a variant of the Kuramoto model that also includes a wider family of models.

  20. Comparing the locking threshold for rings and chains of oscillators

    NASA Astrophysics Data System (ADS)

    Ottino-Löffler, Bertrand; Strogatz, Steven H.

    2016-12-01

    We present a case study of how topology can affect synchronization. Specifically, we consider arrays of phase oscillators coupled in a ring or a chain topology. Each ring is perfectly matched to a chain with the same initial conditions and the same random natural frequencies. The only difference is their boundary conditions: periodic for a ring and open for a chain. For both topologies, stable phase-locked states exist if and only if the spread or "width" of the natural frequencies is smaller than a critical value called the locking threshold (which depends on the boundary conditions and the particular realization of the frequencies). The central question is whether a ring synchronizes more readily than a chain. We show that it usually does, but not always. Rigorous bounds are derived for the ratio between the locking thresholds of a ring and its matched chain, for a variant of the Kuramoto model that also includes a wider family of models.

  1. Phase-locked cluster oscillations in periodically forced integrate-and-fire-or-burst neuronal populations.

    PubMed

    Langdon, Angela J; Breakspear, Michael; Coombes, Stephen

    2012-12-01

    The minimal integrate-and-fire-or-burst neuron model succinctly describes both tonic firing and postinhibitory rebound bursting of thalamocortical cells in the sensory relay. Networks of integrate-and-fire-or-burst (IFB) neurons with slow inhibitory synaptic interactions have been shown to support stable rhythmic states, including globally synchronous and cluster oscillations, in which network-mediated inhibition cyclically generates bursting in coherent subgroups of neurons. In this paper, we introduce a reduced IFB neuronal population model to study synchronization of inhibition-mediated oscillatory bursting states to periodic excitatory input. Using numeric methods, we demonstrate the existence and stability of 1:1 phase-locked bursting oscillations in the sinusoidally forced IFB neuronal population model. Phase locking is shown to arise when periodic excitation is sufficient to pace the onset of bursting in an IFB cluster without counteracting the inhibitory interactions necessary for burst generation. Phase-locked bursting states are thus found to destabilize when periodic excitation increases in strength or frequency. Further study of the IFB neuronal population model with pulse-like periodic excitatory input illustrates that this synchronization mechanism generalizes to a broad range of n:m phase-locked bursting states across both globally synchronous and clustered oscillatory regimes.

  2. A new measurement method of coatings thickness based on lock-in thermography

    NASA Astrophysics Data System (ADS)

    Zhang, Jin-Yu; Meng, Xiang-bin; Ma, Yong-chao

    2016-05-01

    Coatings have been widely used in modern industry and it plays an important role. Coatings thickness is directly related to the performance of the functional coatings, therefore, rapid and accurate coatings thickness inspection has great significance. Existing coatings thickness measurement method is difficult to achieve fast and accurate on-site non-destructive coatings inspection due to cost, accuracy, destruction during inspection and other reasons. This paper starts from the introduction of the principle of lock-in thermography, and then performs an in-depth study on the application of lock-in thermography in coatings inspection through numerical modeling and analysis. The numerical analysis helps explore the relationship between coatings thickness and phase, and the relationship lays the foundation for accurate calculation of coatings thickness. The author sets up a lock-in thermography inspection system and uses thermal barrier coatings specimens to conduct an experiment. The specimen coatings thickness is measured and calibrated to verify the quantitative inspection. Experiment results show that the lock-in thermography method can perform fast coatings inspection and the inspection accuracy is about 95%. Therefore, the method can meet the field testing requirements for engineering projects.

  3. Port in oncology practice: 3-monthly locking with normal saline for catheter maintenance, a preliminary report.

    PubMed

    Solinas, Gianfranca; Platini, Francesca; Trivellato, Maurizio; Rigo, Carla; Alabiso, Oscar; Galetto, Alessandra S

    2017-07-14

    Patients with cancer need stable venous access using central vascular devices like central venous ports and peripherally inserted central catheters that can be used for a wide range of indications. Numerous flushing protocols exist including different frequencies for catheter locking to maintain catheter patency. The aim of this retrospective study was to evaluate the incidence of lumen occlusion of central venous ports in a group of adult cancer patients, adopting a policy of locking with normal saline every three months. This is a single-center retrospective observational study. During follow-up, we analyzed adult cancer patients who had undergone port insertion from January 1st, 2007 to August 31st, 2014. Flushing and locking were performed every three months with a syringe containing normal saline. We collected data from 381 patients with ports inserted in subclavian vein (379 patients) and in the right jugular vein (2 patients). Locking was performed during 3-monthly follow-up visits. Median follow-up was 810 days (90-2700 days). Among 381 ports, 59 were removed; the reasons for removal were: end of use (45 cases), catheter rupture (9 cases), dislocation (3 cases) and catheter-related bloodstream infection (2 cases). We had no reports of lumen occlusion. Our data suggest that locking ports with normal saline every three months is not associated with an increased risk of lumen occlusion.

  4. Temporal and Spatial Characterization of GPS Fading From Ionospheric Irregularities Under Low latitude

    NASA Astrophysics Data System (ADS)

    De Paula, E. R.; Moraes, A. D. O.; Vani, B. C.; Sobral, J. H. A.; Abdu, M. A.; Galera Monico, J. F.

    2017-12-01

    The ionosphere over the peak of the anomaly represents a treat for navigation systems based on GNSS. Brazilian territory is mostly under this harsh layer for satellite communication in general and in particular for navigation, like GPS users, where their receivers tracking performance are damaged under scintillation conditions. Ionospheric scintillation is responsible for significant degradation in the accuracy of navigation and positioning. Phase shifts accompanied by amplitude fades significantly degrades the signal-to-noise ratio of the received signal disrupting the channel and loosing navigation performance. The stronger the scintillations are, more difficulty will be for the GNSS receiver tracking loops to recover the phase and code replicas. These phenomena under specific geophysical conditions may severely affect the system availability and positioning. In this work the temporal characteristics of amplitude scintillation will be analyzed at the three available GPS frequencies, L1, L2C and L5. Aspect like fading duration and depth will be evaluated and compared among the three available frequencies for the current solar cycle. This work will use GPS scintillation data recorded during six months of data during 2014 to 2015 at three stations under Brazilian territory located near the southern crest of the equatorial ionization anomaly. The analysis will be performed focusing on the fading profile of the three frequencies comparing how the fading of those signals behave statistically between them. Aspects like loss of lock, spatial orientation between the signal across the ionospheric irregularity will also be discussed showing how much more susceptible the new frequencies might be in comparison to the widely used and studied L1 frequency.

  5. Phase-locking and bistability in neuronal networks with synaptic depression

    NASA Astrophysics Data System (ADS)

    Akcay, Zeynep; Huang, Xinxian; Nadim, Farzan; Bose, Amitabha

    2018-02-01

    We consider a recurrent network of two oscillatory neurons that are coupled with inhibitory synapses. We use the phase response curves of the neurons and the properties of short-term synaptic depression to define Poincaré maps for the activity of the network. The fixed points of these maps correspond to phase-locked modes of the network. Using these maps, we analyze the conditions that allow short-term synaptic depression to lead to the existence of bistable phase-locked, periodic solutions. We show that bistability arises when either the phase response curve of the neuron or the short-term depression profile changes steeply enough. The results apply to any Type I oscillator and we illustrate our findings using the Quadratic Integrate-and-Fire and Morris-Lecar neuron models.

  6. Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements.

    PubMed

    Olivier, Michel; Gagnon, Marc-Daniel; Habel, Joé

    2016-02-28

    When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques.

  7. Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements

    PubMed Central

    Olivier, Michel; Gagnon, Marc-Daniel; Habel, Joé

    2016-01-01

    When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques. PMID:26967924

  8. Web Navigation Sequences Automation in Modern Websites

    NASA Astrophysics Data System (ADS)

    Montoto, Paula; Pan, Alberto; Raposo, Juan; Bellas, Fernando; López, Javier

    Most today’s web sources are designed to be used by humans, but they do not provide suitable interfaces for software programs. That is why a growing interest has arisen in so-called web automation applications that are widely used for different purposes such as B2B integration, automated testing of web applications or technology and business watch. Previous proposals assume models for generating and reproducing navigation sequences that are not able to correctly deal with new websites using technologies such as AJAX: on one hand existing systems only allow recording simple navigation actions and, on the other hand, they are unable to detect the end of the effects caused by an user action. In this paper, we propose a set of new techniques to record and execute web navigation sequences able to deal with all the complexity existing in AJAX-based web sites. We also present an exhaustive evaluation of the proposed techniques that shows very promising results.

  9. 78 FR 2200 - Establishment of VOR Federal Airway V-629; Las Vegas, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-10

    ... existing routes structure for aircraft navigating in an area of marginal radar coverage. This action... navigating in an area of marginal radar coverage. VOR Federal airways are published in paragraph 6010(a) of...

  10. 33 CFR 155.130 - Exemptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.130 Exemptions... standards exist that would provide an equivalent level of protection from pollution; and (iii) The...

  11. 33 CFR 155.130 - Exemptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.130 Exemptions... standards exist that would provide an equivalent level of protection from pollution; and (iii) The...

  12. 33 CFR 155.130 - Exemptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.130 Exemptions... standards exist that would provide an equivalent level of protection from pollution; and (iii) The...

  13. 33 CFR 155.130 - Exemptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.130 Exemptions... standards exist that would provide an equivalent level of protection from pollution; and (iii) The...

  14. 33 CFR 155.130 - Exemptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR VESSELS General § 155.130 Exemptions... standards exist that would provide an equivalent level of protection from pollution; and (iii) The...

  15. A review of vapour lock issues during motor gasoline or automotive gasoline usage in piston engine aircraft

    NASA Astrophysics Data System (ADS)

    Thanikasalam, K.; Rahmat, M.; Fahmi, A. G. Mohammad; Zulkifli, A. M.; Shawal, N. Noor; Ilanchelvi, K.; Ananth, M.; Elayarasan, R.

    2018-05-01

    Since there is a developing practice of utilizing automotive fuels as flight fuel, there are higher chances of dangerous scenarios, particularly in the operation of piston aircraft engines. The use of motor vehicle gas (MOGAS) or aviation gas (AVGAS) in the operation of aviation piston engine increases the risk of vapour locking. A statistical examination of European aviation industry indicates that around 20,000 aircraft are affected either specifically or conceivably by the different negative impacts of gasoline blended with ethanol. Particularly, for most contemporary carburettor engines, there are risks associated with ethanol-admixed fuels that have potential to upset engine operation. The danger of vapour locking, which is the generation of gas bubbles inside the fuel system causing an impairment of fuel movement in the engine, is well documented particularly by studies on aircraft using MOGAS. Contrasted with AVGAS, MOGAS is inclined to demonstrate this phenomenon. Vapour lock is perhaps the leading serious problem that ought to be addressed if MOGAS is to be used as a substitute for AVGAS. Vapour lock problem is critical because it causes malfunctions to aircraft engines. Thus, an understanding of vapour handling ability of small aircraft is essential to establish safe operating confines at existing fuel temperature and pressures.

  16. Applying a Theory-Driven Framework to Guide Quality Improvement Efforts in Nursing Homes: The LOCK Model.

    PubMed

    Mills, Whitney L; Pimentel, Camilla B; Palmer, Jennifer A; Snow, A Lynn; Wewiorski, Nancy J; Allen, Rebecca S; Hartmann, Christine W

    2018-05-08

    Implementing quality improvement (QI) programs in nursing homes continues to encounter significant challenges, despite recognized need. QI approaches provide nursing home staff with opportunities to collaborate on developing and testing strategies for improving care delivery. We present a theory-driven and user-friendly adaptable framework and facilitation package to overcome existing challenges and guide QI efforts in nursing homes. The framework is grounded in the foundational concepts of strengths-based learning, observation, relationship-based teams, efficiency, and organizational learning. We adapted these concepts to QI in the nursing home setting, creating the "LOCK" framework. The LOCK framework is currently being disseminated across the Veterans Health Administration. The LOCK framework has five tenets: (a) Look for the bright spots, (b) Observe, (c) Collaborate in huddles, (d) Keep it bite-sized, and (e) facilitation. Each tenet is described. We also present a case study documenting how a fictional nursing home can implement the LOCK framework as part of a QI effort to improve engagement between staff and residents. The case study describes sample observations, processes, and outcomes. We also discuss practical applications for nursing home staff, the adaptability of LOCK for different QI projects, the specific role of facilitation, and lessons learned. The proposed framework complements national efforts to improve quality of care and quality of life for nursing home residents and may be valuable across long-term care settings and QI project types.

  17. Bézier B¯ projection

    NASA Astrophysics Data System (ADS)

    Miao, Di; Borden, Michael J.; Scott, Michael A.; Thomas, Derek C.

    2018-06-01

    In this paper we demonstrate the use of B\\'{e}zier projection to alleviate locking phenomena in structural mechanics applications of isogeometric analysis. Interpreting the well-known $\\bar{B}$ projection in two different ways we develop two formulations for locking problems in beams and nearly incompressible elastic solids. One formulation leads to a sparse symmetric symmetric system and the other leads to a sparse non-symmetric system. To demonstrate the utility of B\\'{e}zier projection for both geometry and material locking phenomena we focus on transverse shear locking in Timoshenko beams and volumetric locking in nearly compressible linear elasticity although the approach can be applied generally to other types of locking phenemona as well. B\\'{e}zier projection is a local projection technique with optimal approximation properties, which in many cases produces solutions that are comparable to global $L^2$ projection. In the context of $\\bar{B}$ methods, the use of B\\'ezier projection produces sparse stiffness matrices with only a slight increase in bandwidth when compared to standard displacement-based methods. Of particular importance is that the approach is applicable to any spline representation that can be written in B\\'ezier form like NURBS, T-splines, LR-splines, etc. We discuss in detail how to integrate this approach into an existing finite element framework with minimal disruption through the use of B\\'ezier extraction operators and a newly introduced dual basis for the B\\'{e}zierprojection operator. We then demonstrate the behavior of the two proposed formulations through several challenging benchmark problems.

  18. New methods of generation of ultrashort laser pulses for ranging

    NASA Technical Reports Server (NTRS)

    Jelinkova, Helena; Hamal, Karel; Kubecek, V.; Prochazka, Ivan

    1993-01-01

    To reach the millimeter satellite laser ranging accuracy, the goal for nineties, new laser ranging techniques have to be applied. To increase the laser ranging precision, the application of the ultrashort laser pulses in connection with the new signal detection and processing techniques, is inevitable. The two wavelength laser ranging is one of the ways to measure the atmospheric dispersion to improve the existing atmospheric correction models and hence, to increase the overall system ranging accuracy to the desired value. We are presenting a review of several nonstandard techniques of ultrashort laser pulses generation, which may be utilized for laser ranging: compression of the nanosecond pulses using stimulated Brillouin and Raman backscattering; compression of the mode-locked pulses using Raman backscattering; passive mode-locking technique with nonlinear mirror; and passive mode-locking technique with the negative feedback.

  19. Quantum-locked key distribution at nearly the classical capacity rate.

    PubMed

    Lupo, Cosmo; Lloyd, Seth

    2014-10-17

    Quantum data locking is a protocol that allows for a small secret key to (un)lock an exponentially larger amount of information, hence yielding the strongest violation of the classical one-time pad encryption in the quantum setting. This violation mirrors a large gap existing between two security criteria for quantum cryptography quantified by two entropic quantities: the Holevo information and the accessible information. We show that the latter becomes a sensible security criterion if an upper bound on the coherence time of the eavesdropper's quantum memory is known. Under this condition, we introduce a protocol for secret key generation through a memoryless qudit channel. For channels with enough symmetry, such as the d-dimensional erasure and depolarizing channels, this protocol allows secret key generation at an asymptotic rate as high as the classical capacity minus one bit.

  20. 46 CFR 108.444 - Lockout valves.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... dioxide to discharge in the event of equipment failure during maintenance. (c) The lockout valve design or... extinguishing system, when the valve must be locked in the closed position. (f) Lockout valves added to existing...

  1. TDRSS Augmentation System for Satellites

    NASA Technical Reports Server (NTRS)

    Heckler, Gregory W.; Gramling, Cheryl; Valdez, Jennifer; Baldwin, Philip

    2016-01-01

    In 2015, NASA Goddard Space Flight Center (GSFC) reinvigorated the development of the TDRSS Augmentation Service for Satellites (TASS). TASS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems(GNSS) and the Tracking and Data Relay Satellite System (TDRSS). TASS leverages the existing TDRSS to provide an S-band beacon radio navigation and messaging source to users at orbital altitudes 1400 km and below.

  2. TDRSS Augmentation Service for Satellites (TASS)

    NASA Technical Reports Server (NTRS)

    Heckler, Gregory W.; Gramling, Cheryl; Valdez, Jennifer; Baldwin, Philip

    2016-01-01

    In 2015, NASA Goddard Space Flight Center (GSFC) reinvigorated the development of the TDRSS Augmentation Service for Satellites (TASS). TASS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems (GNSS) and the Tracking and Data Relay Satellite System (TDRSS). TASS leverages the existing TDRSS to provide an S-band beacon radio navigation and messaging source to users at orbital altitudes 1400 km and below.

  3. Arkansas River and Tributaries Arkansas and Oklahoma. Toad Suck Ferry Lock and Dam, Conway Water Supply Foundation Report.

    DTIC Science & Technology

    1983-06-01

    NUMBER CORE BOXES NASH IS ELEV....ION GROUND WATER 6 DIRECTION OF HOLE 3-.. E VETa DATE OLE 5/30/78 5/31/ 7’ 1,7 UtmATJON o TOP 5 OLE / 7 THICKNESS OF...JUN 83 UNCLASSIFIED F/G 13/13 NL mommmmommm 0 I~lmlIIIImEE mhEgEBhEEBhIEE E Eg //EEE n-EEEElgEl- E .II 1.0 II1 l w20 1111.25 111111’.4 1II1.6 MICROCOPY...Kerr Arkansas River Navigation System. e dam was founded on a thick shale layer of the Atoka Formation. Locally, the shale was gray to black, hard to

  4. Hybridizing matter-wave and classical accelerometers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lautier, J.; Volodimer, L.; Hardin, T.

    2014-10-06

    We demonstrate a hybrid accelerometer that benefits from the advantages of both conventional and atomic sensors in terms of bandwidth (DC to 430 Hz) and long term stability. First, the use of a real time correction of the atom interferometer phase by the signal from the classical accelerometer enables to run it at best performance without any isolation platform. Second, a servo-lock of the DC component of the conventional sensor output signal by the atomic one realizes a hybrid sensor. This method paves the way for applications in geophysics and in inertial navigation as it overcomes the main limitation of atomicmore » accelerometers, namely, the dead times between consecutive measurements.« less

  5. Global navigation satellite system receiver for weak signals under all dynamic conditions

    NASA Astrophysics Data System (ADS)

    Ziedan, Nesreen Ibrahim

    The ability of the Global Navigation Satellite System (GNSS) receiver to work under weak signal and various dynamic conditions is required in some applications. For example, to provide a positioning capability in wireless devices, or orbit determination of Geostationary and high Earth orbit satellites. This dissertation develops Global Positioning System (GPS) receiver algorithms for such applications. Fifteen algorithms are developed for the GPS C/A signal. They cover all the receiver main functions, which include acquisition, fine acquisition, bit synchronization, code and carrier tracking, and navigation message decoding. They are integrated together, and they can be used in any software GPS receiver. They also can be modified to fit any other GPS or GNSS signals. The algorithms have new capabilities. The processing and memory requirements are considered in the design to allow the algorithms to fit the limited resources of some applications; they do not require any assisting information. Weak signals can be acquired in the presence of strong interfering signals and under high dynamic conditions. The fine acquisition, bit synchronization, and tracking algorithms are based on the Viterbi algorithm and Extended Kalman filter approaches. The tracking algorithms capabilities increase the time to lose lock. They have the ability to adaptively change the integration length and the code delay separation. More than one code delay separation can be used in the same time. Large tracking errors can be detected and then corrected by a re-initialization and an acquisition-like algorithms. Detecting the navigation message is needed to increase the coherent integration; decoding it is needed to calculate the navigation solution. The decoding algorithm utilizes the message structure to enable its decoding for signals with high Bit Error Rate. The algorithms are demonstrated using simulated GPS C/A code signals, and TCXO clocks. The results have shown the algorithms ability to reliably work with 15 dB-Hz signals and acceleration over 6 g.

  6. Visual navigation using edge curve matching for pinpoint planetary landing

    NASA Astrophysics Data System (ADS)

    Cui, Pingyuan; Gao, Xizhen; Zhu, Shengying; Shao, Wei

    2018-05-01

    Pinpoint landing is challenging for future Mars and asteroid exploration missions. Vision-based navigation scheme based on feature detection and matching is practical and can achieve the required precision. However, existing algorithms are computationally prohibitive and utilize poor-performance measurements, which pose great challenges for the application of visual navigation. This paper proposes an innovative visual navigation scheme using crater edge curves during descent and landing phase. In the algorithm, the edge curves of the craters tracked from two sequential images are utilized to determine the relative attitude and position of the lander through a normalized method. Then, considering error accumulation of relative navigation, a method is developed. That is to integrate the crater-based relative navigation method with crater-based absolute navigation method that identifies craters using a georeferenced database for continuous estimation of absolute states. In addition, expressions of the relative state estimate bias are derived. Novel necessary and sufficient observability criteria based on error analysis are provided to improve the navigation performance, which hold true for similar navigation systems. Simulation results demonstrate the effectiveness and high accuracy of the proposed navigation method.

  7. Modeling of mode-locked fiber lasers

    NASA Astrophysics Data System (ADS)

    Shaulov, Gary

    This thesis presents the results of analytical and numerical simulations of mode-locked fiber lasers and their components: multiple quantum well saturable absorbers and nonlinear optical loop mirrors. Due to the growing interest in fiber lasers as a compact source of ultrashort pulses there is a need to develop a full understanding of the advantages and limitations of the different mode-locked techniques. The mode-locked fiber laser study performed in this thesis can be used to optimize the design and performance of mode-locked fiber laser systems. A group at Air Force Research Laboratory reported a fiber laser mode-locked by multiple quantum well (MQW) saturable absorber with stable pulses generated as short as 2 ps [21]. The laser cavity incorporates a chirped fiber Bragg grating as a dispersion element; our analysis showed that the laser operates in the soliton regime. Soliton perturbation theory was applied and conditions for stable pulse operation were investigated. Properties of MQW saturable absorbers and their effect on cavity dynamics were studied and the cases of fast and slow saturable absorbers were considered. Analytical and numerical results are in a good agreement with experimental data. In the case of the laser cavity with a regular fiber Bragg grating, the properties of MQW saturable absorbers dominate the cavity dynamics. It was shown that despite the lack of a soliton shaping mechanism, there is a regime in parameter space where stable or quasi-stable solitary waves solutions can exist. Further a novel technique of fiber laser mode-locking by nonlinear polarization rotation was proposed. Polarization rotation of vector solitons was simulated in a birefringent nonlinear optical loop mirror (NOLM) and the switching characteristics of this device was studied. It was shown that saturable absorber-like action of NOLM allows mode-locked operation of the two fiber laser designs. Laser cavity designs were proposed: figure-eight-type and sigma-type cavity.

  8. Study for incorporating time-synchronized approach control into the CH-47/VALT digital navigation system

    NASA Technical Reports Server (NTRS)

    Mcconnell, W. J., Jr.

    1979-01-01

    Techniques for obtaining time synchronized (4D) approach control in the VALT research helicopter is described. Various 4D concepts and their compatibility with the existing VALT digital computer navigation and guidance system hardware and software are examined. Modifications to various techniques were investigated in order to take advantage of the unique operating characteristics of the helicopter in the terminal area. A 4D system is proposed, combining the direct to maneuver with the existing VALT curved path generation capability.

  9. 33 CFR 106.305 - Facility Security Assessment (FSA) requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...

  10. 33 CFR 106.305 - Facility Security Assessment (FSA) requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...

  11. 33 CFR 106.305 - Facility Security Assessment (FSA) requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...

  12. 33 CFR 106.305 - Facility Security Assessment (FSA) requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...

  13. Maximum Correntropy Unscented Kalman Filter for Ballistic Missile Navigation System based on SINS/CNS Deeply Integrated Mode.

    PubMed

    Hou, Bowen; He, Zhangming; Li, Dong; Zhou, Haiyin; Wang, Jiongqi

    2018-05-27

    Strap-down inertial navigation system/celestial navigation system ( SINS/CNS) integrated navigation is a high precision navigation technique for ballistic missiles. The traditional navigation method has a divergence in the position error. A deeply integrated mode for SINS/CNS navigation system is proposed to improve the navigation accuracy of ballistic missile. The deeply integrated navigation principle is described and the observability of the navigation system is analyzed. The nonlinearity, as well as the large outliers and the Gaussian mixture noises, often exists during the actual navigation process, leading to the divergence phenomenon of the navigation filter. The new nonlinear Kalman filter on the basis of the maximum correntropy theory and unscented transformation, named the maximum correntropy unscented Kalman filter, is deduced, and the computational complexity is analyzed. The unscented transformation is used for restricting the nonlinearity of the system equation, and the maximum correntropy theory is used to deal with the non-Gaussian noises. Finally, numerical simulation illustrates the superiority of the proposed filter compared with the traditional unscented Kalman filter. The comparison results show that the large outliers and the influence of non-Gaussian noises for SINS/CNS deeply integrated navigation is significantly reduced through the proposed filter.

  14. Mining Missing Hyperlinks from Human Navigation Traces: A Case Study of Wikipedia.

    PubMed

    West, Robert; Paranjape, Ashwin; Leskovec, Jure

    Hyperlinks are an essential feature of the World Wide Web. They are especially important for online encyclopedias such as Wikipedia: an article can often only be understood in the context of related articles, and hyperlinks make it easy to explore this context. But important links are often missing, and several methods have been proposed to alleviate this problem by learning a linking model based on the structure of the existing links. Here we propose a novel approach to identifying missing links in Wikipedia. We build on the fact that the ultimate purpose of Wikipedia links is to aid navigation. Rather than merely suggesting new links that are in tune with the structure of existing links, our method finds missing links that would immediately enhance Wikipedia's navigability. We leverage data sets of navigation paths collected through a Wikipedia-based human-computation game in which users must find a short path from a start to a target article by only clicking links encountered along the way. We harness human navigational traces to identify a set of candidates for missing links and then rank these candidates. Experiments show that our procedure identifies missing links of high quality.

  15. Mining Missing Hyperlinks from Human Navigation Traces: A Case Study of Wikipedia

    PubMed Central

    West, Robert; Paranjape, Ashwin; Leskovec, Jure

    2015-01-01

    Hyperlinks are an essential feature of the World Wide Web. They are especially important for online encyclopedias such as Wikipedia: an article can often only be understood in the context of related articles, and hyperlinks make it easy to explore this context. But important links are often missing, and several methods have been proposed to alleviate this problem by learning a linking model based on the structure of the existing links. Here we propose a novel approach to identifying missing links in Wikipedia. We build on the fact that the ultimate purpose of Wikipedia links is to aid navigation. Rather than merely suggesting new links that are in tune with the structure of existing links, our method finds missing links that would immediately enhance Wikipedia's navigability. We leverage data sets of navigation paths collected through a Wikipedia-based human-computation game in which users must find a short path from a start to a target article by only clicking links encountered along the way. We harness human navigational traces to identify a set of candidates for missing links and then rank these candidates. Experiments show that our procedure identifies missing links of high quality. PMID:26634229

  16. Impact of depression on the intensity of patient navigation for women with abnormal cancer screenings.

    PubMed

    De La Cruz, Ignacio I; Freund, Karen M; Battaglia, Tracy A; Chen, Clara A; Bak, Sharon; Kalish, Richard; Lottero, Barbara; Egan, Patrick; Heeren, Tim; Kronman, Andrea C

    2014-02-01

    Patient navigation is increasingly being used to support vulnerable patients to receive timely and quality medical care. We sought to understand whether patients with depression utilize additional patient navigation services after abnormal cancer screening. We compared depressed and non-depressed women using three different measures of intensity of patient navigation: number of patient-navigator encounters, encounter time, and number of unique barriers to care. The study population consisted of 1,455 women who received navigation after abnormal screening for breast or cervical cancer at one of six community health centers in Boston. Navigators spent a median of 60-75 minutes over one or two encounters per participant, with 49% of participants having one or more documented barrier to care. Depressed women did not differ in total numbers of encounters, encounter time, or unique barriers compared with non-depressed women. Our findings suggest that pre-existing depression does not predict which women will utilize additional navigation services.

  17. Coherent inductive communications link for biomedical applications

    NASA Technical Reports Server (NTRS)

    Hogrefe, Arthur F. (Inventor); Radford, Wade E. (Inventor)

    1985-01-01

    A two-way coherent inductive communications link between an external transceiver and an internal transceiver located in a biologically implanted programmable medical device. Digitally formatted command data and programming data is transmitted to the implanted medical device by frequency shift keying the inductive communications link. Internal transceiver is powered by the inductive field between internal and external transceivers. Digitally formatted data is transmitted to external transceiver by internal transceiver amplitude modulating inductive field. Immediate verification of the establishment of a reliable communications link is provided by determining existence of frequency lock and bit phase lock between internal and external transceivers.

  18. Dynamics of temporally localized states in passively mode-locked semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Schelte, C.; Javaloyes, J.; Gurevich, S. V.

    2018-05-01

    We study the emergence and the stability of temporally localized structures in the output of a semiconductor laser passively mode locked by a saturable absorber in the long-cavity regime. For large yet realistic values of the linewidth enhancement factor, we disclose the existence of secondary dynamical instabilities where the pulses develop regular and subsequent irregular temporal oscillations. By a detailed bifurcation analysis we show that additional solution branches that consist of multipulse (molecules) solutions exist. We demonstrate that the various solution curves for the single and multipeak pulses can splice and intersect each other via transcritical bifurcations, leading to a complex web of solutions. Our analysis is based on a generic model of mode locking that consists of a time-delayed dynamical system, but also on a much more numerically efficient, yet approximate, partial differential equation. We compare the results of the bifurcation analysis of both models in order to assess up to which point the two approaches are equivalent. We conclude our analysis by the study of the influence of group velocity dispersion, which is only possible in the framework of the partial differential equation model, and we show that it may have a profound impact on the dynamics of the localized states.

  19. 3. View of the mouth of George Washington's 'Potowmack' Canal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of the mouth of George Washington's 'Potowmack' Canal at the Great Falls of the Potomac River. The view is taken from a rock in the Potomac River looking up into the Canal. Trees and dense growth now fill the old aperture which once permitted barges to come down the Ohio Valley onto the broad expanse of the Potomac River. This view, taken September 1, 1943, evidences the very low water then existing on the Potomac River, as is clearly shown by the water marks on the rocks on the left hand side of the photograph. That portion where the individual is standing, up to the height of his hat, is normally underwater. Deep in the sand at this spot was found a part of one of the old hand brought lock hinges which formerly swung the first lock gates ... - Potowmack Company: Great Falls Canal, Locks No. 3, 4, 5, Great Falls, Fairfax County, VA

  20. Experimental observation of different soliton types in a net-normal group-dispersion fiber laser.

    PubMed

    Feng, Zhongyao; Rong, Qiangzhou; Qiao, Xueguang; Shao, Zhihua; Su, Dan

    2014-09-20

    Different soliton types are observed in a net-normal group-dispersion fiber laser based on nonlinear polarization rotation for passive mode locking. The proposed laser can deliver a dispersion-managed soliton, typical dissipation solitons, and a quasi-harmonic mode-locked pulse, a soliton bundle, and especially a dark pulse by only appropriately adjusting the linear cavity phase delay bias using one polarization controller at the fixed pump power. These nonlinear waves show different features, including the spectral shapes and time traces. The experimental observations show that the five soliton types could exist in the same laser cavity, which implies that integrable systems, dissipative systems, and dark pulse regimes can transfer and be switched in a passively mode-locked laser. Our studies not only verify the numeral simulation of the different soliton-types formation in a net-normal group-dispersion operation but also provide insight into Ginzburg-Landau equation systems.

  1. Ultra-low noise optical phase-locked loop

    NASA Astrophysics Data System (ADS)

    Ayotte, Simon; Babin, André; Costin, François

    2014-03-01

    The relative phase between two fiber lasers is controlled via a high performance optical phase-locked loop (OPLL). Two parameters are of particular importance for the design: the intrinsic phase noise of the laser (i.e. its linewidth) and a high-gain, low-noise electronic locking loop. In this work, one of the lowest phase noise fiber lasers commercially available was selected (i.e. NP Photonics Rock fiber laser module), with sub-kHz linewidth at 1550.12 nm. However, the fast tuning mechanism of such lasers is through stretching its cavity length with a piezoelectric transducer which has a few 10s kHz bandwidth. To further increase the locking loop bandwidth to several MHz, a second tuning mechanism is used by adding a Lithium Niobate phase modulator in the laser signal path. The OPLL is thus divided into two locking loops, a slow loop acting on the laser piezoelectric transducer and a fast loop acting on the phase modulator. The beat signal between the two phase-locked lasers yields a highly pure sine wave with an integrated phase error of 0.0012 rad. This is orders of magnitude lower than similar existing systems such as the Laser Synthesizer used for distribution of photonic local oscillator (LO) for the Atacama Large Millimeter Array radio telescope in Chile. Other applications for ultra-low noise OPLL include coherent power combining, Brillouin sensing, light detection and ranging (LIDAR), fiber optic gyroscopes, phased array antenna and beam steering, generation of LOs for next generation coherent communication systems, coherent analog optical links, terahertz generation and coherent spectroscopy.

  2. Developing Sediment Transport and Dredging Prediction Model of Ohio River at Olmsted Locks and Dams Area using HEC-RAS (1D/2D)By Ganesh Raj Ghimire1 and Bruce A. Devantier 2

    NASA Astrophysics Data System (ADS)

    Ghimire, G. R.

    2015-12-01

    Sediment deposition is a serious issue in the construction and operation of large reservoir and inland navigation projects in the United States and around the world. Olmsted Locks and Dams in the Ohio River navigation system is facing similar challenges of huge sediment deposition during the ongoing in-wet construction methodology since 1993. HEC-RAS 5.0 integrated with ArcGIS, will be used to yield unsteady 2D hydrodynamic model of Ohio River at Olmsted area. Velocity, suspended sediment, bed sediment and hydrographic survey data acquired from public archives of USGS and USACE Louisville District will be input into the model. Calibration and validation of model will be performed against the measured stage, flow and velocity data. It will be subjected to completely unsteady 1D sediment transport modeling new to HEC-RAS 5.0 which incorporates sediment load and bed gradation via a DSS file, commercial dredging and BSTEM model. Sediment model will be calibrated to replicate the historical bed volume changes. Excavated cross-sections at Olmsted area will also be used to predict the sediment volume trapped inside the ditch over the period between excavations and placement of dam shells at site. Model will attempt to replicate historical dredging volume data and compare with the deposition volume from simulation model to formulate the dredging prediction model. Hence, the results of this research will generate a model that can form a basis for scheduling the dredging event prior to the placement of off-shore cast shells replacing the current as and when required approach of dredging plan. 1 Graduate Student, Department of Civil Engineering, Southern Illinois University Carbondale Carbondale, Illinois, 62901-6603 2 Professor, Department of Civil Engineering, Southern Illinois University Carbondale Carbondale, Illinois, 62901-6603

  3. The Ionospheric Scintillation Effects on the BeiDou Signal Receiver

    PubMed Central

    He, Zhijun; Zhao, Hongbo; Feng, Wenquan

    2016-01-01

    Irregularities in the Earth’s ionosphere can make the amplitude and phase of radio signals fluctuate rapidly, which is known as ionospheric scintillation. Severe ionospheric scintillation could affect the performance of the Global Navigation Satellite System (GNSS). Currently, the Multiple Phase Screen (MPS) technique is widely used in solving problems caused by weak and strong scintillations. Considering that Southern China is mainly located in the area where moderate and intense scintillation occur frequently, this paper built a model based on the MPS technique and discussed the scintillation impacts on China’s BeiDou navigation system. By using the BeiDou B1I signal, this paper analyzed the scintillation effects on the receiver, which includes the acquisition and tracking process. For acquisition process, this paper focused on the correlation peak and acquisition probability. For the tracking process, this paper focused on the carrier tracking loop and the code tracking loop. Simulation results show that under high scintillation intensity, the phase fluctuation could be −1.13 ± 0.087 rad to 1.40 ± 0.087 rad and the relative amplitude fluctuation could be −10 dB to 8 dB. As the scintillation intensity increased, the average correlation peak would decrease more than 8%, which could thus degrade acquisition performance. On the other hand, when the signal-to-noise ratio (SNR) is comparatively lower, the influence of strong scintillation on the phase locked loop (PLL) is much higher than that of weak scintillation. As the scintillation becomes more intense, PLL variance could consequently results in an error of more than 2.02 cm in carrier-phase based ranging. In addition, the delay locked loop (DLL) simulation results indicated that the pseudo-range error caused by strong scintillation could be more than 4 m and the consequent impact on positioning accuracy could be more than 6 m. PMID:27834867

  4. Horizon Based Orientation Estimation for Planetary Surface Navigation

    NASA Technical Reports Server (NTRS)

    Bouyssounouse, X.; Nefian, A. V.; Deans, M.; Thomas, A.; Edwards, L.; Fong, T.

    2016-01-01

    Planetary rovers navigate in extreme environments for which a Global Positioning System (GPS) is unavailable, maps are restricted to relatively low resolution provided by orbital imagery, and compass information is often lacking due to weak or not existent magnetic fields. However, an accurate rover localization is particularly important to achieve the mission success by reaching the science targets, avoiding negative obstacles visible only in orbital maps, and maintaining good communication connections with ground. This paper describes a horizon solution for precise rover orientation estimation. The detected horizon in imagery provided by the on board navigation cameras is matched with the horizon rendered over the existing terrain model. The set of rotation parameters (roll, pitch yaw) that minimize the cost function between the two horizon curves corresponds to the rover estimated pose.

  5. Locks and Dam 1 (Ford Dam), Mississippi River, Draft Feasibility Report and Environmental Assessment for Hydropower.

    DTIC Science & Technology

    1984-08-01

    Mississippi River. 91 o In the event that the existing licensee, Ford Motor Company , or another non-Federal entity does not apply to FERC for rights to...interests. The existing hydropower plant and equipment are owned and operated by the Ford Motor Company . The existing four turbines generate a combined...Turbines (Ford Motor Company ) 51 Right (West) Abutment 51 Preliminary Screening of Alternatives 51 Conclusions of the Preliminary Comparative Review 53

  6. 14 CFR 91.511 - Communication and navigation equipment for overwater operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... high frequency communications is expected to exist. [Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Communication and navigation equipment for overwater operations. 91.511 Section 91.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...

  7. 14 CFR 91.511 - Communication and navigation equipment for overwater operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... high frequency communications is expected to exist. [Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Communication and navigation equipment for overwater operations. 91.511 Section 91.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...

  8. 14 CFR 91.511 - Communication and navigation equipment for overwater operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... high frequency communications is expected to exist. [Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Communication and navigation equipment for overwater operations. 91.511 Section 91.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...

  9. 14 CFR 91.511 - Communication and navigation equipment for overwater operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... high frequency communications is expected to exist. [Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Communication and navigation equipment for overwater operations. 91.511 Section 91.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...

  10. 14 CFR 91.511 - Communication and navigation equipment for overwater operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... high frequency communications is expected to exist. [Doc. No. 18334, 54 FR 34314, Aug. 18, 1989, as... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Communication and navigation equipment for overwater operations. 91.511 Section 91.511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION...

  11. 75 FR 28592 - Notice of Public Scoping Meetings for the Missouri River Authorized Purposes Study, Missouri...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ..., navigation, irrigation, power, water supply, water quality, recreation, and fish and wildlife. ADDRESSES..., navigation, irrigation, power, water supply, water quality, recreation, and fish and wildlife. Section 108 of... judicial rulings to determine if changes to the authorized project purposes and existing federal water...

  12. Real-time single-frequency GPS/MEMS-IMU attitude determination of lightweight UAVs.

    PubMed

    Eling, Christian; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-10-16

    In this paper, a newly-developed direct georeferencing system for the guidance, navigation and control of lightweight unmanned aerial vehicles (UAVs), having a weight limit of 5 kg and a size limit of 1.5 m, and for UAV-based surveying and remote sensing applications is presented. The system is intended to provide highly accurate positions and attitudes (better than 5 cm and 0.5°) in real time, using lightweight components. The main focus of this paper is on the attitude determination with the system. This attitude determination is based on an onboard single-frequency GPS baseline, MEMS (micro-electro-mechanical systems) inertial sensor readings, magnetic field observations and a 3D position measurement. All of this information is integrated in a sixteen-state error space Kalman filter. Special attention in the algorithm development is paid to the carrier phase ambiguity resolution of the single-frequency GPS baseline observations. We aim at a reliable and instantaneous ambiguity resolution, since the system is used in urban areas, where frequent losses of the GPS signal lock occur and the GPS measurement conditions are challenging. Flight tests and a comparison to a navigation-grade inertial navigation system illustrate the performance of the developed system in dynamic situations. Evaluations show that the accuracies of the system are 0.05° for the roll and the pitch angle and 0.2° for the yaw angle. The ambiguities of the single-frequency GPS baseline can be resolved instantaneously in more than 90% of the cases.

  13. Process, policy, and implementation of pool-wide drawdowns on the Upper Mississippi River: a promising approach for ecological restoration of large impounded rivers

    USGS Publications Warehouse

    Kenow, Kevin P.; Gretchen Benjamin,; Tim Schlagenhaft,; Ruth Nissen,; Mary Stefanski,; Gary Wege,; Scott A. Jutila,; Newton, Teresa J.

    2016-01-01

    The Upper Mississippi River (UMR) has been developed and subsequently managed for commercial navigation by the U.S. Army Corps of Engineers (USACE). The navigation pools created by a series of lock and dams initially provided a complex of aquatic habitats that supported a variety of fish and wildlife. However, biological productivity declined as the pools aged. The River Resources Forum, an advisory body to the St. Paul District of the USACE, established a multiagency Water Level Management Task Force (WLMTF) to evaluate the potential of water level management to improve ecological function and restore the distribution and abundance of fish and wildlife habitat. The WLMTF identified several water level management options and concluded that summer growing season drawdowns at the pool scale offered the greatest potential to provide habitat benefits over a large area. Here we summarize the process followed to plan and implement pool-wide drawdowns on the UMR, including involvement of stakeholders in decision making, addressing requirements to modify reservoir operating plans, development and evaluation of drawdown alternatives, pool selection, establishment of a monitoring plan, interagency coordination, and a public information campaign. Three pool-wide drawdowns were implemented within the St. Paul District and deemed successful in providing ecological benefits without adversely affecting commercial navigation and recreational use of the pools. Insights are provided based on more than 17 years of experience in planning and implementing drawdowns on the UMR. 

  14. Minimising harbour siltation—findings of PIANC Working Group 43

    NASA Astrophysics Data System (ADS)

    Kirby, Robert

    2011-03-01

    Modern trends, increases in ship size, improved cargo handling capability, sea level rise and erosion threats to low-lying land, undesirable attributes of certain traditional mud dredging and disposal practices, coupled with pressure from environmental legislation, are all driving a need to manage coastal waters and fine sediment in a more sophisticated manner. Wide-ranging review of world "best practice" has highlighted five fully evolved northwest European generic sediment management systems (SMS) to address these challenges. These are being applied to universally recurring types of port facilities: impounded docks, lock entrances, semi-enclosed basins, channels and fairways. They are applicable to large and small, existing and new facilities in rivers, estuaries, open sea coasts, even in some cases to lakes. They can be passive or active. The functioning of each of these five is explained with comment on economic benefit. What emerges strongly is that the applied academic disciplines of physical and chemical oceanography, plus marine microbiology, are being drawn together to supplement or replace traditional maritime engineering. Following on from a Permanent International Association of Navigation Congresses review, these technologies are spreading beyond the northwest European conception area, as well as beginning to be adopted by international dredging companies. The complexity, scale of potential benefit, numbers of poorly understood issues highlighted and embryonic way these are beginning to spread all suggest that this is potentially an important area for future scientific endeavour.

  15. Do large rate coefficients for ion-polar neutral reactions have a serious effect on chemical models of dense clouds?

    NASA Technical Reports Server (NTRS)

    Herbst, E.; Leung, C. M.

    1986-01-01

    In order to incorporate large ion-polar neutral rate coefficients into existing gas phase reaction networks, it is necessary to utilize simplified theoretical treatments because of the significant number of rate coefficients needed. The authors have used two simple theoretical treatments: the locked dipole approach of Moran and Hamill for linear polar neutrals and the trajectory scaling approach of Su and Chesnavich for nonlinear polar neutrals. The former approach is suitable for linear species because in the interstellar medium these are rotationally relaxed to a large extent and the incoming charged reactants can lock their dipoles into the lowest energy configuration. The latter approach is a better approximation for nonlinear neutral species, in which rotational relaxation is normally less severe and the incoming charged reactants are not as effective at locking the dipoles. The treatments are in reasonable agreement with more detailed long range theories and predict an inverse square root dependence on kinetic temperature for the rate coefficient. Compared with the locked dipole method, the trajectory scaling approach results in rate coefficients smaller by a factor of approximately 2.5.

  16. International Space Station (ISS) Airlock Crewlock Depressurization Methods

    NASA Technical Reports Server (NTRS)

    Williams, David E.; Leonard, Daniel J.; Booth, Valori J.; Russell, Matt

    2004-01-01

    The International Space Station (ISS) Airlock Crewlock can be depressurized via various methods. The ISS Airlock is divided into two major sections, the Equipment Lock and Crewlock. The Equipment Lock, as the name indicates, contains the equipment to support EVA activities including Extravehicular Maneuvering/Mobility Unit (EMU) maintenance and refurbishment. The Equipment Lock also contains basic life support equipment in order to support denitrogenzation protocols while the Airlock is isolated from the rest of the ISS. The Crewlock is the section of the Airlock that is depressurized to allow for Extravehicular Activity (EVA) crewmembers to exit the ISS for performance of EVAs. As opposed to the Equipment Lock, the Crewlock is quite simple and basically just contains lights and an assembly to provide services, oxygen, coolant, etc, to the EMUs. For operational flexibility, various methods were derived for Crewlock depressurization. Herein these various different methods of ISS Airlock Crewlock depressurization will be described including their performance, impacts, and risks associated with each method. Each of the different methods will be discussed with flight data, if it exists. Models will be applied to flight cases and to other methods that have not been used on-orbit at this time.

  17. Large-eddy-simulation approach in understanding flow structures of 2D turbulent density currents over sloping surfaces

    NASA Astrophysics Data System (ADS)

    Nayamatullah, M.; Rao Pillalamarri, Narasimha; Bhaganagar, Kiran

    2018-04-01

    A numerical investigation was performed to understand the flow dynamics of 2D density currents over sloping surfaces. Large eddy simulation was conducted for lock-exchange (L-E) release currents and overflows. 2D Navier-Stokes equations were solved using the Boussinesq approximation. The effects of the lock aspect-ratio (height/length of lock), slope, and Reynolds number on the flow structures and turbulence mixing have been analyzed. Results have confirmed buoyancy within the head of the two-dimensional currents is not conserved which contradicts the classical thermal theory. The lock aspect-ratio dictates the fraction of initial buoyancy which is carried by the head of the current at the beginning of the slumping (horizontal) and accelerating phase (over a slope), which has important implications on turbulence kinetic energy production, and hence mixing in the current. For L-E flows over a slope, increasing slope angle enhances the turbulence production. Increasing slope results in shear reversal within the density current resulting in shear-instabilities. Differences in turbulence production mechanisms and flow structures exist between the L-E and constant-flux release currents resulting in significant differences in the flow characteristics between different releases.

  18. Simulating the Liaison Navigation Concept in a Geo + Earth-Moon Halo Constellation

    NASA Technical Reports Server (NTRS)

    Fujimoto, K.; Leonard, J. M.; McGranaghan, R. M.; Parker, J. S.; Anderson, R. L.; Born, G. H.

    2012-01-01

    Linked Autonomous Interplanetary Satellite Orbit Navigation, or LiAISON, is a novel satellite navigation technique where relative radiometric measurements between two or more spacecraft in a constellation are processed to obtain the absolute state of all spacecraft. The method leverages the asymmetry of the gravity field that the constellation exists in. This paper takes a step forward in developing a high fidelity navigation simulation for the LiAISON concept in an Earth-Moon constellation. In particular, we aim to process two-way Doppler measurements between a satellite in GEO orbit and another in a halo orbit about the Earth-Moon L1 point.

  19. Alternative transitions between existing representations in multi-scale maps

    NASA Astrophysics Data System (ADS)

    Dumont, Marion; Touya, Guillaume; Duchêne, Cécile

    2018-05-01

    Map users may have issues to achieve multi-scale navigation tasks, as cartographic objects may have various representations across scales. We assume that adding intermediate representations could be one way to reduce the differences between existing representations, and to ease the transitions across scales. We consider an existing multiscale map on the scale range from 1 : 25k to 1 : 100k scales. Based on hypotheses about intermediate representations design, we build custom multi-scale maps with alternative transitions. We will conduct in a next future a user evaluation to compare the efficiency of these alternative maps for multi-scale navigation. This paper discusses the hypotheses and production process of these alternative maps.

  20. Development of a prototype real-time automated filter for operational deep space navigation

    NASA Technical Reports Server (NTRS)

    Masters, W. C.; Pollmeier, V. M.

    1994-01-01

    Operational deep space navigation has been in the past, and is currently, performed using systems whose architecture requires constant human supervision and intervention. A prototype for a system which allows relatively automated processing of radio metric data received in near real-time from NASA's Deep Space Network (DSN) without any redesign of the existing operational data flow has been developed. This system can allow for more rapid response as well as much reduced staffing to support mission navigation operations.

  1. Study on index system of GPS interference effect evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Zeng, Fangling; Zhao, Yuan; Zeng, Ruiqi

    2018-05-01

    Satellite navigation interference effect evaluation is the key technology to break through the research of Navigation countermeasure. To evaluate accurately the interference degree and Anti-jamming ability of GPS receiver, this text based on the existing research results of Navigation interference effect evaluation, build the index system of GPS receiver effectiveness evaluation from four levels of signal acquisition, tracking, demodulation and positioning/timing and establish the model for each index. These indexes can accurately and quantitatively describe the interference effect at all levels.

  2. A Functional Description of a Digital Flight Test System for Navigation and Guidance Research in the Terminal Area

    NASA Technical Reports Server (NTRS)

    Hegarty, D. M.

    1974-01-01

    A guidance, navigation, and control system, the Simulated Shuttle Flight Test System (SS-FTS), when interfaced with existing aircraft systems, provides a research facility for studying concepts for landing the space shuttle orbiter and conventional jet aircraft. The SS-FTS, which includes a general-purpose computer, performs all computations for precisely following a prescribed approach trajectory while properly managing the vehicle energy to allow safe arrival at the runway and landing within prescribed dispersions. The system contains hardware and software provisions for navigation with several combinations of possible navigation aids that have been suggested for the shuttle. The SS-FTS can be reconfigured to study different guidance and navigation concepts by changing only the computer software, and adapted to receive different radio navigation information through minimum hardware changes. All control laws, logic, and mode interlocks reside solely in the computer software.

  3. Portable microwave frequency dissemination in free space and implications on ground-to-satellite synchronization.

    PubMed

    Miao, J; Wang, B; Bai, Y; Yuan, Y B; Gao, C; Wang, L J

    2015-05-01

    Frequency dissemination and synchronization in free space play an important role in global navigation satellite system, radio astronomy, and synthetic aperture radar. In this paper, we demonstrated a portable radio frequency dissemination scheme via free space using microwave antennas. The setup has a good environment adaptability and high dissemination stability. The frequency signal was disseminated at different distances ranging from 10 to 640 m with a fixed 10 Hz locking bandwidth, and the scaling law of dissemination stability on distance and averaging time was discussed. The preliminary extrapolation shows that the dissemination stability may reach 1 × 10(-12)/s in ground-to-satellite synchronization, which far exceeds all present methods, and is worthy for further study.

  4. A Comprehensive Electronic Health Record Based Patient Navigation Module Including Technology Driven Colorectal Cancer Outreach and Education.

    PubMed

    Ajeesh, Sunny; Luis, Rustveld

    2018-06-01

    The purpose of this concept paper is to propose an innovative multifaceted patient navigation module embedded in the Electronic Health Record (EHR) to address barriers to efficient and effective colorectal cancer (CRC) care. The EHR-based CRC patient navigation module will include several patient navigation features: (1) CRC screening registry; (2) patient navigation data, including CRC screening data, outcomes of patient navigation including navigation status (CRC screening referrals, fecal occult blood test (FOBT) completed, colonoscopy scheduled and completed, cancelations, reschedules, and no-shows); (3) CRC counseling aid; and 4) Web-based CRC education application including interactive features such as a standardized colonoscopy preparation guide, modifiable CRC risk factors, and links to existing resources. An essential component of health informatics is the use of EHR systems to not only provide a system for storing and retrieval of patient health data but can also be used to enhance patient decision-making both from a provider and patient perspective.

  5. Polariton condensation, superradiance and difference combination parametric resonance in mode-locked laser

    NASA Astrophysics Data System (ADS)

    Bagayev, S. N.; Arkhipov, R. M.; Arkhipov, M. V.; Egorov, V. S.; Chekhonin, I. A.; Chekhonin, M. A.

    2017-11-01

    The generation of the ring mode-locked laser containing resonant absorption medium in the cavity was investigated. It is shown that near the strong resonant absorption lines a condensation of polaritons arises. Intensive radiation looks like as superradiance in a medium without population inversion. We studied theoretically the microscopic mechanism of these phenomena. It was shown that in this system in absorbing medium a strong self-induced difference combination parametric resonance exists. Superradiance on polaritonic modes in the absorbing medium are due to the emergence of light-induced resonant polarization as a result of fast periodic nonadiabatic quantum jumps in the absorber.

  6. Demodulation signal processing in multiphoton imaging

    NASA Astrophysics Data System (ADS)

    Fisher, Walter G.; Wachter, Eric A.; Piston, David W.

    2002-06-01

    Multiphoton laser scanning microscopy offers numerous advantages, but sensitivity can be seriously affected by contamination from ambient room light. Typically, this forces experiments to be performed in an absolutely dark room. Since mode-locked lasers are used to generate detectable signals, signal-processing can be used to avoid such problems by taking advantage of the pulsed characteristics of such lasers. Demodulation of the fluorescence signal generated at the mode-locked frequency can result in significant reduction of interference from ambient noise sources. Such demodulation can be readily adapted to existing microscopes by inserting appropriate processor circuitry between the detector and data collection system, yielding a more robust microscope.

  7. How Do (Some) People Make a Cognitive Map? Routes, Places, and Working Memory

    ERIC Educational Resources Information Center

    Weisberg, Steven M.; Newcombe, Nora S.

    2016-01-01

    Research on the existence of cognitive maps and on the cognitive processes that support effective navigation has often focused on functioning across individuals. However, there are pronounced individual differences in navigation proficiency, which need to be explained and which can illuminate our understanding of cognitive maps and effective…

  8. 33 CFR 165.1325 - Regulated Navigation Areas; Bars Along the Coasts of Oregon and Washington.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., wave period, and tidal currents. When a bar is restricted, the operation of recreational and... passengers. (13) Unsafe condition exists when the wave height within a regulated navigation area identified in paragraph (a) of this section is equal to or greater than the maximum wave height determined by...

  9. Taux: A System for Evaluating Sound Feedback in Navigational Tasks

    ERIC Educational Resources Information Center

    Lutz, Robert J.

    2008-01-01

    This thesis presents the design and development of an evaluation system for generating audio displays that provide feedback to persons performing navigation tasks. It first develops the need for such a system by describing existing wayfinding solutions, investigating new electronic location-based methods that have the potential of changing these…

  10. 77 FR 65461 - Amendment of Area Navigation Route Q-1; CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ... existing ENVIE, CA, and EBINY, OR, waypoints for traffic flow metering with the Oakland Air Route Traffic... FAA is adding two waypoints along to route for air traffic control purposes. In addition, the route... is a routine matter that will only affect air traffic procedures and air navigation, it is certified...

  11. Novel All Digital Ring Cavity Locking Servo

    NASA Astrophysics Data System (ADS)

    Baker, J.; Gallant, D.; Lucero, A.; Miller, H.; Stohs, J.

    We plan to use this servo in the new 50W 589-nm sodium guidestar laser to be installed in the AMOS facility in July 2010. Though the basic design is unchanged from the successful Hillman/Denman design, numerous improvements are being implemented in order to bring the device even further out of the lab and into the field. The basic building block of the Hillman/Denman design are two low noise master oscillators that are injected into higher power slave oscillators that are locked to the frequencies of the master oscillator cavities. In the previous system a traditional analog Pound-Drever-Hall (PDH) loop was employed to provide the frequency locking. Analog servos work well, in general, but robust locking for a complex set of multiply-interconnected PDH servos in the guidestar source challenges existing analog approaches. One of the significant changes demonstrated thus far is the implementation of an all-digital servo using only COTS components and a fast CISC processing architecture for orchestrating the basic PDH loops active within system. Compared to the traditionally used analog servo loops, an all-digital servo is a not only an orders-of-magnitude simpler servo loop to implement but the control loop can be modified by merely changing the computer code. Field conditions are often different from laboratory conditions, requiring subtle algorithm changes, and physical accessibility in the field is generally limited and difficult. Remotely implemented, trimmer-less and solderless servo upgrades are a much welcomed improvement in the field installed guidestar system. Also, OEM replacement of usual benchtop components saves considerable space and weight as well in the locking system. We will report on the details of the servo system and recent experimental results locking a master-slave laser oscillator system using the all-digital Pound-Drever-Hall loop.

  12. Slip rates and spatially variable creep on faults of the northern San Andreas system inferred through Bayesian inversion of Global Positioning System data

    USGS Publications Warehouse

    Murray, Jessica R.; Minson, Sarah E.; Svarc, Jerry L.

    2014-01-01

    Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic creep rate above the locking depth. We estimate deep slip rates of 21.5 ± 0.5, 13.1 ± 0.8, and 7.5 ± 0.7 mm/yr below 16 km, 9 km, and 13 km on the San Andreas, Maacama, and Bartlett Springs Faults, respectively. We infer that on average the Bartlett Springs fault creeps from the Earth's surface to 13 km depth, and below 5 km the creep rate approaches the deep slip rate. This implies that microseismicity may extend below the locking depth; however, we cannot rule out the presence of locked patches in the seismogenic zone that could generate moderate earthquakes. Our estimated Maacama creep rate, while comparable to the inferred deep slip rate at the Earth's surface, decreases with depth, implying a slip deficit exists. The Maacama deep slip rate estimate, 13.1 mm/yr, exceeds long-term geologic slip rate estimates, perhaps due to distributed off-fault strain or the presence of multiple active fault strands. While our creep rate estimates are relatively insensitive to choice of model locking depth, insufficient independent information regarding locking depths is a source of epistemic uncertainty that impacts deep slip rate estimates.

  13. Block modeling of crustal deformation in Tierra del Fuego from GNSS velocities

    NASA Astrophysics Data System (ADS)

    Mendoza, L.; Richter, A.; Fritsche, M.; Hormaechea, J. L.; Perdomo, R.; Dietrich, R.

    2015-05-01

    The Tierra del Fuego (TDF) main island is divided by a major transform boundary between the South America and Scotia tectonic plates. Using a block model, we infer slip rates, locking depths and inclinations of active faults in TDF from inversion of site velocities derived from Global Navigation Satellite System observations. We use interseismic velocities from 48 sites, obtained from field measurements spanning 20 years. Euler vectors consistent with a simple seismic cycle are estimated for each block. In addition, we introduce far-field information into the modeling by applying constraints on Euler vectors of major tectonic plates. The difference between model and observed surface deformation near the Magallanes Fagnano Fault System (MFS) is reduced by considering finite dip in the forward model. For this tectonic boundary global plate circuits models predict relative movements between 7 and 9 mm yr- 1, while our regional model indicates that a strike-slip rate of 5.9 ± 0.2 mm yr- 1 is accommodated across the MFS. Our results indicate faults dipping 66- 4+ 6° southward, locked to a depth of 11- 5+ 5 km, which are consistent with geological models for the MFS. However, normal slip also dominates the fault perpendicular motion throughout the eastern MFS, with a maximum rate along the Fagnano Lake.

  14. Techniques for computing discharge at four Navigation Dams on the Illinois and Des Plaines Rivers in Illinois

    USGS Publications Warehouse

    Mades, Dean M.; Weiss, Linda S.; Gray, John R.

    1991-01-01

    Techniques for computing discharge are developed for Brandon Road Dam on the Des Plaines River and for Dresden Island, Marseilles, and Starved Rock Dams on the Illinois River. At Brandon Road Dam, streamflow is regulated by the operation of Tainter gates and headgates. At Dresden Island, Marseilles, and Starved Rock Dams, only Tainter gates are operated to regulate streamflow. The locks at all dams are equipped with culvert valves that are used to fill and empty the lock. The techniques facilitate determination of discharge at locations along the upper Illinois Waterway where no streamflow-gaging stations exist. The techniques are also useful for computing low flows when the water-surface slope between control structures on the river approaches zero and traditional methods of determining discharge based on slope are unsatisfactory. Two techniques can be used to compute discharge at the dams--gate ratings and tailwater ratings . A gate ratingdescribes the relation between discharge, gate opening, tailwater stage, and headwater stage. A tailwater rating describes the relation between tailwater stage and discharge. Gate ratings for Tainter gates at Dresden Island, Marseilles, and Starved Rock Dams are based on a total of 78 measurements of discharge that range from 569 to 86,400 cubic feet per second. Flood hydrographs developed from the gate ratings and Lockmaster records of gate opening and stage compare closely with streamflow records published for nearby streamflow-gaging stations. Additional measurements are needed to verify gate ratings for Tainter gates and headgates at Brandon Road Dam after the dam rehabilitation is completed. Extensive leakage past deteriorated headgates and sluice gates contributed to uncertainty in the ratings developed for this dam. A useful tailwater rating is developed for Marseilles Dam. Tailwater ratings for Dresden Island Dam and Starved Rock Dam are of limited use because of varying downstream channel-storage conditions. A tailwater rating could not be developed for Brandon Road Dam because its tailwater pool is substantially affected by the headwater pool of Dresden Island Dam.

  15. Plans for a Northern Cascadia Subduction Zone Observatory

    NASA Astrophysics Data System (ADS)

    Heesemann, M.; Wang, K.; Davis, E.; Chadwell, C. D.; Nissen, E.; Moran, K.; Scherwath, M.

    2017-12-01

    To accurately assess earthquake and tsunami hazards posed by the Cascadia Subduction Zone, it is critically important to know which area of the plate interface is locked and whether or not part of the energy is being released aseismically by slow creep on the fault. Deeper locking that extends further to the coast produces stronger shaking in population centers. Shallow locking, on the other hand, leads to bigger tsunamis. We will report on and discuss plans for a new amphibious Northern Cascadia Subduction Zone Observatory (NCSZO) that will leverage the existing NEPTUNE cabled seafloor observatory, which is operated by Ocean Networks Canada (ONC), and the onshore network of geodetic stations, which is operated by Natural Resources Canada (NRCan). To create a NCSZO we plan to (1) add a network of seven GPS-Acoustic (GPS-A) sites offshore Vancouver Island, (2) establish a Deformation Front Observatory, and (3) improve the existing onshore geodetic network (see Figure below). The GPS-A stations will provide the undisturbed motion of the Juan de Fuca (JdF) Plate (1), deformation of the JdF plate (2), deformation of the overriding plate (3-7) and a cabled laboratory to study the potential for continuous GPS-A measurements (6). The Deformation Front Observatory will be used to study possible transient slip events using seafloor pressure and tilt instruments and fluid flux meters.

  16. Qualitative analysis of ultra-short optical dissipative solitary pulses in the actively mode-locked semiconductor heterolasers with an external fiber cavity

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Alexandre S.; Campos Acosta, Joaquin; Moreno Zarate, Pedro; Pons Aglio, Alicia

    2011-02-01

    An advanced qualitative characterization of simultaneously existing various low-power trains of ultra-short optical pulses with an internal frequency modulation in a distributed laser system based on semiconductor heterostructure is presented. The scheme represents a hybrid cavity consisting of a single-mode heterolaser operating in the active mode-locking regime and an external long single-mode optical fiber exhibiting square-law dispersion, cubic Kerr nonlinearity, and linear optical losses. In fact, we consider the trains of optical dissipative solitons, which appear within double balance between the second-order dispersion and cubic-law nonlinearity as well as between the active-medium gain and linear optical losses in a hybrid cavity. Moreover, we operate on specially designed modulating signals providing non-conventional composite regimes of simultaneous multi-pulse active mode-locking. As a result, the mode-locking process allows shaping regular trains of picosecond optical pulses excited by multi-pulse independent on each other sequences of periodic modulations. In so doing, we consider the arranged hybrid cavity as a combination of a quasi-linear part responsible for the active mode-locking by itself and a nonlinear part determining the regime of dissipative soliton propagation. Initially, these parts are analyzed individually, and then the primarily obtained data are coordinated with each other. Within this approach, a contribution of the appeared cubically nonlinear Ginzburg-Landau operator is analyzed via exploiting an approximate variational procedure involving the technique of trial functions.

  17. Saint Lawrence Seaway Additional Locks Study. Appendices.

    DTIC Science & Technology

    1982-07-01

    agricultural development. Virgin forests still exist, but to a significantly lesser degree in the north woods country of Michigan, Wisconsin, and northern...was for agricultural use, but by the last half of the 19th century, increased development of lumbering and other wood -using industries took place. By...potentially adversely affect the natural ecological system of the river (reference Effects to the Natural Environment Section), and in turn, the existing

  18. Attitudes on Technological, Social, and Behavioral Economic Strategies to Reduce Cellphone Use While Driving in Teens.

    PubMed

    Delgado, M Kit; McDonald, Catherine C; Winston, Flaura K; Halpern, Scott D; Buttenheim, Alison M; Setubal, Claudia; Huang, Yanlan; Saulsgiver, Kathryn A; Lee, Yi-Ching

    2018-04-13

    The majority of U.S. teens admit to handheld cellphone use while driving, an increasingly common cause of crashes. Attitudes towards novel cellphone applications and settings that block use while driving are poorly understood, potentially limiting uptake. We examined teens' willingness to reduce cellphone use while driving and perceptions of potential strategies to limit this behavior. Teen drivers (n = 153) aged 16-17 who owned smartphones and admitted to texting while driving completed an online survey. Survey instruments measured willingness to give up cellphone use and perceptions of technological and behavioral economic strategies to reduce cellphone use while driving. We used Chi-square tests to test the hypothesis that willingness to give up certain types of cellphone use while driving and the perceptions of strategies to reduce cellphone use while driving would differ by self-reported frequency of texting while driving in the past 30 days (low [1-5 days] vs. high [6 or more days]. Most teens were willing or somewhat willing to give up reading texts (90%), sending texts (95%), and social media (99%) while driving. However they were not willing to give up navigation (59%) and music applications (43%). Those who engaged in high-frequency texting while driving were more likely to say they were not willing to give up navigation applications (73% vs. 44%, P <0.001), music applications (54% vs. 32%, P <0.001), and reading texts (15% vs. 4%) (P = 0.029). Overall, the following strategies where rated as likely to be "very effective" for reducing texting while driving: gain-framed financial incentives (75%), loss-framed financial incentives (63%), group-based financial incentives (58%), insurance discounts (53%), automatic phone locking while driving (54%), email notifications to parents (47%), automated responses to incoming texts (42%), peer concern (18%), and parental concern (15%). Those who engaged in high-frequency texting while driving were less likely to say that following strategies would be very effective: automated responses to incoming texts (33% vs. 53%, P = 0.016), peer concern (9% vs. 29%, P = 0.002), and parental concern (9% vs. 22%, P = 0.025). The strongest perceived benefit of cellphone blocking apps was decreasing distraction (86%). The predominant reason for not wanting to use this technology was not wanting parents to monitor their behavior (60%). Promising strategies for increasing acceptance of cellphone blocking technology among teen drivers include automated screen locking and permitting hands-free navigation and music combined with behavioral economic incentives to sustain engagement.

  19. Valley-controlled propagation of pseudospin states in bulk metacrystal waveguides

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Dong; Deng, Wei-Min; Lu, Jin-Cheng; Dong, Jian-Wen

    2018-05-01

    Light manipulations such as spin-direction locking propagation, robust transport, quantum teleportation, and reconfigurable electromagnetic pathways have been investigated at the boundaries of photonic systems. Recently by breaking Dirac cones in time-reversal-invariant photonic crystals, valley-pseudospin coupled edge states have been employed to realize selective propagation of light. Here, we realize the controllable propagation of pseudospin states in three-dimensional bulk metacrystal waveguides by valley degree of freedom. Reconfigurable photonic valley Hall effect is achieved for frequency-direction locking propagation in such a way that the propagation path can be tunable precisely by scanning the working frequency. A complete transition diagram is illustrated on the valley-dependent pseudospin states of Dirac-cone-absent photonic bands. A photonic blocker is proposed by cascading two inversion asymmetric metacrystal waveguides in which pseudospin-direction locking propagation exists. In addition, valley-dependent pseudospin bands are also discussed in a realistic metamaterials sample. These results show an alternative way toward molding the pseudospin flow in photonic systems.

  20. Experimental examination of frequency locking effect in acousto-optic system

    NASA Astrophysics Data System (ADS)

    Mantsevich, S. N.; Balakshy, V. I.

    2018-04-01

    The optoelectronic system containing collinear acousto-optic cell fabricated on the base of calcium molybdate crystal and positive electronic feedback circuit was examined. The feedback signal is formed due to the optical heterodyning effect that occurs on the cell output and takes place in the special regime of collinear acousto-optic diffraction. It was discovered that three operation modes that may exist in this system. The boundaries between the modes were determined. The positions of the boundaries depend on the main parameters of the system—the incident light intensity and the feedback gain value. The new for acousto-optics phenomenon of acousto-optic system self-oscillations frequency locking by the RF generator signal was discovered and examined experimentally. Such an effect has never been observed before in the acousto-optic systems. It was experimentally shown that frequency locking effect may be used to select one of the multimode semiconductor laser longitudinal modes to improve laser radiation spectral composition.

  1. Selection of radio sources for Venus balloon-Pathfinder Delta-DOR navigation at 1.7 GHz

    NASA Technical Reports Server (NTRS)

    Liewer, K. M

    1986-01-01

    In order to increase the success rate of the Delta-DOR (Delta-Differential One-way Range) VLBI navigational support for the French-Soviet Venus Balloon and Halley Pathfinder projects, forty-four extragalactic radio sources were observed in advance of these projects to determine which were suitable for use as reference sources. Of these forty-four radio sources taken from the existing JPL radio source catalogue, thirty-six were determined to be of sufficient strength for use in Delta-DOR VLBI navigation.

  2. 78 FR 29336 - Intent To Prepare an Environmental Impact Statement for Arctic Deep Draft Ports Navigation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... vicinity of Nome is not adequate to accommodate the need for an efficient and safe harbor appropriate to... Transportation is working with the U. S. Army Corps of Engineers in investigating the need for expanding the... encounter the haphazard navigation scenario that presently exists in a challenging maritime environment...

  3. 33 CFR 329.10 - Existence of obstructions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DEFENSE DEFINITION OF NAVIGABLE WATERS OF THE UNITED STATES § 329.10 Existence of obstructions. A stream... obstruction by means of artificial chutes. However, the question is ultimately a matter of degree, and it must...

  4. Metrics for evaluating patient navigation during cancer diagnosis and treatment: crafting a policy-relevant research agenda for patient navigation in cancer care.

    PubMed

    Guadagnolo, B Ashleigh; Dohan, Daniel; Raich, Peter

    2011-08-01

    Racial and ethnic minorities as well as other vulnerable populations experience disparate cancer-related health outcomes. Patient navigation is an emerging health care delivery innovation that offers promise in improving quality of cancer care delivery to these patients who experience unique health-access barriers. Metrics are needed to evaluate whether patient navigation can improve quality of care delivery, health outcomes, and overall value in health care during diagnosis and treatment of cancer. Information regarding the current state of the science examining patient navigation interventions was gathered via search of the published scientific literature. A focus group of providers, patient navigators, and health-policy experts was convened as part of the Patient Navigation Leadership Summit sponsored by the American Cancer Society. Key metrics were identified for assessing the efficacy of patient navigation in cancer diagnosis and treatment. Patient navigation data exist for all stages of cancer care; however, the literature is more robust for its implementation during prevention, screening, and early diagnostic workup of cancer. Relatively fewer data are reported for outcomes and efficacy of patient navigation during cancer treatment. Metrics are proposed for a policy-relevant research agenda to evaluate the efficacy of patient navigation in cancer diagnosis and treatment. Patient navigation is understudied with respect to its use in cancer diagnosis and treatment. Core metrics are defined to evaluate its efficacy in improving outcomes and mitigating health-access barriers. Copyright © 2011 American Cancer Society.

  5. Metrics for evaluating patient navigation during cancer diagnosis and treatment: crafting a policy-relevant research agenda for patient navigation in cancer care

    PubMed Central

    Guadagnolo, B. Ashleigh; Dohan, Daniel; Raich, Peter

    2016-01-01

    Background Racial and ethnic minorities as well as other vulnerable populations experience disparate cancer-related health outcomes. Patient navigation is an emerging health care delivery innovation that offers promise in improving quality of cancer care delivery to these patients who experience unique health access barriers. Metrics are needed to evaluate whether patient navigation can improve quality of care delivery, health outcomes, and overall value in health care during diagnosis and treatment of cancer. Methods Information regarding the current state of the science examining patient navigation interventions was gathered via search of the published scientific literature. A focus group of providers, patient navigators, and health policy experts was convened as part of the Patient Navigation Leadership Summit sponsored by the American Cancer Society. Key metrics were identified for assessing the efficacy of patient navigation in cancer diagnosis and treatment. Results Patient navigation data exists for all stages of cancer care; however, the literature is more robust for its implementation during prevention, screening, and early diagnostic work-up of cancer. Relatively fewer data are reported for outcomes and efficacy of patient navigation during cancer treatment. Metrics are proposed for a policy-relevant research agenda to evaluate the efficacy of patient navigation in cancer diagnosis and treatment. Conclusions Patient navigation is understudied with respect to its use in cancer diagnosis and treatment. Core metrics are defined to evaluate its efficacy in improving outcomes and mitigating health access barriers. PMID:21780091

  6. 77 FR 30926 - Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-24

    ... Division Turbofan Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... turbofan engines. The existing AD currently requires initial and repetitive fluorescent penetrant... turbofan engines. That AD requires initial and repetitive FPI for cracks in the blade locking and loading...

  7. X-Ray Detection and Processing Models for Spacecraft Navigation and Timing

    NASA Technical Reports Server (NTRS)

    Sheikh, Suneel; Hanson, John

    2013-01-01

    The current primary method of deepspace navigation is the NASA Deep Space Network (DSN). High-performance navigation is achieved using Delta Differential One-Way Range techniques that utilize simultaneous observations from multiple DSN sites, and incorporate observations of quasars near the line-of-sight to a spacecraft in order to improve the range and angle measurement accuracies. Over the past four decades, x-ray astronomers have identified a number of xray pulsars with pulsed emissions having stabilities comparable to atomic clocks. The x-ray pulsar-based navigation and time determination (XNAV) system uses phase measurements from these sources to establish autonomously the position of the detector, and thus the spacecraft, relative to a known reference frame, much as the Global Positioning System (GPS) uses phase measurements from radio signals from several satellites to establish the position of the user relative to an Earth-centered fixed frame of reference. While a GPS receiver uses an antenna to detect the radio signals, XNAV uses a detector array to capture the individual xray photons from the x-ray pulsars. The navigation solution relies on detailed xray source models, signal processing, navigation and timing algorithms, and analytical tools that form the basis of an autonomous XNAV system. Through previous XNAV development efforts, some techniques have been established to utilize a pulsar pulse time-of-arrival (TOA) measurement to correct a position estimate. One well-studied approach, based upon Kalman filter methods, optimally adjusts a dynamic orbit propagation solution based upon the offset in measured and predicted pulse TOA. In this delta position estimator scheme, previously estimated values of spacecraft position and velocity are utilized from an onboard orbit propagator. Using these estimated values, the detected arrival times at the spacecraft of pulses from a pulsar are compared to the predicted arrival times defined by the pulsar s pulse timing model. A discrepancy provides an estimate of the spacecraft position offset, since an error in position will relate to the measured time offset of a pulse along the line of sight to the pulsar. XNAV researchers have been developing additional enhanced approaches to process the photon TOAs to arrive at an estimate of spacecraft position, including those using maximum-likelihood estimation, digital phase locked loops, and "single photon processing" schemes that utilize all available time data associated with each photon. Using pulsars from separate, non-coplanar locations provides range and range-rate measurements in each pulsar s direction. Combining these different pulsar measurements solves for offsets in position and velocity in three dimensions, and provides accurate overall navigation for deep space vehicles.

  8. On families of differential equations on two-torus with all phase-lock areas

    NASA Astrophysics Data System (ADS)

    Glutsyuk, Alexey; Rybnikov, Leonid

    2017-01-01

    We consider two-parametric families of non-autonomous ordinary differential equations on the two-torus with coordinates (x, t) of the type \\overset{\\centerdot}{{x}} =v(x)+A+Bf(t) . We study its rotation number as a function of the parameters (A, B). The phase-lock areas are those level sets of the rotation number function ρ =ρ (A,B) that have non-empty interiors. Buchstaber, Karpov and Tertychnyi studied the case when v(x)=\\sin x in their joint paper. They observed the quantization effect: for every smooth periodic function f(t) the family of equations may have phase-lock areas only for integer rotation numbers. Another proof of this quantization statement was later obtained in a joint paper by Ilyashenko, Filimonov and Ryzhov. This implies a similar quantization effect for every v(x)=a\\sin (mx)+b\\cos (mx)+c and rotation numbers that are multiples of \\frac{1}{m} . We show that for every other analytic vector field v(x) (i.e. having at least two Fourier harmonics with non-zero non-opposite degrees and nonzero coefficients) there exists an analytic periodic function f(t) such that the corresponding family of equations has phase-lock areas for all the rational values of the rotation number.

  9. Stereotaxy, navigation and the temporal concatenation.

    PubMed

    Apuzzo, M L; Chen, J C

    1999-01-01

    Nautical and cerebral navigation share similar elements of functional need and similar developmental pathways. The need for orientation necessitates the development of appropriate concepts, and such concepts are dependent on technology for practical realization. Occasionally, a concept precedes technology in time and requires periods of delay for appropriate development. A temporal concatenation exists where time allows the additive as need, concept and technology ultimately provide an endpoint of elegant solution. Nautical navigation has proceeded through periods of dead reckoning and celestial navigation to satellite orientation with associated refinements of instrumentation and charts for guidance. Cerebral navigation has progressed from craniometric orientation and burr hole mounted guidance systems to simple rectolinear and arc-centered devices based on radiographs to guidance by complex anatomical and functional maps provided as an amalgam of modern imaging modes. These maps are now augmented by complex frame and frameless systems which allow not only precise orientation, but also point and volumetric action. These complex technical modalities required and developed in part from elements of maritime navigation that have been translated to cerebral navigation in a temporal concatenation. Copyright 2000 S. Karger AG, Basel

  10. The Development of a Simulator System and Hardware Test Bed for Deep Space X-Ray Navigation

    NASA Astrophysics Data System (ADS)

    Doyle, Patrick T.

    2013-03-01

    Currently, there is a considerable interest in developing technologies that will allow using photon measurements from celestial x-ray sources for deep space navigation. The impetus for this is that many envisioned future space missions will require spacecraft to have autonomous navigation capabilities. For missions close to Earth, Global Navigation Satellite Systems (GNSS) such as GPS are readily available for use, but for missions far from Earth, other alternatives must be provided. While existing systems such as the Deep Space Network (DSN) can be used, latencies associated with servicing a fleet of vehicles may not be compatible with some autonomous operations requiring timely updates of their navigation solution. Because of their somewhat predictable emissions, pulsars are the ideal candidates for x-ray sources that can be used to provide key parameters for navigation. Algorithms and simulation tools that will enable designing and analyzing x-ray navigation concepts are presented. The development of a compact x-ray detector system is pivotal to the eventual deployment of such navigation systems. Therefore, results of a high altitude balloon test to evaluate the design of a compact x-ray detector system are described as well.

  11. Space Shuttle Navigation in the GPS Era

    NASA Technical Reports Server (NTRS)

    Goodman, John L.

    2001-01-01

    The Space Shuttle navigation architecture was originally designed in the 1970s. A variety of on-board and ground based navigation sensors and computers are used during the ascent, orbit coast, rendezvous, (including proximity operations and docking) and entry flight phases. With the advent of GPS navigation and tightly coupled GPS/INS Units employing strapdown sensors, opportunities to improve and streamline the Shuttle navigation process are being pursued. These improvements can potentially result in increased safety, reliability, and cost savings in maintenance through the replacement of older technologies and elimination of ground support systems (such as Tactical Air Control and Navigation (TACAN), Microwave Landing System (MLS) and ground radar). Selection and missionization of "off the shelf" GPS and GPS/INS units pose a unique challenge since the units in question were not originally designed for the Space Shuttle application. Various options for integrating GPS and GPS/INS units with the existing orbiter avionics system were considered in light of budget constraints, software quality concerns, and schedule limitations. An overview of Shuttle navigation methodology from 1981 to the present is given, along with how GPS and GPS/INS technology will change, or not change, the way Space Shuttle navigation is performed in the 21 5 century.

  12. Real-Time Single-Frequency GPS/MEMS-IMU Attitude Determination of Lightweight UAVs

    PubMed Central

    Eling, Christian; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-01-01

    In this paper, a newly-developed direct georeferencing system for the guidance, navigation and control of lightweight unmanned aerial vehicles (UAVs), having a weight limit of 5 kg and a size limit of 1.5 m, and for UAV-based surveying and remote sensing applications is presented. The system is intended to provide highly accurate positions and attitudes (better than 5 cm and 0.5∘) in real time, using lightweight components. The main focus of this paper is on the attitude determination with the system. This attitude determination is based on an onboard single-frequency GPS baseline, MEMS (micro-electro-mechanical systems) inertial sensor readings, magnetic field observations and a 3D position measurement. All of this information is integrated in a sixteen-state error space Kalman filter. Special attention in the algorithm development is paid to the carrier phase ambiguity resolution of the single-frequency GPS baseline observations. We aim at a reliable and instantaneous ambiguity resolution, since the system is used in urban areas, where frequent losses of the GPS signal lock occur and the GPS measurement conditions are challenging. Flight tests and a comparison to a navigation-grade inertial navigation system illustrate the performance of the developed system in dynamic situations. Evaluations show that the accuracies of the system are 0.05∘ for the roll and the pitch angle and 0.2∘ for the yaw angle. The ambiguities of the single-frequency GPS baseline can be resolved instantaneously in more than 90% of the cases. PMID:26501281

  13. Challenges to replicating evidence-based research in real-world settings: training African-American peers as patient navigators for colon cancer screening.

    PubMed

    Sly, Jamilia R; Jandorf, Lina; Dhulkifl, Rayhana; Hall, Diana; Edwards, Tiffany; Goodman, Adam J; Maysonet, Elithea; Azeez, Sulaiman

    2012-12-01

    Many cancer-prevention interventions have demonstrated effectiveness in diverse populations, but these evidenced-based findings slowly disseminate into practice. The current study describes the process of disseminating and replicating research (i.e., peer patient navigation for colonoscopy screening) in real-world settings. Two large metropolitan hospitals collaborated to replicate a peer patient navigation model within their existing navigation systems. Six African-American peer volunteers were recruited and trained to navigate patients through colonoscopy scheduling and completion. Major challenges included: (1) operating within multiple institutional settings; (2) operating within nonacademic/research infrastructures; (3) integrating into an established navigation system; (4) obtaining support of hospital staff without overburdening; and (5) competing priorities and time commitments. Bridging the gap between evidence-based research and practice is critical to eliminating many cancer health disparities; therefore, it is crucial that researchers and practitioners continue to work to achieve both diffusion and fusion of evidence-based findings. Recommendations for addressing these challenges are discussed.

  14. 76 FR 26606 - Drawbridge Operation Regulation; Illinois Waterway, Near Morris, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-09

    ... allow removal of the existing lift span and installation of the replacement lift span. This deviation...-navigation position for eighty-four hours while the existing lift span is removed and the replacement lift...

  15. DEMONSTRATION OF AUTONOMOUS AIR MONITORING THROUGH ROBOTICS

    EPA Science Inventory

    This project included modifying an existing teleoperated robot to include autonomous navigation, large object avoidance, and air monitoring and demonstrating that prototype robot system in indoor and outdoor environments. An existing teleoperated "Surveyor" robot developed by ARD...

  16. A clock steering method: using a third-order type 3 DPLL equivalent to a Kalman filter with a delay

    NASA Astrophysics Data System (ADS)

    Wu, Yiwei; Gong, Hang; Zhu, Xiangwei; Ou, Gang

    2015-12-01

    In this paper we propose a new clock steering method, which uses a third-order type 3 digital phase locked loop (DPLL) which is equivalent to a Kalman filter with a delay. A general overview of the theoretical framework is described in detail including the transfer functions, the structure and control values, the specifications, and the approach to choosing a parameter. Simulations show that the performance of the time and frequency steering errors and the frequency stability are quite desirable. Comparing with traditional clock steering methods, it is easier to work with just one parameter. The DPLL method satisfies the requirements of generating a local representation of universal time coordinated and the system time of a global navigation satellite system.

  17. A demonstration of the value of spacecraft computers

    NASA Astrophysics Data System (ADS)

    Jenkins, R. E.

    1984-09-01

    The Transit Improvement Program TIP satellites were designed to upgrade the navigation satellite system. One of the improvements made in connection with these satellites is related to the employment of a general-purpose minicomputer. A description is provided of the uses of the TIP/Nova flight computer to overcome some early failures in the spacecraft development which, although later corrected, could have jeopardized the entire program. The flight computer and its software is discussed, taking into account the delayed command program, and the telemetry storage program. The effect of the failures is considered along with the post-launch operations. Attention is given to power management, spin-up operations, the firing of the orbit adjust rocket, the tumble-thrust program, a digital phase-locked loop for de-tumble, and the generation of a tumble motion.

  18. 33 CFR 165.768 - Security Zone; MacDill Air Force Base, Tampa Bay, FL.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; MacDill Air Force....768 Security Zone; MacDill Air Force Base, Tampa Bay, FL. (a) Location. The following area is a security zone which exists concurrent with an Army Corps of Engineers restricted area in § 334.635 of this...

  19. 33 CFR 165.768 - Security Zone; MacDill Air Force Base, Tampa Bay, FL.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; MacDill Air Force....768 Security Zone; MacDill Air Force Base, Tampa Bay, FL. (a) Location. The following area is a security zone which exists concurrent with an Army Corps of Engineers restricted area in § 334.635 of this...

  20. 33 CFR 165.768 - Security Zone; MacDill Air Force Base, Tampa Bay, FL.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; MacDill Air Force....768 Security Zone; MacDill Air Force Base, Tampa Bay, FL. (a) Location. The following area is a security zone which exists concurrent with an Army Corps of Engineers restricted area in § 334.635 of this...

  1. 33 CFR 165.768 - Security Zone; MacDill Air Force Base, Tampa Bay, FL.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; MacDill Air Force....768 Security Zone; MacDill Air Force Base, Tampa Bay, FL. (a) Location. The following area is a security zone which exists concurrent with an Army Corps of Engineers restricted area in § 334.635 of this...

  2. A method for evaluating discoverability and navigability of recommendation algorithms.

    PubMed

    Lamprecht, Daniel; Strohmaier, Markus; Helic, Denis

    2017-01-01

    Recommendations are increasingly used to support and enable discovery, browsing, and exploration of items. This is especially true for entertainment platforms such as Netflix or YouTube, where frequently, no clear categorization of items exists. Yet, the suitability of a recommendation algorithm to support these use cases cannot be comprehensively evaluated by any recommendation evaluation measures proposed so far. In this paper, we propose a method to expand the repertoire of existing recommendation evaluation techniques with a method to evaluate the discoverability and navigability of recommendation algorithms. The proposed method tackles this by means of first evaluating the discoverability of recommendation algorithms by investigating structural properties of the resulting recommender systems in terms of bow tie structure, and path lengths. Second, the method evaluates navigability by simulating three different models of information seeking scenarios and measuring the success rates. We show the feasibility of our method by applying it to four non-personalized recommendation algorithms on three data sets and also illustrate its applicability to personalized algorithms. Our work expands the arsenal of evaluation techniques for recommendation algorithms, extends from a one-click-based evaluation towards multi-click analysis, and presents a general, comprehensive method to evaluating navigability of arbitrary recommendation algorithms.

  3. The effect of navigational expertise on wayfinding in new environments.

    PubMed

    Woollett, Katherine; Maguire, Eleanor A

    2010-12-01

    Becoming proficient at navigation in urban environments is something that we all aspire to. Here we asked whether being an expert at wayfinding in one environment has any effect on learning new spatial layouts. Licensed London taxi drivers are among the most proficient urban navigators, training for many years to find their way around a complex and irregularly-laid out city. We first tested how well they could learn the layout of an unfamiliar town compared with a group of non-taxi drivers. Second, we investigated how effectively taxi drivers could integrate a new district into their existing spatial representation of London. We found that taxi drivers were significantly better than control participants at executing routes through the new town, and representing it at a map-like survey level. However, the benefits of navigational expertise were not universal. Compared with their performance in the new town, taxi drivers were significantly poorer at learning the layout of a new area that had to be integrated with their existing knowledge of London. We consider reasons for this picture of facilitation and limitation, in particular drawing parallels with how knowledge acquisition occurs in the context of expertise in general.

  4. Improved artificial bee colony algorithm based gravity matching navigation method.

    PubMed

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-07-18

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position.

  5. An adaptive deep-coupled GNSS/INS navigation system with hybrid pre-filter processing

    NASA Astrophysics Data System (ADS)

    Wu, Mouyan; Ding, Jicheng; Zhao, Lin; Kang, Yingyao; Luo, Zhibin

    2018-02-01

    The deep-coupling of a global navigation satellite system (GNSS) with an inertial navigation system (INS) can provide accurate and reliable navigation information. There are several kinds of deeply-coupled structures. These can be divided mainly into coherent and non-coherent pre-filter based structures, which have their own strong advantages and disadvantages, especially in accuracy and robustness. In this paper, the existing pre-filters of the deeply-coupled structures are analyzed and modified to improve them firstly. Then, an adaptive GNSS/INS deeply-coupled algorithm with hybrid pre-filters processing is proposed to combine the advantages of coherent and non-coherent structures. An adaptive hysteresis controller is designed to implement the hybrid pre-filters processing strategy. The simulation and vehicle test results show that the adaptive deeply-coupled algorithm with hybrid pre-filters processing can effectively improve navigation accuracy and robustness, especially in a GNSS-challenged environment.

  6. Improved Artificial Bee Colony Algorithm Based Gravity Matching Navigation Method

    PubMed Central

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-01-01

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position. PMID:25046019

  7. Notch sensitivity jeopardizes titanium locking plate fatigue strength.

    PubMed

    Tseng, Wo-Jan; Chao, Ching-Kong; Wang, Chun-Chin; Lin, Jinn

    2016-12-01

    Notch sensitivity may compromise titanium-alloy plate fatigue strength. However, no studies providing head-to-head comparisons of stainless-steel or titanium-alloy locking plates exist. Custom-designed identically structured locking plates were made from stainless steel (F138 and F1314) or titanium alloy. Three screw-hole designs were compared: threaded screw-holes with angle edges (type I); threaded screw-holes with chamfered edges (type II); and non-threaded screw-holes with chamfered edges (type III). The plates' bending stiffness, bending strength, and fatigue life, were investigated. The stress concentration at the screw threads was assessed using finite element analyses (FEA). The titanium plates had higher bending strength than the F1314 and F138 plates (2.95:1.56:1) in static loading tests. For all metals, the type-III plate fatigue life was highest, followed by type-II and type-I. The type-III titanium plates had longer fatigue lives than their F138 counterparts, but the type-I and type-II titanium plates had significantly shorter fatigue lives. All F1314 plate types had longer fatigue lives than the type-III titanium plates. The FEA showed minimal stress difference (0.4%) between types II and III, but the stress for types II and III was lower (11.9% and 12.4%) than that for type I. The screw threads did not cause stress concentration in the locking plates in FEA, but may have jeopardized the fatigue strength, especially in the notch-sensitive titanium plates. Improvement to the locking plate design is necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Gravity influences top-down signals in visual processing.

    PubMed

    Cheron, Guy; Leroy, Axelle; Palmero-Soler, Ernesto; De Saedeleer, Caty; Bengoetxea, Ana; Cebolla, Ana-Maria; Vidal, Manuel; Dan, Bernard; Berthoz, Alain; McIntyre, Joseph

    2014-01-01

    Visual perception is not only based on incoming visual signals but also on information about a multimodal reference frame that incorporates vestibulo-proprioceptive input and motor signals. In addition, top-down modulation of visual processing has previously been demonstrated during cognitive operations including selective attention and working memory tasks. In the absence of a stable gravitational reference, the updating of salient stimuli becomes crucial for successful visuo-spatial behavior by humans in weightlessness. Here we found that visually-evoked potentials triggered by the image of a tunnel just prior to an impending 3D movement in a virtual navigation task were altered in weightlessness aboard the International Space Station, while those evoked by a classical 2D-checkerboard were not. Specifically, the analysis of event-related spectral perturbations and inter-trial phase coherency of these EEG signals recorded in the frontal and occipital areas showed that phase-locking of theta-alpha oscillations was suppressed in weightlessness, but only for the 3D tunnel image. Moreover, analysis of the phase of the coherency demonstrated the existence on Earth of a directional flux in the EEG signals from the frontal to the occipital areas mediating a top-down modulation during the presentation of the image of the 3D tunnel. In weightlessness, this fronto-occipital, top-down control was transformed into a diverging flux from the central areas toward the frontal and occipital areas. These results demonstrate that gravity-related sensory inputs modulate primary visual areas depending on the affordances of the visual scene.

  9. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial.

    PubMed

    Costa, Matthew L; Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

    2014-08-05

    To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. 18 trauma centres in the United Kingdom. 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient's experience of pain and disability to give a score out of 100. disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was -1.3, 95% confidence interval -4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Contrary to the existing literature, and against the rapidly increasing use of locking plate fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Current Controlled Trials ISCRTN 31379280. UKCRN 8956. © Costa et al 2014.

  10. 29 CFR 1926.450 - Scope, application and definitions applicable to this subpart.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... one who is capable of identifying existing and predictable hazards in the surroundings or working... locking together the tubes of a tube and coupler scaffold. Crawling board (chicken ladder) means a... alternative designs, materials or methods to protect against a hazard which the employer can demonstrate will...

  11. 30 CFR 56.9300 - Berms or guardrails.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  12. 30 CFR 56.9300 - Berms or guardrails.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  13. 30 CFR 57.9300 - Berms or guardrails.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  14. 30 CFR 56.9300 - Berms or guardrails.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  15. 30 CFR 57.9300 - Berms or guardrails.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  16. 30 CFR 57.9300 - Berms or guardrails.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  17. 30 CFR 57.9300 - Berms or guardrails.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  18. 30 CFR 56.9300 - Berms or guardrails.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: (1) Locked gates are installed at the entrance points to the roadway. (2) Signs are posted warning... shall include the width, slope and alignment of the road, the type of equipment using the road, the road material, and any hazardous conditions which may exist. (5) Road surface traction is not impaired by...

  19. R AND D 100 EARLYBIRD AWARD ENTRY

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dugan, J; Debbie Chapman, D

    2007-01-30

    The Smart Latch{trademark} is an electronically enhanced door lockset device for industrial and consumer applications, which uses existing neural network technology to analyze the sequence, timing, and acoustic signatures associated with lockset functions and provides immediate indication of failure to correctly lock and latch. It essentially ''listens'' to and learns the sequences and acoustic signatures associated with lockset function and latching. When triggered by specific door activity the Smart Latch{trademark} begins analyzing sequences, frequencies and other parameters. With a satisfactory outcome the device provides positive feedback (e.g. visual and/or audible) and returns to a ''sleep'' state awaiting the next activity.more » If any part of the normal door operation, including latching and length of time, are incorrect various alarm signals can be generated. With electronics and 5+ year battery integrated, the device is simple to install and transparent to the user. Because the device uses proven voice recognition algorithms, it could meet or exceed the performance of the human ear in detecting the unique and complex acoustic signature associated with a properly operating and secured door. Unlike existing technologies, such as limit switches, it is not easily spoofed or defeated and has a high level of immunity to interference. The Smart Latch{trademark} technology can be integrated into existing lockset and door hardware designs, including both low price consumer products and high end electronic/cipher locks. The concept and design are based on a simple security industry adage: ''It isn't locked if it isn't latched''. Even the most elaborate and robust security barriers are of little use if the locking and latching mechanisms are not properly functioning and engaged. Smart Latch{trademark} provides automatic verification of the first and most important step in facility security: Close and properly latch doors and barriers. It is a compelling product for households with children, elderly, or high traffic areas such as an office where a properly closed and latched door is essential for security and safety. In an age of ever increasing security concerns and limited human resources, Smart Latch{trademark} can be a significant addition to the $20 billion plus industrial and consumer lockset market. The Smart Latch{trademark} is unique because: (1) as an inexpensive, battery powered, stand-alone device or as integrated into any standard consumer lock set, the device uses neural network technology to analyze the acoustic signatures associated with normal door operation and generates an alert if a door is not latched correctly and within a set amount of time. (2) It is not easily spoofed or defeated. (3) Installation, setup, and use are simple.« less

  20. Performance Improvement of Receivers Based on Ultra-Tight Integration in GNSS-Challenged Environments

    PubMed Central

    Qin, Feng; Zhan, Xingqun; Du, Gang

    2013-01-01

    Ultra-tight integration was first proposed by Abbott in 2003 with the purpose of integrating a global navigation satellite system (GNSS) and an inertial navigation system (INS). This technology can improve the tracking performances of a receiver by reconfiguring the tracking loops in GNSS-challenged environments. In this paper, the models of all error sources known to date in the phase lock loops (PLLs) of a standard receiver and an ultra-tightly integrated GNSS/INS receiver are built, respectively. Based on these models, the tracking performances of the two receivers are compared to verify the improvement due to the ultra-tight integration. Meanwhile, the PLL error distributions of the two receivers are also depicted to analyze the error changes of the tracking loops. These results show that the tracking error is significantly reduced in the ultra-tightly integrated GNSS/INS receiver since the receiver's dynamics are estimated and compensated by an INS. Moreover, the mathematical relationship between the tracking performances of the ultra-tightly integrated GNSS/INS receiver and the quality of the selected inertial measurement unit (IMU) is derived from the error models and proved by the error comparisons of four ultra-tightly integrated GNSS/INS receivers aided by different grade IMUs.

  1. Narrowing the College Opportunity Gap: Helping Students and Families Navigate the Financial Aid Process

    ERIC Educational Resources Information Center

    Owen, Laura

    2012-01-01

    The number of students enrolling in post-secondary institutions in the U.S. has slowly been rising over the last 10 years, yet gaps continue to exist in terms of who attends college and persists through graduation. Minority and low income students often lack the guidance needed to navigate the college enrollment process and as a result, remain…

  2. 33 CFR 148.215 - What if a port has plans for a deep draft channel and harbor?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... General § 148.215 What if a port has plans for a deep draft channel and harbor? (a) If a State port will be directly connected by pipeline to a proposed deepwater port, and has existing plans for a deep... deep draft channel and harbor? 148.215 Section 148.215 Navigation and Navigable Waters COAST GUARD...

  3. Broadcasting GPS integrity information using Loran-C

    NASA Astrophysics Data System (ADS)

    Lo, Sherman Chih

    The United States Federal Aviation Administration (FAA) will adopt the Global Positioning System (GPS) as its primary navigation systems for aviation as stated by the Federal Radionavigation Plans (FRP) of 1996 and 1999. The FRP also proposes the reduction or termination of some existing radionavigation system in favor of GPS and satellite navigation. It may be beneficial to retain some of these existing terrestrial navigation systems if they can provide increased safety and redundancy to the GPS based architecture. One manner in which this can be done is by using or creating a data link on these existing radionavigation systems. These systems thus can provide both navigation and an additional broadcast of GPS integrity information. This thesis examines the use of terrestrial data links to provide Wide Area Augmentation System (WAAS) based GPS integrity information for aviation. The thesis focuses on using Loran-C to broadcast WAAS data. Analysis and experimental results demonstrating the capabilities of these designs are also discussed. Using Loran for this purpose requires increasing its data capacity. Many Loran modulation schemes are developed and analyzed. The data rates developed significantly increased the Loran data capacity. However, retaining compatibility with Loran legacy users resulted in data rates below the WARS data rate of 250 bps. As a result, this thesis also examines means of reducing the data requirements for WAAS information. While higher data rates offer improved performance and compatibility with WAAS, this thesis demonstrates that higher rates incur greater interference. Therefore, this work develops and considers a 108 bps and 167 bps Loran GPS integrity channel (LOGIC) design. The performance of the two designs illustrates some of the advantages and disadvantages of using a higher data rate. Analysis demonstrated means of maintaining integrity with these low data rate systems and determined the theoretical capabilities of the systems. The system was tested empirically by developing software that generated the LOGIC message and applied these messages to a GPS user. The resulting 108 bps and 167 bps systems demonstrated capability to provide lateral navigation/vertical navigation (LNAV/VNAV) and approach with vertical guidance (APV) respectively.

  4. [Arthrodesis (with/without correction) of the ankle and subtalar joint: A3 nail fixation with triple bending and mechanical navigation].

    PubMed

    Richter, M

    2014-08-01

    Restoration of a stable and plantigrade foot in deformities of the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joints. Deformities at the ankle and/or hindfoot and concomitant degenerative changes at the ankle and subtalar joint. Failed (corrective) arthrodesis of the ankle and subtalar joints. Fused ankle and degeneration of the subtalar joint. Failed total ankle replacement with insufficient substance of talar body and/or degeneration of subtalar joint. Massive hindfoot instability. Active local infection or relevant vascular insufficiency, possible preservation of the ankle or subtalar joint (relative contraindication). Prone position and posterolateral approach to ankle and subtalar joints (alternative supine position/anterior approach; lateral position/lateral approach). Exposition of ankle and subtalar joints and removal of remaining cartilage. Optional corrective osteotomies and/or bone grafting. Correction and optional fixation of the corrected position with 2.0 mm K-wires. Mechanically navigated insertion of a retrograde guide wire in projection of the tibial axis and insertion of a second guide wire through the entry point of the nail lateral and dorsal to the tibial axis. Reaming and insertion of the A3 nail with a distal double bend; one posterior and one lateral, and a proximal bend corresponding to a slight recurvatum. Insertion of locking screws into the calcaneus, talus and tibia (twice with optional static or dynamic locking). Optional compression between calcaneus and talus, and between tibia and talus. Insertion of a drainage and layer-wise closure. For the first 6 weeks 15 kg partial weight bearing in an orthosis, followed by full weight bearing in a stable standard shoe. In October 2010 (n = 2) and from 15 October 2011 to 13 April 2012 (n = 26) 28 arthrodeses (with/without correction) with A3 fixation were performed. In all cases, exact nail placement was achieved. Thirteen cases completed follow-up (3-11 months) and showed timely fusion and full mobilization.

  5. A Strapdown Interial Navigation System/Beidou/Doppler Velocity Log Integrated Navigation Algorithm Based on a Cubature Kalman Filter

    PubMed Central

    Gao, Wei; Zhang, Ya; Wang, Jianguo

    2014-01-01

    The integrated navigation system with strapdown inertial navigation system (SINS), Beidou (BD) receiver and Doppler velocity log (DVL) can be used in marine applications owing to the fact that the redundant and complementary information from different sensors can markedly improve the system accuracy. However, the existence of multisensor asynchrony will introduce errors into the system. In order to deal with the problem, conventionally the sampling interval is subdivided, which increases the computational complexity. In this paper, an innovative integrated navigation algorithm based on a Cubature Kalman filter (CKF) is proposed correspondingly. A nonlinear system model and observation model for the SINS/BD/DVL integrated system are established to more accurately describe the system. By taking multi-sensor asynchronization into account, a new sampling principle is proposed to make the best use of each sensor's information. Further, CKF is introduced in this new algorithm to enable the improvement of the filtering accuracy. The performance of this new algorithm has been examined through numerical simulations. The results have shown that the positional error can be effectively reduced with the new integrated navigation algorithm. Compared with the traditional algorithm based on EKF, the accuracy of the SINS/BD/DVL integrated navigation system is improved, making the proposed nonlinear integrated navigation algorithm feasible and efficient. PMID:24434842

  6. Patient navigation across the spectrum of women's health care in the United States.

    PubMed

    McKenney, Kathryn M; Martinez, Noelle G; Yee, Lynn M

    2018-03-01

    Patient navigation is a patient-centered intervention that uses trained personnel to identify patient-level barriers, including financial, cultural, logistical, and educational obstacles to health care and then mitigate these barriers to facilitate complete and timely access to health services. For example, to assist a woman with Medicaid who is seeking postpartum care, a patient navigator could help her schedule an appointment before her insurance benefits change, coordinate transportation and child care, give her informational pamphlets on contraception options, and accompany her to the appointment to ensure her questions are answered. Existing studies examining the efficacy of patient navigation interventions show particularly striking benefits in the realm of cancer care, including gynecological oncology; patient navigation has been demonstrated to increase access to screening, shorten time to diagnostic resolution, and improve cancer outcomes, particularly in health disparity populations, such as women of color, rural populations, and poor women. Because of the successes in cancer care at reducing disparities in health care access and health outcomes, patient navigation has the potential to improve care and reduce disparities in obstetric and benign gynecological care. We review the concept of patient navigation, offer potential roles for patient navigation in obstetrics and gynecology, and discuss areas for further investigation. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Bioinspired magnetoreception and navigation using magnetic signatures as waypoints.

    PubMed

    Taylor, Brian K

    2018-05-15

    Diverse taxa use Earth's magnetic field in conjunction with other sensory modalities to accomplish navigation tasks ranging from local homing to long-distance migration across continents and ocean basins. However, despite extensive research, the mechanisms that underlie animal magnetoreception are not clearly understood, and how animals use Earth's magnetic field to navigate is an active area of investigation. Concurrently, Earth's magnetic field offers a signal that engineered systems can leverage for navigation in environments where man-made systems such as GPS are unavailable or unreliable. Using a proxy for Earth's magnetic field, and inspired by migratory animal behavior, this work implements a behavioral strategy that uses combinations of magnetic field properties as rare or unique signatures that mark specific locations. Using a discrete number of these signatures as goal waypoints, the strategy navigates through a closed set of points several times in a variety of environmental conditions, and with various levels of sensor noise. The results from this engineering/quantitative biology approach support existing notions that some animals may use combinations of magnetic properties as navigational markers, and provides insights into features and constraints that would enable navigational success or failure. The findings also offer insights into how autonomous engineered platforms might be designed to leverage the magnetic field as a navigational resource.

  8. A Novel Grid SINS/DVL Integrated Navigation Algorithm for Marine Application

    PubMed Central

    Kang, Yingyao; Zhao, Lin; Cheng, Jianhua; Fan, Xiaoliang

    2018-01-01

    Integrated navigation algorithms under the grid frame have been proposed based on the Kalman filter (KF) to solve the problem of navigation in some special regions. However, in the existing study of grid strapdown inertial navigation system (SINS)/Doppler velocity log (DVL) integrated navigation algorithms, the Earth models of the filter dynamic model and the SINS mechanization are not unified. Besides, traditional integrated systems with the KF based correction scheme are susceptible to measurement errors, which would decrease the accuracy and robustness of the system. In this paper, an adaptive robust Kalman filter (ARKF) based hybrid-correction grid SINS/DVL integrated navigation algorithm is designed with the unified reference ellipsoid Earth model to improve the navigation accuracy in middle-high latitude regions for marine application. Firstly, to unify the Earth models, the mechanization of grid SINS is introduced and the error equations are derived based on the same reference ellipsoid Earth model. Then, a more accurate grid SINS/DVL filter model is designed according to the new error equations. Finally, a hybrid-correction scheme based on the ARKF is proposed to resist the effect of measurement errors. Simulation and experiment results show that, compared with the traditional algorithms, the proposed navigation algorithm can effectively improve the navigation performance in middle-high latitude regions by the unified Earth models and the ARKF based hybrid-correction scheme. PMID:29373549

  9. Numerical evaluation of mobile robot navigation in static indoor environment via EGAOR Iteration

    NASA Astrophysics Data System (ADS)

    Dahalan, A. A.; Saudi, A.; Sulaiman, J.; Din, W. R. W.

    2017-09-01

    One of the key issues in mobile robot navigation is the ability for the robot to move from an arbitrary start location to a specified goal location without colliding with any obstacles while traveling, also known as mobile robot path planning problem. In this paper, however, we examined the performance of a robust searching algorithm that relies on the use of harmonic potentials of the environment to generate smooth and safe path for mobile robot navigation in a static known indoor environment. The harmonic potentials will be discretized by using Laplacian’s operator to form a system of algebraic approximation equations. This algebraic linear system will be computed via 4-Point Explicit Group Accelerated Over-Relaxation (4-EGAOR) iterative method for rapid computation. The performance of the proposed algorithm will then be compared and analyzed against the existing algorithms in terms of number of iterations and execution time. The result shows that the proposed algorithm performed better than the existing methods.

  10. Crossed and Locked Quotes in a Multi-Market Simulation

    PubMed Central

    Todd, Andrew; Beling, Peter; Scherer, William

    2016-01-01

    Financial markets are often fragmented, introducing the possibility that quotes in identical securities may become crossed or locked. There are a number of theoretical explanations for the existence of crossed and locked quotes, including competition, simultaneous actions, inattentiveness, fee structure and market access. In this paper, we perform a simulation experiment designed to examine the effect of simple order routing procedures on the properties of a fragmented market consisting of a single security trading in two independent limit order books. The quotes in the two markets are connected solely by the routing decision of the market participants. We report on the health of the consolidated market as measured by the duration of crossed and locked states, as well as the spread and the volatility of transaction prices in the consolidated market. We aim to quantify exactly how the prevalence of order routing among a population of market participants affects properties of the consolidated market. Our model contributes to the zero-intelligence literature by treating order routing as an experimental variable. Additionally, we introduce a parsimonious heuristic for limit order routing, allowing us to study the effects of both market order routing and limit order routing. Our model refines intuition for the sometimes subtle relationships between the prevalence of order routing and various market measures. Our model also provides a benchmark for more complex agent-based models. PMID:26959416

  11. Crossed and Locked Quotes in a Multi-Market Simulation.

    PubMed

    Todd, Andrew; Beling, Peter; Scherer, William

    2016-01-01

    Financial markets are often fragmented, introducing the possibility that quotes in identical securities may become crossed or locked. There are a number of theoretical explanations for the existence of crossed and locked quotes, including competition, simultaneous actions, inattentiveness, fee structure and market access. In this paper, we perform a simulation experiment designed to examine the effect of simple order routing procedures on the properties of a fragmented market consisting of a single security trading in two independent limit order books. The quotes in the two markets are connected solely by the routing decision of the market participants. We report on the health of the consolidated market as measured by the duration of crossed and locked states, as well as the spread and the volatility of transaction prices in the consolidated market. We aim to quantify exactly how the prevalence of order routing among a population of market participants affects properties of the consolidated market. Our model contributes to the zero-intelligence literature by treating order routing as an experimental variable. Additionally, we introduce a parsimonious heuristic for limit order routing, allowing us to study the effects of both market order routing and limit order routing. Our model refines intuition for the sometimes subtle relationships between the prevalence of order routing and various market measures. Our model also provides a benchmark for more complex agent-based models.

  12. Allosteric mechanism controls traffic in the chaperone/usher pathway.

    PubMed

    Di Yu, Xiao; Dubnovitsky, Anatoly; Pudney, Alex F; Macintyre, Sheila; Knight, Stefan D; Zavialov, Anton V

    2012-11-07

    Many virulence organelles of Gram-negative bacterial pathogens are assembled via the chaperone/usher pathway. The chaperone transports organelle subunits across the periplasm to the outer membrane usher, where they are released and incorporated into growing fibers. Here, we elucidate the mechanism of the usher-targeting step in assembly of the Yersinia pestis F1 capsule at the atomic level. The usher interacts almost exclusively with the chaperone in the chaperone:subunit complex. In free chaperone, a pair of conserved proline residues at the beginning of the subunit-binding loop form a "proline lock" that occludes the usher-binding surface and blocks usher binding. Binding of the subunit to the chaperone rotates the proline lock away from the usher-binding surface, allowing the chaperone-subunit complex to bind to the usher. We show that the proline lock exists in other chaperone/usher systems and represents a general allosteric mechanism for selective targeting of chaperone:subunit complexes to the usher and for release and recycling of the free chaperone. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Locked-mode avoidance and recovery without momentum input

    NASA Astrophysics Data System (ADS)

    Delgado-Aparicio, L.; Rice, J. E.; Wolfe, S.; Cziegler, I.; Gao, C.; Granetz, R.; Wukitch, S.; Terry, J.; Greenwald, M.; Sugiyama, L.; Hubbard, A.; Hugges, J.; Marmar, E.; Phillips, P.; Rowan, W.

    2015-11-01

    Error-field-induced locked-modes (LMs) have been studied in Alcator C-Mod at ITER-Bϕ, without NBI fueling and momentum input. Delay of the mode-onset and locked-mode recovery has been successfully obtained without external momentum input using Ion Cyclotron Resonance Heating (ICRH). The use of external heating in-sync with the error-field ramp-up resulted in a successful delay of the mode-onset when PICRH > 1 MW, which demonstrates the existence of a power threshold to ``unlock'' the mode; in the presence of an error field the L-mode discharge can transition into H-mode only when PICRH > 2 MW and at high densities, avoiding also the density pump-out. The effects of ion heating observed on unlocking the core plasma may be due to ICRH induced flows in the plasma boundary, or modifications of plasma profiles that changed the underlying turbulence. This work was performed under US DoE contracts including DE-FC02-99ER54512 and others at MIT, DE-FG03-96ER-54373 at University of Texas at Austin, and DE-AC02-09CH11466 at PPPL.

  14. Geomagnetic Navigation of Autonomous Underwater Vehicle Based on Multi-objective Evolutionary Algorithm.

    PubMed

    Li, Hong; Liu, Mingyong; Zhang, Feihu

    2017-01-01

    This paper presents a multi-objective evolutionary algorithm of bio-inspired geomagnetic navigation for Autonomous Underwater Vehicle (AUV). Inspired by the biological navigation behavior, the solution was proposed without using a priori information, simply by magnetotaxis searching. However, the existence of the geomagnetic anomalies has significant influence on the geomagnetic navigation system, which often disrupts the distribution of the geomagnetic field. An extreme value region may easily appear in abnormal regions, which makes AUV lost in the navigation phase. This paper proposes an improved bio-inspired algorithm with behavior constraints, for sake of making AUV escape from the abnormal region. First, the navigation problem is considered as the optimization problem. Second, the environmental monitoring operator is introduced, to determine whether the algorithm falls into the geomagnetic anomaly region. Then, the behavior constraint operator is employed to get out of the abnormal region. Finally, the termination condition is triggered. Compared to the state-of- the-art, the proposed approach effectively overcomes the disturbance of the geomagnetic abnormal. The simulation result demonstrates the reliability and feasibility of the proposed approach in complex environments.

  15. Design, development and evaluation of a compact telerobotic catheter navigation system.

    PubMed

    Tavallaei, Mohammad Ali; Gelman, Daniel; Lavdas, Michael Konstantine; Skanes, Allan C; Jones, Douglas L; Bax, Jeffrey S; Drangova, Maria

    2016-09-01

    Remote catheter navigation systems protect interventionalists from scattered ionizing radiation. However, these systems typically require specialized catheters and extensive operator training. A new compact and sterilizable telerobotic system is described, which allows remote navigation of conventional tip-steerable catheters, with three degrees of freedom, using an interface that takes advantage of the interventionalist's existing dexterity skills. The performance of the system is evaluated ex vivo and in vivo for remote catheter navigation and ablation delivery. The system has absolute errors of 0.1 ± 0.1 mm and 7 ± 6° over 100 mm of axial motion and 360° of catheter rotation, respectively. In vivo experiments proved the safety of the proposed telerobotic system and demonstrated the feasibility of remote navigation and delivery of ablation. The proposed telerobotic system allows the interventionalist to use conventional steerable catheters; while maintaining a safe distance from the radiation source, he/she can remotely navigate the catheter and deliver ablation lesions. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Geomagnetic Navigation of Autonomous Underwater Vehicle Based on Multi-objective Evolutionary Algorithm

    PubMed Central

    Li, Hong; Liu, Mingyong; Zhang, Feihu

    2017-01-01

    This paper presents a multi-objective evolutionary algorithm of bio-inspired geomagnetic navigation for Autonomous Underwater Vehicle (AUV). Inspired by the biological navigation behavior, the solution was proposed without using a priori information, simply by magnetotaxis searching. However, the existence of the geomagnetic anomalies has significant influence on the geomagnetic navigation system, which often disrupts the distribution of the geomagnetic field. An extreme value region may easily appear in abnormal regions, which makes AUV lost in the navigation phase. This paper proposes an improved bio-inspired algorithm with behavior constraints, for sake of making AUV escape from the abnormal region. First, the navigation problem is considered as the optimization problem. Second, the environmental monitoring operator is introduced, to determine whether the algorithm falls into the geomagnetic anomaly region. Then, the behavior constraint operator is employed to get out of the abnormal region. Finally, the termination condition is triggered. Compared to the state-of- the-art, the proposed approach effectively overcomes the disturbance of the geomagnetic abnormal. The simulation result demonstrates the reliability and feasibility of the proposed approach in complex environments. PMID:28747884

  17. The use of x-ray pulsar-based navigation method for interplanetary flight

    NASA Astrophysics Data System (ADS)

    Yang, Bo; Guo, Xingcan; Yang, Yong

    2009-07-01

    As interplanetary missions are increasingly complex, the existing unique mature interplanetary navigation method mainly based on radiometric tracking techniques of Deep Space Network can not meet the rising demands of autonomous real-time navigation. This paper studied the applications for interplanetary flights of a new navigation technology under rapid development-the X-ray pulsar-based navigation for spacecraft (XPNAV), and valued its performance with a computer simulation. The XPNAV is an excellent autonomous real-time navigation method, and can provide comprehensive navigation information, including position, velocity, attitude, attitude rate and time. In the paper the fundamental principles and time transformation of the XPNAV were analyzed, and then the Delta-correction XPNAV blending the vehicles' trajectory dynamics with the pulse time-of-arrival differences at nominal and estimated spacecraft locations within an Unscented Kalman Filter (UKF) was discussed with a background mission of Mars Pathfinder during the heliocentric transferring orbit. The XPNAV has an intractable problem of integer pulse phase cycle ambiguities similar to the GPS carrier phase navigation. This article innovatively proposed the non-ambiguity assumption approach based on an analysis of the search space array method to resolve pulse phase cycle ambiguities between the nominal position and estimated position of the spacecraft. The simulation results show that the search space array method are computationally intensive and require long processing time when the position errors are large, and the non-ambiguity assumption method can solve ambiguity problem quickly and reliably. It is deemed that autonomous real-time integrated navigation system of the XPNAV blending with DSN, celestial navigation, inertial navigation and so on will be the development direction of interplanetary flight navigation system in the future.

  18. Mission Analysis, Operations, and Navigation Toolkit Environment (Monte) Version 040

    NASA Technical Reports Server (NTRS)

    Sunseri, Richard F.; Wu, Hsi-Cheng; Evans, Scott E.; Evans, James R.; Drain, Theodore R.; Guevara, Michelle M.

    2012-01-01

    Monte is a software set designed for use in mission design and spacecraft navigation operations. The system can process measurement data, design optimal trajectories and maneuvers, and do orbit determination, all in one application. For the first time, a single software set can be used for mission design and navigation operations. This eliminates problems due to different models and fidelities used in legacy mission design and navigation software. The unique features of Monte 040 include a blowdown thruster model for GRAIL (Gravity Recovery and Interior Laboratory) with associated pressure models, as well as an updated, optimalsearch capability (COSMIC) that facilitated mission design for ARTEMIS. Existing legacy software lacked the capabilities necessary for these two missions. There is also a mean orbital element propagator and an osculating to mean element converter that allows long-term orbital stability analysis for the first time in compiled code. The optimized trajectory search tool COSMIC allows users to place constraints and controls on their searches without any restrictions. Constraints may be user-defined and depend on trajectory information either forward or backwards in time. In addition, a long-term orbit stability analysis tool (morbiter) existed previously as a set of scripts on top of Monte. Monte is becoming the primary tool for navigation operations, a core competency at JPL. The mission design capabilities in Monte are becoming mature enough for use in project proposals as well as post-phase A mission design. Monte has three distinct advantages over existing software. First, it is being developed in a modern paradigm: object- oriented C++ and Python. Second, the software has been developed as a toolkit, which allows users to customize their own applications and allows the development team to implement requirements quickly, efficiently, and with minimal bugs. Finally, the software is managed in accordance with the CMMI (Capability Maturity Model Integration), where it has been ap praised at maturity level 3.

  19. Employer-provided health insurance and the incidence of job lock: a literature review and empirical test.

    PubMed

    Rashad, Inas; Sarpong, Eric

    2008-12-01

    The incidence of 'job lock' in the health insurance context has long been viewed as a potential problem with employer-provided health insurance, a concept that was instrumental in the passage of the United States Consolidated Omnibus Budget Reconciliation Act of 1986, and later, the Health Insurance Portability and Accountability Act in 1996. Several recent developments in healthcare in the USA include declining healthcare coverage and a noticeable shift in the burden of medical care costs to employees. If these developments cause employees with employer-provided health insurance to feel locked into their jobs, optimal job matches in the labor force may not take place. A summary of the seminal papers in the current literature on the topic of job lock is given, followed by an empirical exercise using single individuals from the National Health Interview Survey (1997-2003) and the 1979 cohort of the National Longitudinal Survey of Youth (1989-2000). Econometric methods used include difference in differences, ordinary least squares and individual fixed effects models, in gauging the potential effect that employer-provided health insurance may have on job tenure and voluntary job departure. Our findings are consistent with recent assertions that there is some evidence of job lock. Individuals with employer-provided health insurance stay on the job 16% longer and are 60% less likely to voluntarily leave their jobs than those with insurance that is not provided by their employers. Productivity may not be optimal if incentives are altered owing to the existence of fringe benefits, such as health insurance. Further research in this area should determine whether legislation beyond the Consolidated Omnibus Budget Reconciliation Act and Health Insurance Portability and Accountability Act laws is needed.

  20. Error field detection in DIII-D by magnetic steering of locked modes

    DOE PAGES

    Shiraki, Daisuke; La Haye, Robert J.; Logan, Nikolas C.; ...

    2014-02-20

    Optimal correction coil currents for the n = 1 intrinsic error field of the DIII-D tokamak are inferred by applying a rotating external magnetic perturbation to steer the phase of a saturated locked mode with poloidal/toroidal mode number m/n = 2/1. The error field is detected non-disruptively in a single discharge, based on the toroidal torque balance of the resonant surface, which is assumed to be dominated by the balance of resonant electromagnetic torques. This is equivalent to the island being locked at all times to the resonant 2/1 component of the total of the applied and intrinsic error fields,more » such that the deviation of the locked mode phase from the applied field phase depends on the existing error field. The optimal set of correction coil currents is determined to be those currents which best cancels the torque from the error field, based on fitting of the torque balance model. The toroidal electromagnetic torques are calculated from experimental data using a simplified approach incorporating realistic DIII-D geometry, and including the effect of the plasma response on island torque balance based on the ideal plasma response to external fields. This method of error field detection is demonstrated in DIII-D discharges, and the results are compared with those based on the onset of low-density locked modes in ohmic plasmas. Furthermore, this magnetic steering technique presents an efficient approach to error field detection and is a promising method for ITER, particularly during initial operation when the lack of auxiliary heating systems makes established techniques based on rotation or plasma amplification unsuitable.« less

  1. Applications of 1.55 μm optically injection-locked VCSELs in wavelength division multiplexed passive optical networks

    NASA Astrophysics Data System (ADS)

    Wong, Elaine; Zhao, Xiaoxue; Chang-Hasnain, Connie J.; Hofmann, Werner; Amann, Marcus C.

    2007-11-01

    In this paper, we will discuss the utilization of optically injection-locked (OIL) 1.55 μm vertical-cavity surface-emitting lasers (VCSELs) for operation as low-cost, stable, directly modulated, and potentially uncooled transmitters, whereby the injection-locking master source is furnished by modulated downstream signals. Such a transmitter will find useful application in wavelength division multiplexed passive optical networks (WDM-PONs) which is actively being developed to meet the ever-increasing bandwidth demands of end users. Our scheme eliminates the need for external injection locking optical sources, external modulators, and wavelength stabilization circuitry. We show through experiments that the injection-locked VCSEL favors low injection powers and responds only strongly to the carrier but not the modulated data of the downstream signal. Further, we will discuss results from experimental studies performed on the dependence of OIL-VCSELs in bidirectional networks on the degree of Rayleigh backscattered signal and extinction ratio. We show that error-free upstream performance can be achieved when the upstream signal to Rayleigh backscattering ratio is greater than 13.4 dB, and with minimal dependence on the downstream extinction ratio. We will also review a fault monitoring and localization scheme based on a highly-sensitive yet low-cost monitor comprising a low output power broadband source and low bandwidth detectors. The proposed scheme benefits from the high reflectivity top distributed Bragg reflector mirror of the OIL-VCSEL, incurring only a minimal penalty on the upstream transmissions of the existing infrastructure. Such a scheme provides fault monitoring without having to further invest in the upgrade of customer premises.

  2. OM300 Direction Drilling Module

    DOE Data Explorer

    MacGugan, Doug

    2013-08-22

    OM300 – Geothermal Direction Drilling Navigation Tool: Design and produce a prototype directional drilling navigation tool capable of high temperature operation in geothermal drilling Accuracies of 0.1° Inclination and Tool Face, 0.5° Azimuth Environmental Ruggedness typical of existing oil/gas drilling Multiple Selectable Sensor Ranges High accuracy for navigation, low bandwidth High G-range & bandwidth for Stick-Slip and Chirp detection Selectable serial data communications Reduce cost of drilling in high temperature Geothermal reservoirs Innovative aspects of project Honeywell MEMS* Vibrating Beam Accelerometers (VBA) APS Flux-gate Magnetometers Honeywell Silicon-On-Insulator (SOI) High-temperature electronics Rugged High-temperature capable package and assembly process

  3. Quick-Change Ceramic Flame Holder for High-Output Torches

    NASA Technical Reports Server (NTRS)

    Haskin, Henry

    2010-01-01

    Researchers at NASA's Langley Research Center have developed a new ceramic design flame holder with a service temperature of 4,000 F (2,204 C). The combination of high strength and high temperature capability, as well as a twist-lock mounting method to the steel burner, sets this flame holder apart from existing technology.

  4. Equity and Access in Charter Schools: Identifying Issues and Solutions

    ERIC Educational Resources Information Center

    Marshall, David T.

    2017-01-01

    School choice exists in American public schooling, even where official school choice policy is absent. Parents with means can elect to live in neighborhoods zoned for desirable schools, whereas parents without means are locked out of that opportunity. In their ideal, charter schools have the ability to expand access to desirable schools to…

  5. Systemic Success in Physical Education: The East Valley Phenomenon

    ERIC Educational Resources Information Center

    Prusak, Keven A.; Pennington, Todd; Graser, Susan Vincent; Beighle, Aaron; Morgan, Charles F.

    2010-01-01

    Siedentop and Locke (1997) proposed three critical elements that must exist in our profession to make a difference and achieve systemic success in physical education (SSPE): (a) quality PE in the schools, (b) effective physical education teacher education (PETE)programs, and (c) a working relationship between the two. Using Cuban's (1992)…

  6. Dependence of locked mode behavior on frequency and polarity of a rotating external magnetic perturbation

    NASA Astrophysics Data System (ADS)

    Inoue, S.; Shiraishi, J.; Takechi, M.; Matsunaga, G.; Isayama, A.; Hayashi, N.; Ide, S.

    2018-02-01

    Active control and stabilization of locked modes (LM) via rotating external magnetic perturbations are numerically investigated under a realistic low resistivity condition. To explore plasma responses to rotating and/or static external magnetic perturbations, we have developed a resistive magnetohydrodynamic code ‘AEOLUS-IT’. By using AEOLUS-IT, dependencies of mode behavior on frequency and polarity of the rotating magnetic perturbation are successfully clarified. Here, the rotational direction of the rotating magnetic perturbation to the equilibrium plasma rotation in the laboratory frame is referred to as ‘polarity’. The rotating magnetic perturbation acts on the background rotating plasma in the presence of a static field. Under such circumstances, there exist bifurcated states of the background rotating plasma, which should be taken into account when studying the dependence of the mode behavior on the rotating magnetic perturbation. It is found that there exist an optimum frequency and polarity of the rotating magnetic perturbation to control the LM, and that the LM is effectively stabilized by a co-polarity magnetic perturbation in comparison with a counter-polarity one.

  7. Water Quality And Sediment Evaluation for Inner Harbor Navigation Canal Lock Replacement Project, New Orleans, Louisiana

    DTIC Science & Technology

    2011-08-01

    1.6 - 16.0 (4.3) Trivalent Chromium 14.0 - 29.2 (22.1) 21.8 - 38.5 (26.5) 23.8 - 34.2 (30.7) 14.0 - 49.5 (26.7) 11.5 - 35.5 (23.0) Zinc 56.6 - 192...2.2) 0.80 - 1.9 1.4 Trivalent Chromium 12.5 - 16.9 (14.4) 11.2 - 19.5 (14.5) 22.2 -32.9 (26.4) 15.8 - 23.5 19.1 Zinc 53.8 - 100 (70.1) 41.3 - 107...3.6 (2.5) 0.30 - 0.53 Trivalent Chromium 6.9 - 9.2 (8.0) 11.9 - 16.5 (14.2) 15.0 - 34.1 (23.9) 4.2 - 7.1 Zinc 24.3 - 37.7 (32.0) 46.3 - 75.6 (61.0

  8. Research of autonomous celestial navigation based on new measurement model of stellar refraction

    NASA Astrophysics Data System (ADS)

    Yu, Cong; Tian, Hong; Zhang, Hui; Xu, Bo

    2014-09-01

    Autonomous celestial navigation based on stellar refraction has attracted widespread attention for its high accuracy and full autonomy．In this navigation method, establishment of accurate stellar refraction measurement model is the fundament and key issue to achieve high accuracy navigation. However, the existing measurement models are limited due to the uncertainty of atmospheric parameters. Temperature, pressure and other factors which affect the stellar refraction within the height of earth's stratosphere are researched, and the varying model of atmosphere with altitude is derived on the basis of standard atmospheric data. Furthermore, a novel measurement model of stellar refraction in a continuous range of altitudes from 20 km to 50 km is produced by modifying the fixed altitude (25 km) measurement model, and equation of state with the orbit perturbations is established, then a simulation is performed using the improved Extended Kalman Filter. The results show that the new model improves the navigation accuracy, which has a certain practical application value.

  9. Optical Phase Recovery and Locking in a PPM Laser Communication Link

    NASA Technical Reports Server (NTRS)

    Aveline, David C.; Yu, Nan; Farr, William H.

    2012-01-01

    Free-space optical communication holds great promise for future space missions requiring high data rates. For data communication in deep space, the current architecture employs pulse position modulation (PPM). In this scheme, the light is transmitted and detected as pulses within an array of time slots. While the PPM method is efficient for data transmission, the phase of the laser light is not utilized. The phase coherence of a PPM optical signal has been investigated with the goal of developing a new laser communication and ranging scheme that utilizes optical coherence within the established PPM architecture and photon-counting detection (PCD). Experimental measurements of a PPM modulated optical signal were conducted, and modeling code was developed to generate random PPM signals and simulate spectra via FFT (Fast Fourier Transform) analysis. The experimental results show very good agreement with the simulations and confirm that coherence is preserved despite modulation with high extinction ratios and very low duty cycles. A real-time technique has been developed to recover the phase information through the mixing of a PPM signal with a frequency-shifted local oscillator (LO). This mixed signal is amplified, filtered, and integrated to generate a voltage proportional to the phase of the modulated signal. By choosing an appropriate time constant for integration, one can maintain a phase lock despite long dark times between consecutive pulses with low duty cycle. A proof-of-principle demonstration was first achieved with an RF-based PPM signal and test setup. With the same principle method, an optical carrier within a PPM modulated laser beam could also be tracked and recovered. A reference laser was phase-locked to an independent pulsed laser signal with low-duty-cycle pseudo-random PPM codes. In this way, the drifting carrier frequency in the primary laser source is tracked via its phase change in the mixed beat note, while the corresponding voltage feedback maintains the phase lock between the two laser sources. The novelty and key significance of this work is that the carrier phase information can be harnessed within an optical communication link based on PPM-PCD architecture. This technology development could lead to quantum-limited efficient performance within the communication link itself, as well as enable high-resolution optical tracking capabilities for planetary science and spacecraft navigation.

  10. GPS-Based Navigation and Orbit Determination for the AMSAT Phase 3D Satellite

    NASA Technical Reports Server (NTRS)

    Davis, George; Carpenter, Russell; Moreau, Michael; Bauer, Frank H.; Long, Anne; Kelbel, David; Martin, Thomas

    2002-01-01

    This paper summarizes the results of processing GPS data from the AMSAT Phase 3D (AP3) satellite for real-time navigation and post-processed orbit determination experiments. AP3 was launched into a geostationary transfer orbit (GTO) on November 16, 2000 from Kourou, French Guiana, and then was maneuvered into its HEO over the next several months. It carries two Trimble TANS Vector GPS receivers for signal reception at apogee and at perigee. Its spin stabilization mode currently makes it favorable to track GPS satellites from the backside of the constellation while at perigee, and to track GPS satellites from below while at perigee. To date, the experiment has demonstrated that it is feasible to use GPS for navigation and orbit determination in HEO, which will be of great benefit to planned and proposed missions that will utilize such orbits for science observations. It has also shown that there are many important operational considerations to take into account. For example, GPS signals can be tracked above the constellation at altitudes as high as 58000 km, but sufficient amplification of those weak signals is needed. Moreover, GPS receivers can track up to 4 GPS satellites at perigee while moving as fast as 9.8 km/sec, but unless the receiver can maintain lock on the signals long enough, point solutions will be difficult to generate. The spin stabilization of AP3, for example, appears to cause signal levels to fluctuate as other antennas on the satellite block the signals. As a result, its TANS Vectors have been unable to lock on to the GPS signals long enough to down load the broadcast ephemeris and then generate position and velocity solutions. AP3 is currently in its eclipse season, and thus most of the spacecraft subsystems have been powered off. In Spring 2002, they will again be powered up and AP3 will be placed into a three-axis stabilization mode. This will significantly enhance the likelihood that point solutions can be generated, and perhaps more important, that the receiver clock can be synchronized to GPS time. This is extremely important for real-time and post-processed orbit determination, where removal of receiver clock bias from the data time tags is needed, for time-tagging of science observations. Current analysis suggests that the inability to generate point solutions has allowed the TANS Vector clock bias to drift freely, being perhaps as large as 5-7 seconds by October, 2001, thus causing up to 50 km of along-track orbit error. The data collected in May, 2002 while in three-axis stabilized mode should provide a significant improvement in the orbit determination results.

  11. Educator or Counselor? Navigating Uncertain Boundaries in the Clinical Environment.

    PubMed

    Lane, Annette M; Corcoran, Lynn

    2016-04-01

    Nurse educators in the clinical environment experience great rewards and challenges in their work with undergraduate students. However, closely working with students can lead to the challenge of intervening with those who are emotionally distressed. How do nurse educators navigate the precarious and subtle territory between educating and counseling? This article briefly reviews how boundaries are explored in nursing. Two case studies are presented to demonstrate how nurse educators can determine when their support and education begins to move into the counseling role. Finally, future directions for nurse educators are suggested. Little research exists that examines how nurse educators navigate the boundaries between educator and counselor roles with students in clinical settings. Navigating between the educator and counselor roles with students experiencing emotional distress in clinical settings can be challenging for nurse educators. Copyright 2016, SLACK Incorporated.

  12. U.S. Space Shuttle GPS navigation capability for all mission phases

    NASA Technical Reports Server (NTRS)

    Kachmar, Peter; Chu, William; Montez, Moises

    1993-01-01

    Incorporating a GPS capability on the Space Shuttle presented unique system integration design considerations and has led to an integration concept that has minimum impact on the existing Shuttle hardware and software systems. This paper presents the Space Shuttle GPS integrated design and the concepts used in implementing this GPS capability. The major focus of the paper is on the modifications that will be made to the navigation systems in the Space Shuttle General Purpose Computers (GPC) and on the Operational Requirements of the integrated GPS/GPC system. Shuttle navigation system architecture, functions and operations are discussed for the current system and with the GPS integrated navigation capability. The GPS system integration design presented in this paper has been formally submitted to the Shuttle Avionics Software Control Board for implementation in the on-board GPC software.

  13. Multiple beacons for supporting lunar landing navigation

    NASA Astrophysics Data System (ADS)

    Theil, Stephan; Bora, Leonardo

    2018-02-01

    The exploration and potential future exploitation of solar system bodies requires technologies for precise and safe landings. Current navigation systems for landing probes are relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. With a future transition from single exploration missions to more frequent first exploration and then exploitation missions, the implementation and operation of these missions changes, since it can be expected that a ground infrastructure on the target body is available in the vicinity of the landing site. In a previous paper, the impact of a single ground-based beacon on the navigation performance was investigated depending on the type of radiometric measurements and on the location of the beacon with respect to the landing site. This paper extends this investigation on options for ground-based multiple beacons supporting the on-board navigation system. It analyzes the impact on the achievable navigation accuracy. For that purpose, the paper introduces briefly the existing navigation architecture based on optical navigation and its extension with radiometric measurements. The same scenario of lunar landing as in the previous paper is simulated. The results are analyzed and discussed. They show a single beacon at a large distance along the landing trajectory and multiple beacons close to the landing site can improve the navigation performance. The results show how large the landing area can be increased where a sufficient navigation performance is achieved using the beacons.

  14. Situationally driven local navigation for mobile robots. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Slack, Marc Glenn

    1990-01-01

    For mobile robots to autonomously accommodate dynamically changing navigation tasks in a goal-directed fashion, they must employ navigation plans. Any such plan must provide for the robot's immediate and continuous need for guidance while remaining highly flexible in order to avoid costly computation each time the robot's perception of the world changes. Due to the world's uncertainties, creation and maintenance of navigation plans cannot involve arbitrarily complex processes, as the robot's perception of the world will be in constant flux, requiring modifications to be made quickly if they are to be of any use. This work introduces navigation templates (NaT's) which are building blocks for the construction and maintenance of rough navigation plans which capture the relationship that objects in the world have to the current navigation task. By encoding only the critical relationship between the objects in the world and the navigation task, a NaT-based navigation plan is highly flexible; allowing new constraints to be quickly incorporated into the plan and existing constraints to be updated or deleted from the plan. To satisfy the robot's need for immediate local guidance, the NaT's forming the current navigation plan are passed to a transformation function. The transformation function analyzes the plan with respect to the robot's current location to quickly determine (a few times a second) the locally preferred direction of travel. This dissertation presents NaT's and the transformation function as well as the needed support systems to demonstrate the usefulness of the technique for controlling the actions of a mobile robot operating in an uncertain world.

  15. FLASH LIDAR Based Relative Navigation

    NASA Technical Reports Server (NTRS)

    Brazzel, Jack; Clark, Fred; Milenkovic, Zoran

    2014-01-01

    Relative navigation remains the most challenging part of spacecraft rendezvous and docking. In recent years, flash LIDARs, have been increasingly selected as the go-to sensors for proximity operations and docking. Flash LIDARS are generally lighter and require less power that scanning Lidars. Flash LIDARs do not have moving parts, and they are capable of tracking multiple targets as well as generating a 3D map of a given target. However, there are some significant drawbacks of Flash Lidars that must be resolved if their use is to be of long-term significance. Overcoming the challenges of Flash LIDARs for navigation-namely, low technology readiness level, lack of historical performance data, target identification, existence of false positives, and performance of vision processing algorithms as intermediaries between the raw sensor data and the Kalman filter-requires a world-class testing facility, such as the Lockheed Martin Space Operations Simulation Center (SOSC). Ground-based testing is a critical step for maturing the next-generation flash LIDAR-based spacecraft relative navigation. This paper will focus on the tests of an integrated relative navigation system conducted at the SOSC in January 2014. The intent of the tests was to characterize and then improve the performance of relative navigation, while addressing many of the flash LIDAR challenges mentioned above. A section on navigation performance and future recommendation completes the discussion.

  16. Elevation scanning laser/multi-sensor hazard detection system controller and mirror/mast speed control components. [roving vehicle electromechanical devices

    NASA Technical Reports Server (NTRS)

    Craig, J.; Yerazunis, S. W.

    1978-01-01

    The electro-mechanical and electronic systems involved with pointing a laser beam from a roving vehicle along a desired vector are described. A rotating 8 sided mirror, driven by a phase-locked dc motor servo system, and monitored by a precision optical shaft encoder is used. This upper assembly is then rotated about an orthogonal axis to allow scanning into all 360 deg around the vehicle. This axis is also driven by a phase locked dc motor servo-system, and monitored with an optical shaft encoder. The electronics are realized in standard TTL integrated circuits with UV-erasable proms used to store desired coordinates of laser fire. Related topics such as the interface to the existing test vehicle are discussed.

  17. Parity bifurcations in trapped multistable phase locked exciton-polariton condensates

    NASA Astrophysics Data System (ADS)

    Tan, E. Z.; Sigurdsson, H.; Liew, T. C. H.

    2018-02-01

    We present a theoretical scheme for multistability in planar microcavity exciton-polariton condensates under nonresonant driving. Using an excitation profile resulting in a spatially patterned condensate, we observe organized phase locking which can abruptly reorganize as a result of pump induced instability made possible by nonlinear interactions. For π /2 symmetric systems this reorganization can be regarded as a parity transition and is found to be a fingerprint of multistable regimes existing over a finite range of excitation strengths. The natural degeneracy of the planar equations of motion gives rise to parity bifurcation points where the condensate, as a function of excitation intensity, bifurcates into one of two anisotropic degenerate solutions. Deterministic transitions between multistable states are made possible using controlled nonresonant pulses, perturbing the solution from one attractor to another.

  18. Mode locking and quasiperiodicity in a discrete-time Chialvo neuron model

    NASA Astrophysics Data System (ADS)

    Wang, Fengjuan; Cao, Hongjun

    2018-03-01

    The two-dimensional parameter spaces of a discrete-time Chialvo neuron model are investigated. Our studies demonstrate that for all our choice of two parameters (i) the fixed point is destabilized via Neimark-Sacker bifurcation; (ii) there exist mode locking structures like Arnold tongues and shrimps, with periods organized in a Farey tree sequence, embedded in quasiperiodic/chaotic region. We determine analytically the location of the parameter sets where Neimark-Sacker bifurcation occurs, and the location on this curve where Arnold tongues of arbitrary period are born. Properties of the transition that follows the so-called two-torus from quasiperiodicity to chaos are presented clearly and proved strictly by using numerical simulations such as bifurcation diagrams, the largest Lyapunov exponent diagram on MATLAB and C++.

  19. Noncoherent pseudonoise code tracking performance of spread spectrum receivers

    NASA Technical Reports Server (NTRS)

    Simon, M. K.

    1977-01-01

    The optimum design and performance of two noncoherent PN tracking loop configurations, namely, the delay-locked loop and tau-dither loop, are described. In particular, the bandlimiting effects of the bandpass arm filters are considered by demonstrating that for a fixed data rate and data signal-to-noise ratio, there exists an optimum filter bandwidth in the sense of minimizing the loop's tracking jitter. Both the linear and nonlinear loop analyses are presented, and the region of validity of the former relative to the latter is indicated. In addition, numerical results are given for several filter types. For example, assuming ideal bandpass arm filters, it is shown that the tau-dither loop requires approximately 1 dB more signal-to-noise ratio than the delay-locked loop for equal rms tracking jitters.

  20. Dynamic rupture models of earthquakes on the Bartlett Springs Fault, Northern California

    USGS Publications Warehouse

    Lozos, Julian C.; Harris, Ruth A.; Murray, Jessica R.; Lienkaemper, James J.

    2015-01-01

    The Bartlett Springs Fault (BSF), the easternmost branch of the northern San Andreas Fault system, creeps along much of its length. Geodetic data for the BSF are sparse, and surface creep rates are generally poorly constrained. The two existing geodetic slip rate inversions resolve at least one locked patch within the creeping zones. We use the 3-D finite element code FaultMod to conduct dynamic rupture models based on both geodetic inversions, in order to determine the ability of rupture to propagate into the creeping regions, as well as to assess possible magnitudes for BSF ruptures. For both sets of models, we find that the distribution of aseismic creep limits the extent of coseismic rupture, due to the contrast in frictional properties between the locked and creeping regions.

  1. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking faces of mechanical locking; fit. 236.337... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit... face. ...

  2. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking faces of mechanical locking; fit. 236.337... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit... face. ...

  3. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking faces of mechanical locking; fit. 236.337... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit... face. ...

  4. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking faces of mechanical locking; fit. 236.337... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall fit... face. ...

  5. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  6. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  7. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  8. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  9. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  10. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial

    PubMed Central

    Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

    2014-01-01

    Objectives To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. Design A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. Setting 18 trauma centres in the United Kingdom. Participants 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Interventions Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. Main outcome measures Primary outcome measure: validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient’s experience of pain and disability to give a score out of 100. Secondary outcomes: disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. Results The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was −1.3, 95% confidence interval −4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Conclusions Contrary to the existing literature, and against the rapidly increasing use of locking plate fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Trial registration Current Controlled Trials ISCRTN 31379280. UKCRN 8956. PMID:25096595

  11. 41. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK LOCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. LOCK AND DAM NO. 26 (REPLACEMENT). LOCK -- LOCK GATES -- LIFT GATE, GATE LEAVES -- GENERAL ASSEMBLY. M-L 26(R) 21/28 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  12. An IMM-Aided ZUPT Methodology for an INS/DVL Integrated Navigation System.

    PubMed

    Yao, Yiqing; Xu, Xiaosu; Xu, Xiang

    2017-09-05

    Inertial navigation system (INS)/Doppler velocity log (DVL) integration is the most common navigation solution for underwater vehicles. Due to the complex underwater environment, the velocity information provided by DVL always contains some errors. To improve navigation accuracy, zero velocity update (ZUPT) technology is considered, which is an effective algorithm for land vehicles to mitigate the navigation error during the pure INS mode. However, in contrast to ground vehicles, the ZUPT solution cannot be used directly for underwater vehicles because of the existence of the water current. In order to leverage the strengths of the ZUPT method and the INS/DVL solution, an interactive multiple model (IMM)-aided ZUPT methodology for the INS/DVL-integrated underwater navigation system is proposed. Both the INS/DVL and INS/ZUPT models are constructed and operated in parallel, with weights calculated according to their innovations and innovation covariance matrices. Simulations are conducted to evaluate the proposed algorithm. The results indicate that the IMM-aided ZUPT solution outperforms both the INS/DVL solution and the INS/ZUPT solution in the underwater environment, which can properly distinguish between the ZUPT and non-ZUPT conditions. In addition, during DVL outage, the effectiveness of the proposed algorithm is also verified.

  13. Meta-analysis suggests that the electromagnetic technique is better than the free-hand method for the distal locking during intramedullary nailing procedures.

    PubMed

    Zhu, Yanbin; Chang, Hengrui; Yu, Yiyang; Chen, Wei; Liu, Song; Zhang, Yingze

    2017-05-01

    To evaluate the comparative effectiveness and accuracy of electromagnetic technique (EM) verses free-hand method (FH) for distal locking in intramedullary nailing procedure. Relevant original studies were searched in Medline, Pubmed, Embase, China National Knowledge Infrastructure, and Cochrane Central Database (all through October 2015). Comparative studies providing sufficient data of interest were included in this meta-analysis. The Stata 11.0 was used to analyze all data. Eight studies involving 611 participants were included, with 305 in EM group and 306 in FH group. EM outperformed FH with reduced distal locking time of 4.1 minutes [standardized mean difference (SMD), 1.61; 95 % confidence interval (95 %CI), 0.81 to 2.41] and the reduced fluoroscopy time of 25.3 seconds (SMD, 2.64; 95 %CI, 2.12 to 3.16). Regarding the accuracy of distal screw placement, no significant difference was observed between two techniques (OR, 2.39; 95 %CI, 0.38 to 15.0). There was a trend of longer operative time in FH versus EM by 10 minutes (79.0 and 69.0 minutes), although the difference was not statistically significant (SMD, 0.341; 95 % CI, -0.02 to 0.703). The existing evidence suggests EM technique is a better alternative for distal locking in intramedullary nailing procedure, and this might aid in the management of diaphyseal fractures in lower extremities.

  14. An estimate of post-depositional remanent magnetization lock-in depth in organic rich varved lake sediments

    NASA Astrophysics Data System (ADS)

    Snowball, Ian; Mellström, Anette; Ahlstrand, Emelie; Haltia, Eeva; Nilsson, Andreas; Ning, Wenxin; Muscheler, Raimund; Brauer, Achim

    2013-11-01

    We studied the paleomagnetic properties of relatively organic rich, annually laminated (varved) sediments of Holocene age in Gyltigesjön, which is a lake in southern Sweden. An age-depth model was based on a regional lead pollution isochron and Bayesian modelling of radiocarbon ages of bulk sediments and terrestrial macrofossils, which included a radiocarbon wiggle-matched series of 873 varves that accumulated between 3000 and 2000 Cal a BP (Mellström et al., 2013). Mineral magnetic data and first order reversal curves suggest that the natural remanent magnetization is carried by stable single-domain grains of magnetite, probably of magnetosomal origin. Discrete samples taken from overlapping piston cores were used to produce smoothed paleomagnetic secular variation (inclination and declination) and relative paleointensity data sets. Alternative temporal trends in the paleomagnetic data were obtained by correcting for paleomagnetic lock-in depths between 0 and 70 cm and taking into account changes in sediment accumulation rate. These temporal trends were regressed against reference curves for the same region (FENNOSTACK and FENNORPIS; Snowball et al., 2007). The best statistical matches to the reference curves are obtained when we apply lock-in depths of 21-34 cm to the Gyltigesjön paleomagnetic data, although these are most likely minimum estimates. Our study suggests that a significant paleomagnetic lock-in depth can affect the acquisition of post-depositional remanent magnetization even where bioturbation is absent and no mixed sediment surface layer exists.

  15. Pushing Past the Achievement Gap: An Essay on the Language of Deficit

    ERIC Educational Resources Information Center

    Ladson-Billings, Gloria

    2007-01-01

    Despite the intense focus on the achievement gap that exists between African American, Latino, and other students of color and their White counterparts, the achievement gap discourse keeps us locked in the deficit paradigm. This article challenges us to look at the inherent fallacies of the achievement gap discourse and place students' academic…

  16. Recognition and Mental Manipulation of Body Parts Dissociate in Locked-In Syndrome

    ERIC Educational Resources Information Center

    Conson, Massimiliano; Pistoia, Francesca; Sara, Marco; Grossi, Dario; Trojano, Luigi

    2010-01-01

    Several lines of evidence demonstrate that the motor system is involved in motor simulation of actions, but some uncertainty exists about the consequences of lesions of descending motor pathways on mental imagery tasks. Moreover, recent findings suggest that the motor system could also have a role in recognition of body parts. To address these…

  17. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. ...

  18. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. ...

  19. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Facing point lock or switch-and-lock movement. 236... Interlocking Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  20. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Facing point lock or switch-and-lock movement. 236... Interlocking Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

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