75 FR 51843 - In the Matter of Certain Large Scale Integrated Circuit Semiconductor Chips and Products...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-23

... Integrated Circuit Semiconductor Chips and Products Containing the Same; Notice of Commission Decision Not To... semiconductor chips and products containing same by reason of infringement of certain claims of U.S. Patent Nos. 5,933,364 and 6,834,336. The complaint further alleges the existence of a domestic industry. The...

Interagency Cooperation Commission Act

THOMAS, 111th Congress

Rep. Forbes, J. Randy [R-VA-4

2009-04-30

House - 06/26/2009 Referred to the Subcommittee on Government Management, Organization, and Procurement. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Corporate Subsidy Reform Commission Act

THOMAS, 111th Congress

Rep. Smith, Adam [D-WA-9

2010-05-26

House - 07/30/2010 Referred to the Subcommittee on Government Management, Organization, and Procurement. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Collaboration Act

THOMAS, 111th Congress

Rep. Stupak, Bart [D-MI-1

2009-12-01

House - 12/02/2009 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Congress 2014 Commission Act

THOMAS, 111th Congress

Rep. Hastings, Alcee L. [D-FL-23

2009-10-29

House - 01/04/2010 Referred to the Subcommittee on the Constitution, Civil Rights, and Civil Liberties. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Financial Markets Commission Act of 2009

THOMAS, 111th Congress

Rep. Delahunt, Bill [D-MA-10

2009-05-05

House - 06/22/2010 Referred to the Subcommittee on General Farm Commodities and Risk Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Global Online Freedom Act of 2011

THOMAS, 112th Congress

Rep. Smith, Christopher H. [R-NJ-4

2011-12-08

Senate - 10/19/2012 Committee on Commission on Security and Cooperation in Europe. Joint hearings held. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Trafficking Victims Protection Reauthorization Act of 2011

THOMAS, 112th Congress

Rep. Smith, Christopher H. [R-NJ-4

2011-08-30

Senate - 11/02/2011 Committee on Commission on Security and Cooperation in Europe. Hearings held. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Criminal Justice Commission Act of 2010

THOMAS, 111th Congress

Sen. Webb, Jim [D-VA

2009-03-26

Senate - 05/06/2010 Placed on Senate Legislative Calendar under General Orders. Calendar No. 369. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Criminal Justice Commission Act of 2013

THOMAS, 113th Congress

Rep. Deutch, Theodore E. [D-FL-21

2013-02-01

House - 02/28/2013 Referred to the Subcommittee on Crime, Terrorism, Homeland Security, And Investigations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Denali Commission Reauthorization Act of 2012

THOMAS, 112th Congress

Rep. Young, Don [R-AK-At Large

2012-09-20

House - 09/21/2012 Referred to the Subcommittee on Economic Development, Public Buildings and Emergency Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Pick-Sloan Tribal Commission Act of 2010

THOMAS, 111th Congress

Sen. Dorgan, Byron L. [D-ND

2010-07-26

Senate - 12/08/2010 Placed on Senate Legislative Calendar under General Orders. Calendar No. 680. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

78 FR 28628 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

... identified by name by the International Trade Commission as a member of a domestic industry in an... date 82,509 Hemlock Semiconductor Corporation, Hemlock, MI......... February 27, 2012. Dow Corning Corporation, Adecco, Qualified Staffing, SimplexGrennell LP. 82,509A Hemlock Semiconductor LLC, Dow...

Financial Product Safety Commission Act of 2009

THOMAS, 111th Congress

Sen. Durbin, Richard J. [D-IL

2009-03-10

Senate - 03/10/2009 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Eliminate the Commission to Nowhere Act of 2013

THOMAS, 113th Congress

Rep. Chabot, Steve [R-OH-1

2013-11-21

House - 11/22/2013 Referred to the Subcommittee on Economic Development, Public Buildings and Emergency Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Diabetes Clinical Care Commission Act

THOMAS, 112th Congress

Sen. Shaheen, Jeanne [D-NH

2012-07-25

Senate - 07/25/2012 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Diabetes Clinical Care Commission Act

THOMAS, 113th Congress

Sen. Shaheen, Jeanne [D-NH

2013-03-12

Senate - 03/12/2013 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Evidence-Based Policymaking Commission Act of 2014

THOMAS, 113th Congress

Sen. Murray, Patty [D-WA

2014-11-20

Senate - 11/20/2014 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Centennial Monetary Commission Act of 2013

THOMAS, 113th Congress

Sen. Cornyn, John [R-TX

2014-01-06

Senate - 01/06/2014 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Consolidated Reporting Act of 2013

THOMAS, 113th Congress

Sen. Heller, Dean [R-NV

2013-07-29

Senate - 07/29/2013 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Consolidated Reporting Act of 2011

THOMAS, 112th Congress

Sen. Heller, Dean [R-NV

2011-11-02

Senate - 11/02/2011 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Military Commissions Habeas Corpus Restoration Act of 2009

THOMAS, 111th Congress

Rep. Jackson-Lee, Sheila [D-TX-18

2009-01-06

House - 02/09/2009 Referred to the Subcommittee on the Constitution, Civil Rights, and Civil Liberties. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Fannie Mae and Freddie Mac Investigative Commission Act

THOMAS, 112th Congress

Rep. Kaptur, Marcy [D-OH-9

2011-06-02

House - 07/29/2011 Referred to the Subcommittee on Capital Markets and Government Sponsored Enterprises. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on the Accountability and Review of Federal Agencies Act

THOMAS, 111th Congress

Rep. Tiahrt, Todd [R-KS-4

2009-03-30

House - 05/04/2009 Referred to the Subcommittee on Government Management, Organization, and Procurement. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Civil War Sesquicentennial Commission Act

THOMAS, 112th Congress

Rep. Jackson, Jesse L., Jr. [D-IL-2

2011-04-07

House - 04/08/2011 Referred to the Subcommittee on Federal Workforce, U.S. Postal Service, and Labor Policy . (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Educational Opportunity and Equity Commission Act of 2009

THOMAS, 111th Congress

Rep. Honda, Michael M. [D-CA-15

2009-03-26

House - 05/14/2009 Referred to the Subcommittee on Early Childhood, Elementary, and Secondary Education. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Commission on Federal Marijuana Policy Act of 2013

THOMAS, 113th Congress

Rep. Cohen, Steve [D-TN-9

2013-04-18

House - 04/30/2013 Referred to the Subcommittee on Crime, Terrorism, Homeland Security, and Investigations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Northern Border Regional Commission Reauthorization Act of 2013

THOMAS, 113th Congress

Rep. Michaud, Michael H. [D-ME-2

2013-02-28

House - 03/01/2013 Referred to the Subcommittee on Economic Development, Public Buildings and Emergency Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Financial Markets Commission Act of 2009

THOMAS, 111th Congress

Sen. Isakson, Johnny [R-GA

2009-01-22

Senate - 01/22/2009 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Collaboration Act of 2013

THOMAS, 113th Congress

Sen. Klobuchar, Amy [D-MN

2013-02-07

Senate - 02/07/2013 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Process Reform Act of 2014

THOMAS, 113th Congress

Sen. Heller, Dean [R-NV

2014-02-04

Senate - 02/04/2014 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Process Reform Act of 2011

THOMAS, 112th Congress

Sen. Heller, Dean [R-NV

2011-11-02

Senate - 11/02/2011 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Consumer Financial Protection Commission Act of 2014

THOMAS, 113th Congress

Sen. Fischer, Deb [R-NE

2014-04-03

Senate - 04/03/2014 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Star-Spangled Banner and War of 1812 Bicentennial Commission Act

THOMAS, 111th Congress

Sen. Cardin, Benjamin L. [D-MD

2009-03-03

Senate - 08/05/2010 Placed on Senate Legislative Calendar under General Orders. Calendar No. 549. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission to Study Reparation Proposals for African-Americans Act

THOMAS, 111th Congress

Rep. Conyers, John, Jr. [D-MI-14

2009-01-06

House - 02/09/2009 Referred to the Subcommittee on the Constitution, Civil Rights, and Civil Liberties. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Western Hemisphere Drug Policy Commission Act of 2014

THOMAS, 113th Congress

Rep. Engel, Eliot L. [D-NY-16

2014-05-09

House - 06/26/2014 Ordered to be Reported in the Nature of a Substitute (Amended) by Unanimous Consent. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Consumer Financial Protection Commission Act of 2013

THOMAS, 113th Congress

Rep. Duffy, Sean P. [R-WI-7

2013-06-17

House - 10/29/2013 Hearings Held by the Subcommittee on Financial Institutions and Consumer Credit Prior to Referral. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

United States Authorization and Sunset Commission Act of 2009

THOMAS, 111th Congress

Sen. Cornyn, John [R-TX

2009-04-29

Senate - 04/29/2009 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Criminal Justice Commission Act of 2010

THOMAS, 111th Congress

Rep. Delahunt, Bill [D-MA-10

2010-04-27

Senate - 08/05/2010 Read twice. Placed on Senate Legislative Calendar under General Orders. Calendar No. 514. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Presidential Commission on Women Act of 2009

THOMAS, 111th Congress

Rep. Speier, Jackie [D-CA-12

2009-04-02

House - 06/26/2009 Referred to the Subcommittee on Federal Workforce, Post Office, and the District of Columbia. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

St. Augustine 450th Commemoration Commission Act of 2009

THOMAS, 111th Congress

Rep. Mica, John L. [R-FL-7

2009-01-13

House - 02/24/2009 Referred to the Subcommittee on Federal Workforce, Post Office, and the District of Columbia. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Civil War Sesquicentennial Commission Act

THOMAS, 111th Congress

Sen. Landrieu, Mary L. [D-LA

2009-10-22

Senate - 12/03/2009 Committee on Energy and Natural Resources Subcommittee on National Parks. Hearings held. With printed Hearing: S.Hrg. 111-318. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Western Hemisphere Drug Policy Commission Act of 2009

THOMAS, 111th Congress

Rep. Engel, Eliot L. [D-NY-17

2009-04-28

Senate - 12/09/2009 Received in the Senate and Read twice and referred to the Committee on Foreign Relations. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

To establish a national commission on presidential war powers and civil liberties.

THOMAS, 111th Congress

Rep. Conyers, John, Jr. [D-MI-14

2009-01-06

House - 06/12/2009 Referred to the Subcommittee on the Constitution, Civil Rights, and Civil Liberties. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Wartime Relocation and Internment of Latin Americans of Japanese Descent Act

THOMAS, 111th Congress

Sen. Inouye, Daniel K. [D-HI

2009-01-06

Senate - 12/23/2009 Placed on Senate Legislative Calendar under General Orders. Calendar No. 250. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Measures of Household Economic Security Act of 2010

THOMAS, 111th Congress

Sen. Feingold, Russell D. [D-WI

2009-12-11

Senate - 12/11/2009 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission to Study the Potential Creation of a National Women's History Museum Act

THOMAS, 113th Congress

Sen. Collins, Susan M. [R-ME

2013-02-27

Senate - 12/10/2014 Placed on Senate Legislative Calendar under General Orders. Calendar No. 630. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Effective Regulation and Assessment Systems for Public Schools Act

THOMAS, 112th Congress

Sen. Bennet, Michael F. [D-CO

2011-03-17

Senate - 03/17/2011 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Effective Regulation and Assessment Systems for Public Schools Act

THOMAS, 113th Congress

Sen. Bennet, Michael F. [D-CO

2013-05-22

Senate - 05/22/2013 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Catastrophic Disaster Risk and Insurance Act of 2009

THOMAS, 111th Congress

Sen. Nelson, Bill [D-FL

2009-07-21

Senate - 07/21/2009 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Commission on Catastrophic Disaster Risk and Insurance Act of 2011

THOMAS, 112th Congress

Sen. Nelson, Bill [D-FL

2011-07-27

Senate - 07/27/2011 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Commission on Children and Disasters Reauthorization Act of 2010

THOMAS, 111th Congress

Sen. Dodd, Christopher J. [D-CT

2010-09-29

Senate - 09/29/2010 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Oceanic and Atmospheric Administration Commissioned Officer Corps Amendments Act of 2013

THOMAS, 113th Congress

Rep. Grayson, Alan [D-FL-9

2014-09-09

House - 09/26/2014 Referred to the Subcommittee on Crime, Terrorism, Homeland Security, and Investigations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Civil War Sesquicentennial Commission Act

THOMAS, 112th Congress

Sen. Webb, Jim [D-VA

2011-03-16

Senate - 05/11/2011 Committee on Energy and Natural Resources Subcommittee on National Parks. Hearings held. With printed Hearing: S.Hrg. 112-124. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Consolidated Reporting Act of 2013

THOMAS, 113th Congress

Rep. Scalise, Steve [R-LA-1

2013-07-26

Senate - 09/10/2013 Received in the Senate and Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Federal Communications Commission Consolidated Reporting Act of 2012

THOMAS, 112th Congress

Rep. Scalise, Steve [R-LA-1

2011-11-02

Senate - 06/04/2012 Received in the Senate and Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Commission on Wartime Relocation and Internment of Latin Americans of Japanese Descent Act

THOMAS, 112th Congress

Sen. Inouye, Daniel K. [D-HI

2011-01-25

Senate - 01/25/2011 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To authorize appropriations for the National Historical Publications and Records Commission through fiscal year 2014.

THOMAS, 111th Congress

Rep. Clay, Wm. Lacy [D-MO-1

2009-03-17

House - 05/04/2009 Referred to the Subcommittee on Information Policy, Census, and National Archives. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Federal Communications Commission Process Reform Act of 2014

THOMAS, 113th Congress

Rep. Walden, Greg [R-OR-2

2013-12-09

Senate - 03/12/2014 Received in the Senate and Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Federal Communications Commission Process Reform Act of 2012

THOMAS, 112th Congress

Rep. Walden, Greg [R-OR-2

2011-11-02

Senate - 03/28/2012 Received in the Senate and Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

A bill to establish a Commission on Congressional Budgetary Accountability and Review of Federal Agencies.

THOMAS, 112th Congress

Sen. Ensign, John [R-NV

2011-01-25

Senate - 01/25/2011 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to establish a Commission on Congressional Budgetary Accountability and Review of Federal Agencies.

THOMAS, 111th Congress

Sen. Brownback, Sam [R-KS

2009-06-17

Senate - 06/17/2009 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to require a report by the Federal Communications Commission on designated market areas.

THOMAS, 113th Congress

Sen. Booker, Cory A. [D-NJ

2014-07-22

Senate - 07/22/2014 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To improve public participation and overall decision-making at the Federal Communications Commission, and for other purposes.

THOMAS, 111th Congress

Rep. Barton, Joe [R-TX-6

2009-04-30

House - 05/04/2009 Referred to the Subcommittee on Communications, Technology, and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

77 FR 39510 - Certain Semiconductor Integrated Circuit Devices and Products Containing Same; Determination Not...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-03

..., 500 E Street SW., Washington, DC 20436, telephone (202) 708-2301. Copies of non- confidential... Commission, 500 E Street SW., Washington, DC 20436, telephone (202) 205-2000. General information concerning... Rules of Practice and Procedure (19 CFR 210.42). By order of the Commission. Issued: June 27, 2012. Lisa...

To require the Commodity Futures Trading Commission to take certain actions to reduce excessive speculation in energy markets.

THOMAS, 112th Congress

Rep. Hinchey, Maurice D. [D-NY-22

2012-04-19

House - 05/10/2012 Referred to the Subcommittee on General Farm Commodities and Risk Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To reauthorize the Delaware Water Gap National Recreation Area Citizen Advisory Commission.

THOMAS, 111th Congress

Rep. Garrett, Scott [R-NJ-5

2009-07-31

Senate - 10/14/2009 Received in the Senate and Read twice and referred to the Committee on Energy and Natural Resources. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

To require the Commodity Futures Trading Commission to take certain actions to reduce excessive speculation in energy markets.

THOMAS, 112th Congress

Rep. Hochul, Kathleen C. [D-NY-26

2012-04-18

House - 05/10/2012 Referred to the Subcommittee on General Farm Commodities and Risk Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Commission on Children and Disasters Reauthorization Act of 2010

THOMAS, 111th Congress

Rep. Brown, Corrine [D-FL-3

2010-05-11

Senate - 07/21/2010 Received in the Senate and Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

A bill to require the Commodity Futures Trading Commission to take certain actions to reduce excessive speculation in energy markets.

THOMAS, 112th Congress

Sen. Sanders, Bernard [I-VT

2012-03-21

Senate - 03/21/2012 Read twice and referred to the Committee on Agriculture, Nutrition, and Forestry. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Deployment of the Hobby-Eberly Telescope wide-field upgrade

NASA Astrophysics Data System (ADS)

Hill, Gary J.; Drory, Niv; Good, John M.; Lee, Hanshin; Vattiat, Brian L.; Kriel, Herman; Ramsey, Jason; Bryant, Randy; Elliot, Linda; Fowler, Jim; Häuser, Marco; Landiau, Martin; Leck, Ron; Odewahn, Stephen; Perry, Dave; Savage, Richard; Schroeder Mrozinski, Emily; Shetrone, Matthew; DePoy, D. L.; Prochaska, Travis; Marshall, J. L.; Damm, George; Gebhardt, Karl; MacQueen, Phillip J.; Martin, Jerry; Armandroff, Taft; Ramsey, Lawrence W.

2016-07-01

The Hobby-Eberly Telescope (HET) is an innovative large telescope, located in West Texas at the McDonald Observatory. The HET operates with a fixed segmented primary and has a tracker, which moves the four-mirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. We have completed a major multi-year upgrade of the HET that has substantially increased the pupil size to 10 meters and the field of view to 22 arcminutes by replacing the corrector, tracker, and prime focus instrument package. The new wide field HET will feed the revolutionary integral field spectrograph called VIRUS, in support of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX§), a new low resolution spectrograph (LRS2), an upgraded high resolution spectrograph (HRS2), and later the Habitable Zone Planet Finder (HPF). The upgrade is being commissioned and this paper discusses the completion of the installation, the commissioning process and the performance of the new HET.

To give subpoena power to the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling.

THOMAS, 111th Congress

Rep. Capps, Lois [D-CA-23

2010-06-08

Senate - 06/25/2010 Read the second time. Placed on Senate Legislative Calendar under General Orders. Calendar No. 442. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

A bill to require the Commodity Futures Trading commission to take certain emergency action to eliminate excessive speculation in energy markets.

THOMAS, 113th Congress

Sen. Sanders, Bernard [I-VT

2014-06-26

Senate - 06/26/2014 Read twice and referred to the Committee on Agriculture, Nutrition, and Forestry. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To amend title 40, United States Code, to eliminate the leasing authority of the Securities and Exchange Commission, and for other purposes.

THOMAS, 112th Congress

Rep. Norton, Eleanor Holmes [D-DC-At Large

2011-06-24

House - 06/27/2011 Referred to the Subcommittee on Economic Development, Public Buildings and Emergency Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

National Manufacturing Strategy: Is a National Manufacturing Strategy Essential to National Security?

DTIC Science & Technology

2011-05-01

cycle found nearly a quarter of all homeowners owning more than their home was worth. 11 Both Paul Volcker and Warren Buffet arrived at similar...November 15, 2010; Warren Buffet , Testimony, Financial Crisis Inquiry Commission, June 2, 2010; “Subprime Mortgage Crisis,” http://en.wikipedia.org...overseas manufacturing. Case Study: Semiconductor Wafer Industry. The history of the semiconductor industry is an instructive account . It begins with

To authorize the Secretary of Homeland Security to provide to owners of certain intellectual property rights information on, and unredacted samples and images of, semiconductor chip products suspected of being imported in violation of the rights of the owner of a registered mark or the owner of a mask work.

THOMAS, 112th Congress

Rep. McCaul, Michael T. [R-TX-10

2012-06-21

House - 07/11/2012 Referred to the Subcommittee on Intellectual Property, Competition and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to require publicly traded coal companies to include certain safety records in their reports to the Commission, and for other purposes.

THOMAS, 111th Congress

Sen. Rockefeller, John D., IV [D-WV

2010-05-27

Senate - 05/27/2010 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A joint resolution to consent to certain amendments enacted by the legislature of the State of Hawaii to the Hawaiian Homes Commission, Act, 1920.

THOMAS, 113th Congress

Sen. Schatz, Brian [D-HI

2013-03-21

Senate - 07/15/2013 Placed on Senate Legislative Calendar under General Orders. Calendar No. 133. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Disapproving the rule submitted by the Federal Communications Commission with respect to regulating the Internet and broadband industry practices.

THOMAS, 112th Congress

Rep. Walden, Greg [R-OR-2

2011-02-16

Senate - 04/13/2011 Read the second time. Placed on Senate Legislative Calendar under General Orders. Calendar No. 34. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

A bill to provide for a study by the National Academy of Sciences on the technical policy decisions and technical personnel at the Federal Communications Commission.

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2010-02-25

Senate - 02/25/2010 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Alyce Spotted Bear and Walter Soboleff Commission on Native Children Act

THOMAS, 113th Congress

Sen. Heitkamp, Heidi [D-ND

2013-10-30

Senate - 10/01/2014 By Senator Tester from Committee on Indian Affairs filed written report under authority of the order of the Senate of 09/18/2014. Report No. 113-264. Additional views filed. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

To reduce Federal spending and the deficit by terminating taxpayer financing of presidential election campaigns and party conventions and by terminating the Election Assistance Commission.

THOMAS, 112th Congress

Rep. Harper, Gregg [R-MS-3

2011-11-17

Senate - 12/05/2011 Received in the Senate and Read twice and referred to the Committee on Rules and Administration. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

A joint resolution disapproving the rule submitted by the Federal Communications Commission with respect to regulating the Internet and broadband industry practices.

THOMAS, 112th Congress

Sen. Hutchison, Kay Bailey [R-TX

2011-02-16

Senate - 11/10/2011 Motion to proceed to consideration of measure rejected in Senate by Yea-Nay Vote. 46 - 52. Record Vote Number: 200. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

United States Commission on International Religious Freedom Reform and Reauthorization Act of 2011

THOMAS, 112th Congress

Sen. Lee, Mike [R-UT

2011-11-15

Senate - 11/15/2011 Read twice and referred to the Committee on Foreign Relations. (All Actions) Notes: For further action, see H.R.2867, which became Public Law 112-75 on 12/23/2011. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to amend the Chesapeake and Ohio Canal Development Act to extend to the Chesapeake and Ohio Canal National Historical Park Commission.

THOMAS, 112th Congress

Sen. Cardin, Benjamin L. [D-MD

2011-02-10

Senate - 07/28/2011 Committee on Energy and Natural Resources Subcommittee on National Parks. Hearings held. With printed Hearing: S.Hrg. 112-214. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to clarify terms of cooperation between the Consumer Product Safety Commission and foreign government agencies in order to improve safety of imported products, and for other purposes.

THOMAS, 113th Congress

Sen. McCaskill, Claire [D-MO

2013-12-20

Senate - 12/20/2013 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

United States Commission on International Religious Freedom Reform and Reauthorization Act of 2014

THOMAS, 113th Congress

Sen. Durbin, Richard J. [D-IL

2014-07-30

Senate - 07/30/2014 Read twice and referred to the Committee on Foreign Relations. (All Actions) Notes: For further action, see H.R.5816, which became Public Law 113-271 on 12/18/2014. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

A bill to require the Comptroller General of the United States to submit a report to Congress on the effectiveness of the Federal Communications Commission's universal service reforms.

THOMAS, 113th Congress

Sen. Begich, Mark [D-AK

2013-04-22

Senate - 04/22/2013 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Mapping forest canopy disturbance in the Upper Great Lakes, USA

Treesearch

James D. Garner; Mark D. Nelson; Brian G. Tavernia; Charles H. (Hobie) Perry; Ian W. Housman

2015-01-01

A map of forest canopy disturbance was generated for Michigan, Wisconsin, and most of Minnesota using 42 Landsat time series stacks (LTSS) and a vegetation change tracker (VCTw) algorithm. Corresponding winter imagery was used to reduce commission errors of forest disturbance by identifying areas of persistent snow cover. The resulting disturbance age map was classed...

Providing for consideration of the bill (S. 627) to establish the Commission on Freedom of Information Act Processing Delays, and for other purposes.

THOMAS, 112th Congress

Rep. Dreier, David [R-CA-26

2011-07-27

House - 07/28/2011 On agreeing to the resolution Agreed to by the Yeas and Nays: 238 - 186 (Roll no. 663). (All Actions) Tracker: This bill has the status Agreed to in HouseHere are the steps for Status of Legislation:

United States Commission on International Religious Freedom Reauthorization Act of 2014

THOMAS, 113th Congress

Rep. Wolf, Frank R. [R-VA-10

2014-05-09

Senate - 07/09/2014 Received in the Senate and Read twice and referred to the Committee on Foreign Relations. (All Actions) Notes: For further action, see H.R.5816, which became Public Law 113-271 on 12/18/2014. Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

To amend the Chesapeake and Ohio Canal Development Act to extend to the Chesapeake and Ohio Canal National Historical Park Commission.

THOMAS, 113th Congress

Rep. Van Hollen, Chris [D-MD-8

2013-06-04

House - 06/10/2013 Referred to the Subcommittee on Public Lands and Environmental Regulation. (All Actions) Notes: For further action, see S.476, which became Public Law 113-178 on 9/26/2014. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Social Security Commission Act of 2014

THOMAS, 113th Congress

Rep. Delaney, John K. [D-MD-6

2014-05-30

House - 05/30/2014 Referred to the Committee on Ways and Means, and in addition to the Committee on Rules, for a period to be subsequently determined by the Speaker, in each case for consideration of such provisions as fall within the jurisdiction of the committee concerned. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Status of the KLOE-2 experiment

NASA Astrophysics Data System (ADS)

Di Cicco, Alessandro

2015-06-01

The KLOE-2 experiment at the Frascati National Laboratory of the INFN is undergoing commissioning, together with the e+e- collider DAΦNE. The KLOE apparatus, consisting of a huge Drift Chamber and an Electromagnetic Colorimeter working in a 0.5 T axial magnetic field, has been upgraded with the insertion of an Inner Tracker, two low-angle calorimeters (CCALT and QCALT) and low-angle taggers (LET and HET) for γγ-physics. Cosmic-ray muon and collision data are being acquired in order to optimize the sub-detectors operation in view of the new data taking campaign. The first results from the ongoing commissioning of the KLOE-2 detector will be shown.

77 FR 33240 - Certain Semiconductor Chips With DRAM Circuitry, and Modules and Products Containing Same...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... viewed on the Commission's electronic docket (EDIS) at http://edis.usitc.gov . Hearing-impaired persons... December 21, 2011, based on a complaint filed by Elpida Memory, Inc. of Tokyo, Japan and Elpida Memory (USA...

Frequency scanning interferometry in ATLAS: remote, multiple, simultaneous and precise distance measurements in a hostile environment

NASA Astrophysics Data System (ADS)

Coe, P. A.; Howell, D. F.; Nickerson, R. B.

2004-11-01

ATLAS is the largest particle detector under construction at CERN Geneva. Frequency scanning interferometry (FSI), also known as absolute distance interferometry, will be used to monitor shape changes of the SCT (semiconductor tracker), a particle tracker in the inaccessible, high radiation environment at the centre of ATLAS. Geodetic grids with several hundred fibre-coupled interferometers (30 mm to 1.5 m long) will be measured simultaneously. These lengths will be measured by tuning two lasers and comparing the resulting phase shifts in grid line interferometers (GLIs) with phase shifts in a reference interferometer. The novel inexpensive GLI design uses diverging beams to reduce sensitivity to misalignment, albeit with weaker signals. One micrometre precision length measurements of grid lines will allow 10 µm precision tracker shape corrections to be fed into ATLAS particle tracking analysis. The technique was demonstrated by measuring a 400 mm interferometer to better than 400 nm and a 1195 mm interferometer to better than 250 nm. Precise measurements were possible, even with poor quality signals, using numerical analysis of thousands of intensity samples. Errors due to drifts in interferometer length were substantially reduced using two lasers tuned in opposite directions and the precision was further improved by linking measurements made at widely separated laser frequencies.

76 FR 72214 - Certain Semiconductor Chips with DRAM Circuitry, and Modules and Products Containing Same Receipt...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-22

...://edis.usitc.gov . Hearing-impaired persons are advised that information on this matter can be obtained... Commission has received a complaint filed on behalf of Elpida Memory, Inc. and Elpida Memory (USA) Inc. on...

Commission on the Accountability and Review of Federal Agencies Act

THOMAS, 113th Congress

Rep. Collins, Doug [R-GA-9

2014-05-06

House - 05/06/2014 Referred to the Committee on Oversight and Government Reform, and in addition to the Committee on Rules, for a period to be subsequently determined by the Speaker, in each case for consideration of such provisions as fall within the jurisdiction of the committee... (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

CO2 evaporative cooling: The future for tracking detector thermal management

NASA Astrophysics Data System (ADS)

Tropea, P.; Daguin, J.; Petagna, P.; Postema, H.; Verlaat, B.; Zwalinski, L.

2016-07-01

In the last few years, CO2 evaporative cooling has been one of the favourite technologies chosen for the thermal management of tracking detectors at LHC. ATLAS Insertable B-Layer and CMS Pixel phase 1 upgrade have adopted it and their systems are now operational or under commissioning. The CERN PH-DT team is now merging the lessons learnt on these two systems in order to prepare the design and construction of the cooling systems for the new Upstream Tracker and the Velo upgrade in LHCb, due by 2018. Meanwhile, the preliminary design of the ATLAS and CMS full tracker upgrades is started, and both concepts heavily rely on CO2 evaporative cooling. This paper highlights the performances of the systems now in operation and the challenges to overcome in order to scale them up to the requirements of the future generations of trackers. In particular, it focuses on the conceptual design of a new cooling system suited for the large phase 2 upgrade programmes, which will be validated with the construction of a common prototype in the next years.

To amend a provision of the Securities Act of 1933 directing the Securities and Exchange Commission to add a particular class of securities to those exempted under such Act to provide a deadline for such action.

THOMAS, 113th Congress

Rep. McHenry, Patrick T. [R-NC-10

2013-02-14

Senate - 05/16/2013 Received in the Senate and Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

77 FR 26789 - Certain Semiconductor Chips Having Synchronous Dynamic Random Access Memory Controllers and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-07

... patents. 73 FR 75131. The principal respondent was NVIDIA Corporation of Santa Clara, California (``NVIDIA''). Joining NVIDIA as respondents were approximately twenty of NVIDIA's customers. The Commission found a... accused products in the United States: NVIDIA; Hewlett-Packard Co. of Palo Alto, California; ASUS Computer...

Search for WW and WZ production in lepton, neutrino plus jets final states at CDF Run II and Silicon module production and detector control system for the ATLAS SemiConductor Tracker

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

Sfyrla, Anna

2008-03-10

In the first part of this work, we present a search for WW and WZ production in charged lepton, neutrino plus jets final states produced in pmore » $$\\bar{p}$$ collisions with √s = 1.96 TeV at the Fermilab Tevatron, using 1.2 fb -1 of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large singleWplus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings that manifest themselves at higher transverse W momentum. Because the final state is topologically similar to associated production of a Higgs boson with a W, the techniques developed in this analysis are also applicable in that search. An Artificial Neural Network has been used for the event selection optimization. The theoretical prediction for the cross section is σ WW/WZ theory x Br(W → ℓv; W/Z → jj) = 2.09 ± 0.14 pb. They measured N Signal = 410 ± 212(stat) ± 102(sys) signal events that correspond to a cross section σ WW/WZ x Br(W → ℓv; W/Z → jj) = 1.47 ± 0.77(stat) ± 0.38(sys) pb. The 95% CL upper limit to the cross section is estimated to be σ x Br(W → ℓv; W/Z → jj) < 2.88 pb. The second part of the present work is technical and concerns the ATLAS SemiConductor Tracker (SCT) assembly phase. Although technical, the work in the SCT assembly phase is of prime importance for the good performance of the detector during data taking. The production at the University of Geneva of approximately one third of the silicon microstrip end-cap modules is presented. This collaborative effort of the university of Geneva group that lasted two years, resulted in 655 produced modules, 97% of which were good modules, constructed within the mechanical and electrical specifications and delivered in the SCT collaboration for assembly on the end-cap disks. The SCT end-caps and barrels consist of 4088 silicon modules, with a total of 6.3 million readout channels. The coherent and safe operation of the SCT during commissioning and subsequent operation is the essential task of the Detector Control System (DCS). The main building blocks of the DCS are the cooling system, the power supplies and the environmental system. The DCS has been initially developed for the SCT assembly phase and this system is described in the present work. Particular emphasis is given in the environmental hardware and software components, that were my major contributions. Results from the DCS testing during the assembly phase are also reported.« less

76 FR 5412 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-31

...); ISE Semiconductors (BYT); ISE Electronic Trading (DMA); ISE-Revere Natural Gas (FUM); ISE Water (HHO... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-63761; File No. SR-ISE-2011-04] Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing of Proposed Rule Change To Establish a...

HVMUX, a high voltage multiplexing for the ATLAS Tracker upgrade

NASA Astrophysics Data System (ADS)

Giulio Villani, E.; Phillips, P.; Matheson, J.; Zhang, Z.; Lynn, D.; Kuczewski, P.; Hommels, L. B. A.; Gregor, I.; Bessner, M.; Tackmann, K.; Newcomer, F. M.; Spencer, E.; Greenall, A.

2017-01-01

The HV biasing solution adopted in the current ATLAS detector uses one HV conductor for each sensor. This approach easily allows disabling of malfunctioning sensors without affecting the others, but space constraints and material budget considerations renders this approach impractical for the Upgraded detector. In fact, the increased luminosity of the Upgraded LHC will require more channels in the upgraded ATLAS Tracker, as a result of the finer detector segmentation. Different approaches to bring the HV biasing to the detectors, including the use of a shared HV line to bias several sensors and employing semiconductor switches for the HV routing (HVMUX), have been investigated. Beside the size constraints, particular attention must be paid to the radiation tolerance of any proposed solution, which, for the strips detector, requires proper operation up to fluences of the order of 2ṡ 1015 1MeV neq/cm2 and TID in excess of 300 kGy. In this paper, a description of the proposed HVMUX solution, along with electrical and radiation tests results will be presented and discussed.

Hobby-Eberly Telescope: commissioning experience and observing plans

NASA Astrophysics Data System (ADS)

Glaspey, John W.; Adams, M. T.; Booth, John A.; Cornell, Mark E.; Fowler, James R.; Krabbendam, Victor L.; Ramsey, Lawrence W.; Ray, Frank B.; Ricklefs, Randall L.; Spiesman, W. J.

1998-07-01

Experience in bringing into operation the 91-segment primary mirror alignment and control system, the focal plane tracker system, and other critical subsystems of the HET will be described. Particular attention is given to the tracker, which utilizes three linear and three rotational degrees of freedom to follow sidereal targets. Coarse time-dependent functions for each axis are downloaded to autonomous PMAC controllers that provide the precise motion drives to the two linear stages and the hexapod system. Experience gained in aligning the sperate mirrors and then maintaining image quality in a variable thermal environments will also be described. Because of the fixed elevation of the primary optical axis, only a limited amount of time is available for observing objects in the 12 degrees wide observing band. With a small core HET team working with McDonald Observatory staff, efficient, reliable, uncomplicated methodologies are required in all aspects of the observing operations.

To reduce Federal spending and the deficit by terminating taxpayer financing of presidential election campaigns and party conventions and by terminating the Election Assistance Commission.

THOMAS, 113th Congress

Rep. Harper, Gregg [R-MS-3

2013-01-15

House - 01/15/2013 Referred to the Committee on House Administration, and in addition to the Committee on Ways and Means, for a period to be subsequently determined by the Speaker, in each case for consideration of such provisions as fall within the jurisdiction of the committee... (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

NASA Astrophysics Data System (ADS)

Rivetti, Angelo

2014-11-01

In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8-10 bit resolution, 50-100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

Angle-depended photocurrent characteristics of cascade photoelectric converters on the base of homogeneous semiconductor

NASA Astrophysics Data System (ADS)

Arbuzov, Yuri D.; Evdokimov, Vladimir M.; Shepovalova, Olga V.

2018-05-01

Angle-dependent spectral photoresponse characteristics for theoretically perfect and physically implementable tunnel cascade (multi-junction) photoelectric converters (PC), for example high-voltage planar PV cells, have been studied as functions of technological parameters and number of single PCs in cascade. Angle-dependent spectral photoresponse characteristics values for real cascade silicon structures have been determined in visible and ultraviolet radiation spectra. Characteristic values of radiation incidence angle corresponding to the twofold photocurrent reduction in relation to normal incidence have been found depending on the number of single PCs in cascade, `dead' layer thickness of tunnel junction and photosensitivity of the base PC. The possibility and practicability of solar trackers use in PV systems with proposed PCs under study have been evaluated.

An on-line acoustic fluorocarbon coolant mixture analyzer for the ATLAS silicon tracker

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

Bates, R.; Battistin, M.; Berry, S.

2011-07-01

The ATLAS silicon tracker community foresees an upgrade from the present octafluoro-propane (C{sub 3}F{sub 8}) evaporative cooling fluid - to a composite fluid with a probable 10-20% admixture of hexafluoro-ethane (C{sub 2}F{sub 6}). Such a fluid will allow a lower evaporation temperature and will afford the tracker silicon substrates a better safety margin against leakage current-induced thermal runaway caused by cumulative radiation damage as the luminosity profile at the CERN Large Hadron Collider increases. Central to the use of this new fluid is a new custom-developed speed-of-sound instrument for continuous real-time measurement of the C{sub 3}F{sub 8}/C{sub 2}F{sub 6} mixturemore » ratio and flow. An acoustic vapour mixture analyzer/flow meter with new custom electronics allowing ultrasonic frequency transmission through gas mixtures has been developed for this application. Synchronous with the emission of an ultrasound 'chirp' from an acoustic transmitter, a fast readout clock (40 MHz) is started. The clock is stopped on receipt of an above threshold sound pulse at the receiver. Sound is alternately transmitted parallel and anti-parallel with the vapour flow for volume flow measurement from transducers that can serve as acoustic transmitters or receivers. In the development version, continuous real-time measurement of C{sub 3}F{sub 8}/C{sub 2}F{sub 6} flow and calculation of the mixture ratio is performed within a graphical user interface developed in PVSS-II, the Supervisory, Control and Data Acquisition standard chosen for LHC and its experiments at CERN. The described instrument has numerous potential applications - including refrigerant leak detection, the analysis of hydrocarbons, vapour mixtures for semiconductor manufacture and anesthetic gas mixtures. (authors)« less

An On-Line Acoustic Fluorocarbon Coolant Mixture Analyzer for the ATLAS Silicon Tracker

NASA Astrophysics Data System (ADS)

Bates, R.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Bousson, N.; Boyd, G.; Botelho-Direito, J.; DiGirolamo, B.; Doubek, M.; Egorov, K.; Godlewski, J.; Hallewell, G.; Katunin, S.; Mathieu, M.; McMahon, S.; Nagai, K.; Perez-Rodriguez, E.; Rozanov, A.; Vacek, V.; Vitek, M.

2012-10-01

The ATLAS silicon tracker community foresees an upgrade from the present octafluoropropane (C3F8) evaporative cooling fluid to a composite fluid with a probable 10-20% admixture of hexafluoroethane (C2F6). Such a fluid will allow a lower evaporation temperature and will afford the tracker silicon substrates a better safety margin against leakage current-induced thermal runaway caused by cumulative radiation damage as the luminosity profile at the CERN Large Hadron Collider increases. Central to the use of this new fluid is a new custom-developed speed-of-sound instrument for continuous real-time measurement of the C3F8/C2F6 mixture ratio and flow. An acoustic vapour mixture analyzer/flow meter with new custom electronics allowing ultrasonic frequency transmission through gas mixtures has been developed for this application. Synchronous with the emission of an ultrasound `chirp' from an acoustic transmitter, a fast readout clock (40 MHz) is started. The clock is stopped on receipt of an above threshold sound pulse at the receiver. Sound is alternately transmitted parallel and anti-parallel with the vapour flow for volume flow measurement from transducers that can serve as acoustic transmitters or receivers. In the development version, continuous real-time measurement of C3F8/C2F6 flow and calculation of the mixture ratio is performed within a graphical user interface developed in PVSS-II, the Supervisory, Control and Data Acquisition standard chosen for LHC and its experiments at CERN. The described instrument has numerous potential applications - including refrigerant leak detection, the analysis of hydrocarbons, vapour mixtures for semi-conductor manufacture and anesthetic gas mixtures.

Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

NASA Astrophysics Data System (ADS)

Poley, L.; Bloch, I.; Edwards, S.; Friedrich, C.; Gregor, I.-M.; Jones, T.; Lacker, H.; Pyatt, S.; Rehnisch, L.; Sperlich, D.; Wilson, J.

2016-05-01

The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive used initially between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). However, this glue has several disadvantages, which motivated the search for an alternative. This paper presents a study of six ultra-violet (UV) cure glues and a glue pad for possible use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, thermal conduction and shear strength. Samples were thermally cycled, radiation hardness and corrosion resistance were also determined. These investigations led to the exclusion of three UV cure glues as well as the glue pad. Three UV cure glues were found to be possible better alternatives than silver loaded glue. Results from electrical tests of first prototype modules constructed using these glues are presented.

Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam

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

ATLAS Collaboration; Ahmad, A.; Andreazza, A.

2008-06-02

A small set of final prototypes of the ATLAS Inner Detector silicon tracking system(Pixel Detector and SemiConductor Tracker), were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained inmore » the alignmentof the silicon modules is of the order of 5 mm in their most precise coordinate.« less

Global Precipitation Measurement Mission Launch and Commissioning

NASA Technical Reports Server (NTRS)

Davis, Nikesha; DeWeese, Keith; Vess, Melissa; O'Donnell, James R., Jr.; Welter, Gary

2015-01-01

During launch and early operation of the Global Precipitation Measurement (GPM) Mission, the Guidance, Navigation, and Control (GN&C) analysis team encountered four main on-orbit anomalies. These include: (1) unexpected shock from Solar Array deployment, (2) momentum buildup from the Magnetic Torquer Bars (MTBs) phasing errors, (3) transition into Safehold due to albedo induced Course Sun Sensor (CSS) anomaly, and (4) a flight software error that could cause a Safehold transition due to a Star Tracker occultation. This paper will discuss ways GN&C engineers identified the anomalies and tracked down the root causes. Flight data and GN&C on-board models will be shown to illustrate how each of these anomalies were investigated and mitigated before causing any harm to the spacecraft. On May 29, 2014, GPM was handed over to the Mission Flight Operations Team after a successful commissioning period. Currently, GPM is operating nominally on orbit, collecting meaningful scientific data that will significantly improve our understanding of the Earth's climate and water cycle.

A resolution expressing the sense of the Senate that, at the 21st Regular Meeting of the International Commission on the Conservation of Atlantic Tunas, the United States should seek to ensure management of the eastern Atlantic and Mediterranean bluefin tuna fishery adheres to the scientific advice provided by the Standing Committee on Research and Statistics and has a high probability of achieving the established rebuilding target, pursue strengthened protections for spawning bluefin populations in the Mediterranean Sea to facilitate the recovery of the Atlantic bluefin tuna, pursue imposition of more stringent measures to ensure compliance by all Members with the International Commission for the Conservation of Atlantic Tunas' conservation and management recommendations for Atlantic bluefin tuna and other species, and ensure that United States' quotas of tuna and swordfish are not reallocated to other nations, and for other purposes.

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2009-11-09

Senate - 11/09/2009 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

Global Precipitation Measurement Mission Launch and Commissioning

NASA Technical Reports Server (NTRS)

Davis, Nikesha; Deweese, Keith; Vess, Missie; Welter, Gary; O'Donnell, James R., Jr.

2015-01-01

During launch and early operation of the Global Precipitation Measurement (GPM) Mission, the Guidance, Navigation and Control (GNC) analysis team encountered four main on orbit anomalies. These include: (1) unexpected shock from Solar Array deployment, (2) momentum buildup from the Magnetic Torquer Bars (MTBs) phasing errors, (3) transition into Safehold due to albedo-induced Course Sun Sensor (CSS) anomaly, and (4) a flight software error that could cause a Safehold transition due to a Star Tracker occultation. This paper will discuss ways GNC engineers identified and tracked down the root causes. Flight data and GNC on board models will be shown to illustrate how each of these anomalies were investigated and mitigated before causing any harm to the spacecraft. On May 29, 2014, GPM was handed over to the Mission Flight Operations Team after a successful commissioning period. Currently, GPM is operating nominally on orbit, collecting meaningful scientific data that will significantly improve our understanding of the Earth's climate and water cycle.

Operation of Grid-tied 5 kWDC solar array to develop Laboratory Experiments for Solar PV Energy System courses

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

Ramos, Jaime

2012-12-14

To unlock the potential of micro grids we plan to build, commission and operate a 5 kWDC PV array and integrate it to the UTPA Engineering building low voltage network, as a micro grid; and promote community awareness. Assisted by a solar radiation tracker providing on-line information of its measurements and performing analysis for the use by the scientific and engineering community, we will write, perform and operate a set of Laboratory experiments and computer simulations supporting Electrical Engineering (graduate and undergraduate) courses on Renewable Energy, as well as Senior Design projects.

A happy conclusion to the SALT image quality saga

NASA Astrophysics Data System (ADS)

Crause, Lisa A.; O'Donoghue, Darragh E.; O'Connor, James E.; Strumpfer, Francois; Strydom, Ockert J.; Sass, Craig; du Plessis, Charl A.; Wiid, Eben; Love, Jonathan; Brink, Janus D.; Wilkinson, Martin; Coetzee, Chris

2012-09-01

Images obtained with the Southern African Large Telescope (SALT) during its commissioning phase showed degradation due to a large focus gradient and a variety of other optical aberrations. An extensive forensic investigation eventually traced the problem to the mechanical interface between the telescope and the secondary optics that form the Spherical Aberration Corrector (SAC). The SAC was brought down from the telescope in 2009 April, the problematic interface was replaced and the four corrector mirrors were optically tested and re-aligned. The surface figures of the SAC mirrors were confirmed to be within specification and a full system test following the re-alignment process yielded a RMS wavefront error of just 0.15 waves. The SAC was re-installed on the tracker in 2010 August and aligned with respect to the payload and primary mirror. Subsequent on-sky tests produced alarming results which were due to spurious signals being sent to the tracker by the auto-collimator, the instrument responsible for controlling the attitude of the SAC with respect to the primary mirror. Once this minor issue was resolved, we obtained uniform 1.1 arcsecond star images over the full 10 arcminute field of view of the telescope.

An experimental demonstration of a new type of proton computed tomography using a novel silicon tracking detector.

PubMed

Taylor, J T; Poludniowski, G; Price, T; Waltham, C; Allport, P P; Casse, G L; Esposito, M; Evans, P M; Green, S; Manger, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Symons, J; Allinson, N M

2016-11-01

Radiography and tomography using proton beams promise benefit to image guidance and treatment planning for proton therapy. A novel proton tracking detector is described and experimental demonstrations at a therapy facility are reported. A new type of proton CT reconstructing relative "scattering power" rather than "stopping power" is also demonstrated. Notably, this new type of imaging does not require the measurement of the residual energies of the protons. A large area, silicon microstrip tracker with high spatial and temporal resolution has been developed by the Proton Radiotherapy Verification and Dosimetry Applications consortium and commissioned using beams of protons at iThemba LABS, Medical Radiation Department, South Africa. The tracker comprises twelve planes of silicon developed using technology from high energy physics with each plane having an active area of ∼10 × 10 cm segmented into 2048 microstrips. The tracker is organized into four separate units each containing three detectors at 60° to one another creating an x-u-v coordinate system. Pairs of tracking units are used to reconstruct vertices for protons entering and exiting a phantom containing tissue equivalent inserts. By measuring the position and direction of each proton before and after the phantom, the nonlinear path for each proton through an object can be reconstructed. Experimental results are reported for tracking the path of protons with initial energies of 125 and 191 MeV. A spherical phantom of 75 mm diameter was imaged by positioning it between the entrance and exit detectors of the tracker. Positions and directions of individual protons were used to create angular distributions and 2D fluence maps of the beam. These results were acquired for 36 equally spaced projections spanning 180°, allowing, for the first time, an experimental CT image based upon the relative scattering power of protons to be reconstructed. Successful tracking of protons through a thick target (phantom) has demonstrated that the tracker discussed in this paper can provide the precise directional information needed to perform proton radiography and tomography. When synchronized with a range telescope, this could enable the reconstruction of proton CT images of stopping power. Furthermore, by measuring the deflection of many protons through a phantom, it was demonstrated that it is possible to reconstruct a new kind of CT image (scattering power) based upon this tracking information alone.

Singlet fission/silicon solar cell exceeding 100% EQE (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pazos, Luis M.; Lee, Jumin; Kirch, Anton; Tabachnyk, Maxim; Friend, Richard H.; Ehrler, Bruno

2016-09-01

Current matching limits the commercialization of tandem solar cells due to their instability over spectral changes, leading to the need of using solar concentrators and trackers to keep the spectrum stable. We demonstrate that voltage-matched systems show far higher performance over spectral changes; caused by clouds, dust and other variations in atmospheric conditions. Singlet fission is a process in organic semiconductors which has shown very efficient, 200%, down-conversion yield and the generated excitations are long-lived, ideal for solar cells. As a result, the number of publications has grown exponentially in the past 5 years. Yet, so far no one has achieved to combine singlet fission with most low bandgap semiconductors, including crystalline silicon, the dominating solar cell material with a 90% share of the PV Market. Here we show that singlet fission can facilitate the fabrication of voltage-matched systems, opening a simple design route for the effective implementation of down-conversion in commercially available photovoltaic technologies, with no modification of the electronic circuitry of such. The implemention of singlet fission is achieved simply by decoupling the fabrication of the individual subcells. For this demonstration we used an ITO/PEDOT/P3HT/Pentacene/C60/Ag wide-bandgap subcell, and a commercial silicon solar cell as the low-bandgap component. We show that the combination of the two leads to the first tandem silicon solar cell which exceeds 100% external quantum efficiency.

A bill to require the Consumer Product Safety Commission to study and report on the impact on consumers of permitting an increase in the amount of ethanol blended with gasoline for use in gasoline-powered engines used in vehicles operated in interstate commerce, on public streets and roads, or offroad, appliances such as lawn mowers and other nonvehicular devices, and marine engines, and to require the National Highway Traffic Safety Administration to study and report on any safety or reliability impact of such an increase on motor vehicle engines and fuel systems.

THOMAS, 111th Congress

Sen. Hutchison, Kay Bailey [R-TX

2010-09-29

Senate - 09/29/2010 Read twice and referred to the Committee on Commerce, Science, and Transportation. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Towards zero-power ICT.

PubMed

Gammaitoni, Luca; Chiuchiú, D; Madami, M; Carlotti, G

2015-06-05

Is it possible to operate a computing device with zero energy expenditure? This question, once considered just an academic dilemma, has recently become strategic for the future of information and communication technology. In fact, in the last forty years the semiconductor industry has been driven by its ability to scale down the size of the complementary metal-oxide semiconductor-field-effect transistor, the building block of present computing devices, and to increase computing capability density up to a point where the power dissipated in heat during computation has become a serious limitation. To overcome such a limitation, since 2004 the Nanoelectronics Research Initiative has launched a grand challenge to address the fundamental limits of the physics of switches. In Europe, the European Commission has recently funded a set of projects with the aim of minimizing the energy consumption of computing. In this article we briefly review state-of-the-art zero-power computing, with special attention paid to the aspects of energy dissipation at the micro- and nanoscales.

Towards zero-power ICT

NASA Astrophysics Data System (ADS)

Gammaitoni, Luca; Chiuchiú, D.; Madami, M.; Carlotti, G.

2015-06-01

Is it possible to operate a computing device with zero energy expenditure? This question, once considered just an academic dilemma, has recently become strategic for the future of information and communication technology. In fact, in the last forty years the semiconductor industry has been driven by its ability to scale down the size of the complementary metal-oxide semiconductor-field-effect transistor, the building block of present computing devices, and to increase computing capability density up to a point where the power dissipated in heat during computation has become a serious limitation. To overcome such a limitation, since 2004 the Nanoelectronics Research Initiative has launched a grand challenge to address the fundamental limits of the physics of switches. In Europe, the European Commission has recently funded a set of projects with the aim of minimizing the energy consumption of computing. In this article we briefly review state-of-the-art zero-power computing, with special attention paid to the aspects of energy dissipation at the micro- and nanoscales.

Virtual commissioning of automated micro-optical assembly

NASA Astrophysics Data System (ADS)

Schlette, Christian; Losch, Daniel; Haag, Sebastian; Zontar, Daniel; Roßmann, Jürgen; Brecher, Christian

2015-02-01

In this contribution, we present a novel approach to enable virtual commissioning for process developers in micro-optical assembly. Our approach aims at supporting micro-optics experts to effectively develop assisted or fully automated assembly solutions without detailed prior experience in programming while at the same time enabling them to easily implement their own libraries of expert schemes and algorithms for handling optical components. Virtual commissioning is enabled by a 3D simulation and visualization system in which the functionalities and properties of automated systems are modeled, simulated and controlled based on multi-agent systems. For process development, our approach supports event-, state- and time-based visual programming techniques for the agents and allows for their kinematic motion simulation in combination with looped-in simulation results for the optical components. First results have been achieved for simply switching the agents to command the real hardware setup after successful process implementation and validation in the virtual environment. We evaluated and adapted our system to meet the requirements set by industrial partners-- laser manufacturers as well as hardware suppliers of assembly platforms. The concept is applied to the automated assembly of optical components for optically pumped semiconductor lasers and positioning of optical components for beam-shaping

Development of semiconductor tracking: The future linear collider case

NASA Astrophysics Data System (ADS)

Savoy-Navarro, Aurore

2011-04-01

An active R&D on silicon tracking for the linear collider, SiLC, is pursued since several years to develop the new generation of large area silicon trackers for the future linear collider(s). The R&D objectives on new sensors, new front end processing of the signal, and the related mechanical and integration challenges for building such large detectors within the proposed detector concepts are described. Synergies and differences with the LHC construction and upgrades are explained. The differences between the linear collider projects, namely the international linear collider, ILC, and the compact linear collider, CLIC, are discussed as well. Two final objectives are presented for the construction of this important sub-detector for the future linear collider experiments: a relatively short term design based on micro-strips combined or not with a gaseous central tracker and a longer term design based on an all-pixel tracker.The R&D objectives on sensors include single sided micro-strips as baseline for the shorter term with the strips from large wafers (at least 6 in), 200 μm thick, 50 μm pitch and the edgeless and alignment friendly options. This work is conducted by SiLC in collaboration with three technical research centers in Italy, Finland, and Spain and HPK. SiLC is studied as well, using advanced Si sensor technologies for higher granularity trackers especially short strips and pixels all based on 3D technology. New Deep Sub-Micron CMOS mix mode (analog and digital) FE and readout electronics are developed to fully process the detector signals currently adapted to the ILC cycle. It is a high-level processing and a fully programmable ASIC; highly fault tolerant. In its latest version, handling 128 channels will equip these next coming years larger size silicon tracking prototypes at test beams. Connection of the FEE chip on the silicon detector especially in the strip case is a major issue. Very preliminary results with inline pitch adapter based on wiring were just achieved. Bump-bonding or 3D vertical interconnect is the other SiLC R&D objective. The goal is to simplify the overall architecture and decrease the material budget of these devices. Three tracking concepts are briefly discussed, two of which are part of the ILC Letter of Intent of the ILD and SiD detector concepts. These last years, SiLC successfully performed beam tests to experience and test these R&D lines.

System and method for calibrating inter-star-tracker misalignments in a stellar inertial attitude determination system

NASA Technical Reports Server (NTRS)

Li, Rongsheng (Inventor); Wu, Yeong-Wei Andy (Inventor); Hein, Douglas H. (Inventor)

2004-01-01

A method and apparatus for determining star tracker misalignments is disclosed. The method comprises the steps of defining a defining a reference frame for the star tracker assembly according to a boresight of the primary star tracker and a boresight of a second star tracker wherein the boresight of the primary star tracker and a plane spanned by the boresight of the primary star tracker and the boresight of the second star tracker at least partially define a datum for the reference frame for the star tracker assembly; and determining the misalignment of the at least one star tracker as a rotation of the defined reference frame.

Chapter 6: CPV Tracking and Trackers

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

Luque-Heredia, Ignacio; Magalhaes, Pedro; Muller, Matthew

2016-04-15

This chapter explains the functional requirements of a concentrator photovoltaic (CPV) sun tracker. It derives the design specifications of a CPV tracker. The chapter presents taxonomy of trackers describing the most common tracking architectures, based on the number of axes, their relative position, and the foundation and placing of tracking drives. It deals with the structural issues related to tracker design, mainly related to structural flexure and its impact on the system's acceptance angle. The chapter analyzes the auto-calibrated sun tracking control, by describing the state of the art and its development background. It explores the sun tracking accuracy measurementmore » with a practical example. The chapter discusses tracker manufacturing and tracker field works. It reviews survey of different types of tracker designs obtained from different manufacturers. Finally, the chapter deals with IEC62817, the technical standard developed for CPV sun trackers.« less

LysoTracker and MitoTracker Red are transport substrates of P-glycoprotein: implications for anticancer drug design evading multidrug resistance.

PubMed

Zhitomirsky, Benny; Farber, Hodaya; Assaraf, Yehuda G

2018-04-01

LysoTracker and MitoTracker Red are fluorescent probes widely used for viable cell staining of lysosomes and mitochondria, respectively. They are utilized to study organelle localization and their resident proteins, assess organelle functionality and quantification of organelle numbers. The ATP-driven efflux transporter P-glycoprotein (P-gp) is expressed in normal and malignant tissues and extrudes structurally distinct endogenous and exogenous cytotoxic compounds. Thus, once aromatic hydrophobic compounds such as the above-mentioned fluorescent probes are recognized as transport substrates, efflux pumps including P-gp may abolish their ability to reach their cellular target organelles. Herein, we show that LysoTracker and MitoTracker Red are expelled from P-gp-overexpressing cancer cells, thus hindering their ability to fluorescently mark target organelles. We further demonstrate that tariquidar, a potent P-gp transport inhibitor, restores LysoTracker and MitoTracker Red cell entry. We conclude that LysoTracker and MitoTracker Red are P-gp transport substrates, and therefore, P-gp expression must be taken into consideration prior to cellular applications using these probes. Importantly, as MitoTracker was a superior P-gp substrate than LysoTracker Red, we discuss the implications for the future design of chemotherapeutics evading cancer multidrug resistance. Furthermore, restoration of MitoTracker Red fluorescence in P-gp-overexpressing cells may facilitate the identification of potent P-gp transport inhibitors (i.e. chemosensitizers). © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Can a Free Wearable Activity Tracker Change Behavior? The Impact of Trackers on Adults in a Physician-Led Wellness Group.

PubMed

Gualtieri, Lisa; Rosenbluth, Sandra; Phillips, Jeffrey

2016-11-30

Wearable activity trackers (trackers) are increasingly popular devices used to track step count and other health indicators. Trackers have the potential to benefit those in need of increased physical activity, such as adults who are older and face significant health challenges. These populations are least likely to purchase trackers and most likely to face challenges in using them, yet may derive educational, motivational, and health benefits from their use once these barriers are removed. The aim of this pilot research is to investigate the use of trackers by adults with chronic medical conditions who have never used trackers previously. Specifically, we aim to determine (1) if participants would accept and use trackers to increase their physical activity; (2) if there were barriers to use besides cost and training; (3) if trackers would educate participants on their baseline and ongoing activity levels and support behavior change; and (4) if clinical outcomes would show improvements in participants' health. This study was conducted with patients (N=10) in a 12-week physician-led wellness group offered by Family Doctors, LLC. Patients were given trackers in the second week of The Wellness Group and were interviewed 2 to 4 weeks after it ended. The study investigators analyzed the interview notes to extract themes about the participants' attitudes and behavior changes and collected and analyzed participants' clinical data, including weight and low-density lipoprotein (LDL) cholesterol over the course of the study. Over the 12 to 14 weeks of tracker use, improvements were seen in clinical outcomes, attitudes towards the trackers, and physical activity behaviors. Participants lost an average of 0.5 lbs per week (SD 0.4), with a mean total weight loss of 5.97 lbs (P=.004). Other short-term clinical outcomes included a 9.2% decrease in LDL levels (P=.038). All participants reported an increase in well-being and confidence in their ability to lead more active lives. We identified the following 6 major attitudinal themes from our qualitative analysis of the interview notes: (1) barriers to tracker purchase included cost, perceived value, and choice confusion; (2) attitudes towards the trackers shifted for many, from half of the participants expressing excitement and hope and half expressing hesitation or trepidation, to all participants feeling positive towards their tracker at the time of the interviews; (3) trackers served as educational tools for baseline activity levels; (4) trackers provided concrete feedback on physical activity, which motivated behavior change; (5) tracker use reinforced wellness group activities and goals; and (6) although commitment to tracker use did not waver, external circumstances influenced some participants' ongoing use. Our findings suggest that adding trackers to wellness groups comprising primarily older adults with chronic medical conditions can support education and behavior change to be more physically active. The trackers increased participant self-efficacy by providing a tangible, visible reminder of a commitment to increasing activity and immediate feedback on step count and progress towards a daily step goal. While acceptance was high and attitudes ultimately positive, training and support are needed and short-term drop-off in participant use is to be expected. Future research will further consider the potential of trackers in older adults with chronic medical conditions who are unlikely to purchase them, and studies will use larger samples, continue over a longer period of time, and evaluate outcomes independent of a wellness group. ©Lisa Gualtieri, Sandra Rosenbluth, Jeffrey Phillips. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 30.11.2016.

DYNSYL: a general-purpose dynamic simulator for chemical processes

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

Patterson, G.K.; Rozsa, R.B.

1978-09-05

Lawrence Livermore Laboratory is conducting a safeguards program for the Nuclear Regulatory Commission. The goal of the Material Control Project of this program is to evaluate material control and accounting (MCA) methods in plants that handle special nuclear material (SNM). To this end we designed and implemented the dynamic chemical plant simulation program DYNSYL. This program can be used to generate process data or to provide estimates of process performance; it simulates both steady-state and dynamic behavior. The MCA methods that may have to be evaluated range from sophisticated on-line material trackers such as Kalman filter estimators, to relatively simplemore » material balance procedures. This report describes the overall structure of DYNSYL and includes some example problems. The code is still in the experimental stage and revision is continuing.« less

Improved color coordinates of green monochromatic pc-LED capped with a band-pass filter.

PubMed

Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Young Rag

2013-02-25

This study introduces a "greener" green monochromatic phosphor-converted light-emitting diode (pc-LED) using a band-pass filter (BPF) combined with a long-pass dichroic filter (LPDF) and a short-pass dichroic filter (SPDF) to improve the color quality of our previously developed LPDF-capped green pc-LED. This can also address the drawbacks of III-V semiconductor-type green LEDs, which show a low luminous efficacy and a poor current dependence of the efficacy and color coordinates compared to blue semiconductor-type LEDs. The optical properties of green monochromatic pc-LEDs using a BPF are compared with those of LPDF-capped green pc-LEDs, which have a broad band spectrum, and III-V semiconductor-type green LEDs by changing the transmittance wavelength range of the BPF and the peak wavelength of the green phosphors. BPF-capped green monochromatic pc-LEDs provide a high luminous efficacy (134 lm/W at 60 mA), and "greener" 1931 Commission Internationale d'Eclairage (CIE; CIEx, CIEy) color coordinates (0.24, 0.66) owing to the narrowed emission spectrum. We also propose a two-dimensional (2D) polystyrene (PS) microbead (2-μm diameter) monolayer as a scattering layer to overcome the poor angular dependence of the color coordinates of the transmitted light through a nano-multilayered dichroic filter such as an LPDF or BPF. The 2D PS scattering layer improves the angular dependence of the green color emitted from a BPF-capped green pc-LED with only 3% loss of luminous efficacy.

Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

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

Riley, Daniel; Hansen, Clifford W.

Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam ontomore » the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.« less

Testing FlowTracker2 Performance and Wading Rod Flow Disturbance in Laboratory Tow Tanks

NASA Astrophysics Data System (ADS)

Fan, X.; Wagenaar, D.

2016-12-01

The FlowTracker2 was released in February 2016 by SonTek (Xylem) to be a more feature-rich and technologically advanced replacement to the Original FlowTracker ADV. These instruments are Acoustic Doppler Velocimeters (ADVs) used for taking high-precision wading discharge and velocity measurements. The accuracy of the FlowTracker2 probe was tested in tow tanks at three different facilities: the USGS Hydrologic Instrumentation Facility (HIF), the Swiss Federal Institute for Metrology (METAS), and at the SonTek Research and Development facility. Multiple mounting configurations were examined, including mounting the ADV probe directly to the tow carts, and incorporating the two most-used wading rods for the FlowTracker (round and hex). Tow speeds ranged from 5cm/s to 1.5m/s, and different tow tank seeding schemes and wait times were examined. In addition, the performance of the FlowTracker2 probe in low Signal-to-Noise Ratio (SNR) environments was compared to the Original FlowTracker ADV. Results confirmed that the FlowTracker2 probe itself performed well within the 1%+0.25cm/s accuracy specification advertised. Tows using the wading rods created a reduced measured velocity by 1.3% of the expected velocity due to flow disturbance, a result similar to the Original FlowTracker ADV despite the change in the FlowTracker2 probe design. Finally, due to improvements in its electronics, the FlowTracker2's performance in low SNR tests exceeded that of the Original FlowTracker ADV, showing less standard error in these conditions compared to its predecessor.

Operational Experience with Autonomous Star Trackers on ESA Interplanetary Spacecraft

NASA Technical Reports Server (NTRS)

Lauer, Mathias; Jauregui, Libe; Kielbassa, Sabine

2007-01-01

Mars Express (MEX), Rosetta and Venus Express (VEX) are ESA interplanetary spacecrafts (S/C) launched in June 2003, March 2004 and November 2005, respectively. Mars Express was injected into Mars orbit end of 2003 with routine operations starting in spring 2004. Rosetta is since launch on its way to rendezvous comet Churyumov-Gerasimenko in 2014. It has completed several test and commissioning activities and is performing several planetary swingbys (Earth in spring 2005, Mars in spring 2007, Earth in autumn 2007 and again two years later). Venus Express has also started routine operations since the completion of the Venus orbit insertion maneuver sequence beginning of May 2006. All three S/C are three axes stabilized with a similar attitude and orbit control system (AOCS). The attitude is estimated on board using star and rate sensors and controlled using four reaction wheels. A bipropellant reaction control system with 10N thrusters serves for wheel off loadings and attitude control in safe mode. Mars Express and Venus Express have an additional 400N engine for the planetary orbit insertion. Nominal Earth communication is accomplished through a high gain antenna. All three S/C are equipped with a redundant set of autonomous star trackers (STR) which are based on almost the same hardware. The STR software is especially adapted for the respective mission. This paper addresses several topics related to the experience gained with the STR operations on board the three S/C so far.

Which cue to ‘want’? Opioid stimulation of central amygdala makes goal-trackers show stronger goal-tracking, just as sign-trackers show stronger sign-tracking

PubMed Central

DiFeliceantonio, Alexandra G.; Berridge, Kent C.

2012-01-01

Pavlovian cues that have been paired with reward can gain incentive salience. Drug addicts find drug cues motivationally attractive and binge eaters are attracted by food cues. But the level of incentive salience elicited by a cue re-encounter still varies across time and brain states. In an animal model, cues become attractive and ‘wanted’ in an ‘autoshaping’ paradigm, where different targets of incentive salience emerge for different individuals. Some individuals (sign-trackers) find a predictive discrete cue attractive while others find a reward contiguous and goal cue more attractive (location where reward arrives: goal-trackers). Here we assessed whether central amygdala mu opioid receptor stimulation enhances the phasic incentive salience of the goal-cue for goal-trackers during moments of predictive cue presence (expressed in both approach and consummatory behaviors to goal cue), just as it enhances the attractiveness of the predictive cue target for sign-trackers. Using detailed video analysis we measured the approaches, nibbles, sniffs, and bites directed at their preferred target for both sign-trackers and goal-trackers. We report that DAMGO microinjections in central amygdala made goal-trackers, like sign-trackers, show phasic increases in appetitive nibbles and sniffs directed at the goal-cue expressed selectively whenever the predictive cue was present. This indicates enhancement of incentive salience attributed by both goal trackers and sign-trackers, but attributed in different directions: each to their own target cue. For both phenotypes, amygdala opioid stimulation makes the individual’s prepotent cue into a stronger motivational magnet at phasic moments triggered by a CS that predicts the reward UCS. PMID:22391118

Autonomous star tracker based on active pixel sensors (APS)

NASA Astrophysics Data System (ADS)

Schmidt, U.

2017-11-01

Star trackers are opto-electronic sensors used onboard of satellites for the autonomous inertial attitude determination. During the last years, star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The Jena-Optronik GmbH is active in the field of opto-electronic sensors like star trackers since the early 80-ties. Today, with the product family ASTRO5, ASTRO10 and ASTRO15, all marked segments like earth observation, scientific applications and geo-telecom are supplied to European and Overseas customers. A new generation of star trackers can be designed based on the APS detector technical features. The measurement performance of the current CCD based star trackers can be maintained, the star tracker functionality, reliability and robustness can be increased while the unit costs are saved.

Interest and preferences for using advanced physical activity tracking devices: results of a national cross-sectional survey

PubMed Central

Alley, Stephanie; Schoeppe, Stephanie; Guertler, Diana; Jennings, Cally; Vandelanotte, Corneel

2016-01-01

Objectives Pedometers are an effective self-monitoring tool to increase users' physical activity. However, a range of advanced trackers that measure physical activity 24 hours per day have emerged (eg, Fitbit). The current study aims to determine people's current use, interest and preferences for advanced trackers. Design and participants A cross-sectional national telephone survey was conducted in Australia with 1349 respondents. Outcome measures Regression analyses were used to determine whether tracker interest and use, and use of advanced trackers over pedometers is a function of demographics. Preferences for tracker features and reasons for not wanting to wear a tracker are also presented. Results Over one-third of participants (35%) had used a tracker, and 16% are interested in using one. Multinomial regression (n=1257) revealed that the use of trackers was lower in males (OR=0.48, 95% CI 0.36 to 0.65), non-working participants (OR=0.43, 95% CI 0.30 to 0.61), participants with lower education (OR=0.52, 95% CI 0.38 to 0.72) and inactive participants (OR=0.52, 95% CI 0.39 to 0.70). Interest in using a tracker was higher in younger participants (OR=1.73, 95% CI 1.15 to 2.58). The most frequently used tracker was a pedometer (59%). Logistic regression (n=445) revealed that use of advanced trackers compared with pedometers was higher in males (OR=1.67, 95% CI 1.01 to 2.79) and younger participants (OR=2.96, 95% CI 1.71 to 5.13), and lower in inactive participants (OR=0.35, 95% CI 0.19 to 0.63). Over half of current or interested tracker users (53%) prefer to wear it on their wrist, 31% considered counting steps the most important function and 30% regarded accuracy as the most important characteristic. The main reasons for not wanting to use a tracker were, ‘I don't think it would help me’ (39%), and ‘I don't want to increase my activity’ (47%). Conclusions Activity trackers are a promising tool to engage people in self-monitoring a physical activity. Trackers used in physical activity interventions should align with the preferences of target groups, and should be able to be worn on the wrist, measure steps and be accurate. PMID:27388359

Precision Pointing Control System (PPCS) star tracker test

NASA Technical Reports Server (NTRS)

1972-01-01

Tests performed on the TRW precision star tracker are described. The unit tested was a two-axis gimballed star tracker designed to provide star LOS data to an accuracy of 1 to 2 sec. The tracker features a unique bearing system and utilizes thermal and mechanical symmetry techniques to achieve high precision which can be demonstrated in a one g environment. The test program included a laboratory evaluation of tracker functional operation, sensitivity, repeatibility, and thermal stability.

Small star trackers for modern space vehicles

NASA Astrophysics Data System (ADS)

Kouzmin, Vladimir; Jushkov, Vladimir; Zaikin, Vladimir

2017-11-01

Based on experience of many years creation of spacecrafts' star trackers with diversified detectors (from the first star trackers of 60's to tens versions of star trackers in the following years), using technological achievements in the field of optics and electronics the NPP "Geofizika-Cosmos" has provided celestial orientation for all the space vehicles created in Russia and now has developed a series of new star trackers with CCD matrix and special processors, which are able to meet needs in celestial orientation of the modern spacecrafts for the nearest 10-15 years. In the given article the main characteristics and description of some star trackers' versions are presented. The star trackers have various levels of technical characteristics and use both combined (Russian and foreign) procurement parts, and only national (Russian) procurement parts for the main units.

Two-Photon-Absorption Scheme for Optical Beam Tracking

NASA Technical Reports Server (NTRS)

Ortiz, Gerardo G.; Farr, William H.

2011-01-01

A new optical beam tracking approach for free-space optical communication links using two-photon absorption (TPA) in a high-bandgap detector material was demonstrated. This tracking scheme is part of the canonical architecture described in the preceding article. TPA is used to track a long-wavelength transmit laser while direct absorption on the same sensor simultaneously tracks a shorter-wavelength beacon. The TPA responsivity was measured for silicon using a PIN photodiode at a laser beacon wavelength of 1,550 nm. As expected, the responsivity shows a linear dependence with incident power level. The responsivity slope is 4.5 x 10(exp -7) A/W2. Also, optical beam spots from the 1,550-nm laser beacon were characterized on commercial charge coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) imagers with as little as 13.7 microWatts of optical power (see figure). This new tracker technology offers an innovative solution to reduce system complexity, improve transmit/receive isolation, improve optical efficiency, improve signal-to-noise ratio (SNR), and reduce cost for free-space optical communications transceivers.

Improved charge injection device and a focal plane interface electronics board for stellar tracking

NASA Technical Reports Server (NTRS)

Michon, G. J.; Burke, H. K.

1984-01-01

An improved Charge Injection Device (CID) stellar tracking sensor and an operating sensor in a control/readout electronics board were developed. The sensor consists of a shift register scanned, 256x256 CID array organized for readout of 4x4 subarrays. The 4x4 subarrays can be positioned anywhere within the 256x256 array with a 2 pixel resolution. This allows continuous tracking of a number of stars simultaneously since nine pixels (3x3) centered on any star can always be read out. Organization and operation of this sensor and the improvements in design and semiconductor processing are described. A hermetic package incorporating an internal thermoelectric cooler assembled using low temperature solders was developed. The electronics board, which contains the sensor drivers, amplifiers, sample hold circuits, multiplexer, analog to digital converter, and the sensor temperature control circuits, is also described. Packaged sensors were evaluated for readout efficiency, spectral quantum efficiency, temporal noise, fixed pattern noise, and dark current. Eight sensors along with two tracker electronics boards were completed, evaluated, and delivered.

Dual mode scanner-tracker

NASA Astrophysics Data System (ADS)

Mongeon, R. J.

1984-11-01

The beam of a laser radar is moved over the field of view by means of a pair of scanner/trackers arranged in cascade along the laser beam. One of the scanner/trackers operates at high speed, with high resolution and a wide field and is located in the demagnified portion of the laser beam. The two scanner/trackers complement each other to achieve high speed, high resolution scanning as well as tracking of moving targets. A beam steering telescope for an airborne laser radar which incorporates the novel dual mode scanner/tracker is also shown. The other scanner/tracker operates at low speed with low resolution and a wide field and is located in the magnified portion of the laser beam.

Nulling at the Keck Interferometer

NASA Technical Reports Server (NTRS)

Colavita, M. Mark; Serabyn, Gene; Wizinowich, Peter L.; Akeson, Rachel L.

2006-01-01

The nulling mode of the Keck Interferometer is being commissioned at the Mauna Kea summit. The nuller combines the two Keck telescope apertures in a split-pupil mode to both cancel the on-axis starlight and to coherently detect the residual signal. The nuller, working at 10 um, is tightly integrated with the other interferometer subsystems including the fringe and angle trackers, the delay lines and laser metrology, and the real-time control system. Since first 10 um light in August 2004, the system integration is proceeding with increasing functionality and performance, leading to demonstration of a 100:1 on-sky null in 2005. That level of performance has now been extended to observations with longer coherent integration times. An overview of the overall system is presented, with emphasis on the observing sequence, phasing system, and differences with respect to the V2 system, along with a presentation of some recent engineering data.

STS-88 Day 11 Highlights

NASA Technical Reports Server (NTRS)

1998-01-01

On this eleventh day of the STS-88 mission, the flight crew, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, James H. Newman, Jerry L. Ross, and Sergei Krikalev are awakened with the song "Goodnight, Sweetheart, Goodnight". Pilot Rick Sturckow undocks Endeavour from the station and backs the shuttle away to a distance of 450 feet above the station before beginning a nose-forward fly-around. Later Cabana, Sturckow and Ross deploy the SAC-A satellite from Endeavour's payload bay. SAC-A is a small, self-contained, non-recoverable satellite built by the Argentinean National Commission of Space Activities. The cube-shaped, 590-pound satellite will test and characterize the performance of new equipment and technologies that may be used in future scientific or operational missions. The payload includes a differential global positioning system, a magnetometer, silicon solar cells, a charge-coupled device Earth camera and a whale tracker experiment.

A Novel Performance Evaluation Methodology for Single-Target Trackers.

PubMed

Kristan, Matej; Matas, Jiri; Leonardis, Ales; Vojir, Tomas; Pflugfelder, Roman; Fernandez, Gustavo; Nebehay, Georg; Porikli, Fatih; Cehovin, Luka

2016-11-01

This paper addresses the problem of single-target tracker performance evaluation. We consider the performance measures, the dataset and the evaluation system to be the most important components of tracker evaluation and propose requirements for each of them. The requirements are the basis of a new evaluation methodology that aims at a simple and easily interpretable tracker comparison. The ranking-based methodology addresses tracker equivalence in terms of statistical significance and practical differences. A fully-annotated dataset with per-frame annotations with several visual attributes is introduced. The diversity of its visual properties is maximized in a novel way by clustering a large number of videos according to their visual attributes. This makes it the most sophistically constructed and annotated dataset to date. A multi-platform evaluation system allowing easy integration of third-party trackers is presented as well. The proposed evaluation methodology was tested on the VOT2014 challenge on the new dataset and 38 trackers, making it the largest benchmark to date. Most of the tested trackers are indeed state-of-the-art since they outperform the standard baselines, resulting in a highly-challenging benchmark. An exhaustive analysis of the dataset from the perspective of tracking difficulty is carried out. To facilitate tracker comparison a new performance visualization technique is proposed.

Wellbeing in the Making: Peoples' Experiences with Wearable Activity Trackers.

PubMed

Karapanos, Evangelos; Gouveia, Rúben; Hassenzahl, Marc; Forlizzi, Jodi

Wearable activity trackers have become a viable business opportunity. Nevertheless, research has raised concerns over their potentially detrimental effects on wellbeing. For example, a recent study found that while counting steps with a pedometer increased steps taken throughout the day, at the same time it decreased the enjoyment people derived from walking. This poses a serious threat to the incorporation of healthy routines into everyday life. Most studies aim at proving the effectiveness of activity trackers. In contrast, a wellbeing-oriented perspective calls for a deeper understanding of how trackers create and mediate meaningful experiences in everyday life. We present a study of real life experiences with three wearable activity trackers: Fitbit , Jawbone Up and Nike  +  Fuelband . Using need fulfillment as a theoretical lens, we study recent, memorable experiences submitted by 133 users of activity trackers. We reveal a two-dimensional structure of users' experience driven by the needs of physical thriving or relatedness. Our qualitative findings further show a nuanced picture of the adoption of activity trackers and their impact on wellbeing. For instance, while reflection about own exercising practices lost its relevance over time, users continued to wear the tracker to document and collect their runs. More than just supporting behavioral change, we find trackers to provide multiple psychological benefits. For instance, they enhance feelings of autonomy as people gain more control about their exercising regime. Others experience relatedness, when family members purchase a tracker for relatives and join them in their efforts towards a better, healthier self. The study highlights that activity trackers can be more than "tools" to change behavior. Through incorporation in daily life, they offer new social experiences, new ways of boosting our self-esteem and getting closer to our ideal selves.

How Accurate Is Your Activity Tracker? A Comparative Study of Step Counts in Low-Intensity Physical Activities

PubMed Central

2017-01-01

Background As commercially available activity trackers are being utilized in clinical trials, the research community remains uncertain about reliability of the trackers, particularly in studies that involve walking aids and low-intensity activities. While these trackers have been tested for reliability during walking and running activities, there has been limited research on validating them during low-intensity activities and walking with assistive tools. Objective The aim of this study was to (1) determine the accuracy of 3 Fitbit devices (ie, Zip, One, and Flex) at different wearing positions (ie, pants pocket, chest, and wrist) during walking at 3 different speeds, 2.5, 5, and 8 km/h, performed by healthy adults on a treadmill; (2) determine the accuracy of the mentioned trackers worn at different sites during activities of daily living; and (3) examine whether intensity of physical activity (PA) impacts the choice of optimal wearing site of the tracker. Methods We recruited 15 healthy young adults to perform 6 PAs while wearing 3 Fitbit devices (ie, Zip, One, and Flex) on their chest, pants pocket, and wrist. The activities include walking at 2.5, 5, and 8 km/h, pushing a shopping cart, walking with aid of a walker, and eating while sitting. We compared the number of steps counted by each tracker with gold standard numbers. We performed multiple statistical analyses to compute descriptive statistics (ie, ANOVA test), intraclass correlation coefficient (ICC), mean absolute error rate, and correlation by comparing the tracker-recorded data with that of the gold standard. Results All the 3 trackers demonstrated good-to-excellent (ICC>0.75) correlation with the gold standard step counts during treadmill experiments. The correlation was poor (ICC<0.60), and the error rate was significantly higher in walker experiment compared to other activities. There was no significant difference between the trackers and the gold standard in the shopping cart experiment. The wrist worn tracker, Flex, counted several steps when eating (P<.01). The chest tracker was identified as the most promising site to capture steps in more intense activities, while the wrist was the optimal wearing site in less intense activities. Conclusions This feasibility study focused on 6 PAs and demonstrated that Fitbit trackers were most accurate when walking on a treadmill and least accurate during walking with a walking aid and for low-intensity activities. This may suggest excluding participants with assistive devices from studies that focus on PA interventions using commercially available trackers. This study also indicates that the wearing site of the tracker is an important factor impacting the accuracy performance. A larger scale study with a more diverse population, various activity tracker vendors, and a larger activity set are warranted to generalize our results. PMID:28801304

Precision Attitude Determination System (PADS) system design and analysis: Single-axis gimbal star tracker

NASA Technical Reports Server (NTRS)

1974-01-01

The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation analysis to evaluate performance potential. Star availability and covariance analysis digital computer programs are included.

Monolithic Inorganic ZnO/GaN Semiconductors Heterojunction White Light-Emitting Diodes.

PubMed

Jeong, Seonghoon; Oh, Seung Kyu; Ryou, Jae-Hyun; Ahn, Kwang-Soon; Song, Keun Man; Kim, Hyunsoo

2018-01-31

Monolithic light-emitting diodes (LEDs) that can generate white color at the one-chip level without the wavelength conversion through packaged phosphors or chip integration for photon recycling are of particular importance to produce compact, cost-competitive, and smart lighting sources. In this study, monolithic white LEDs were developed based on ZnO/GaN semiconductor heterojunctions. The electroluminescence (EL) wavelength of the ZnO/GaN heterojunction could be tuned by a post-thermal annealing process, causing the generation of an interfacial Ga 2 O 3 layer. Ultraviolet, violet-bluish, and greenish-yellow broad bands were observed from n-ZnO/p-GaN without an interfacial layer, whereas a strong greenish-yellow band emission was the only one observed from that with an interfacial layer. By controlled integration of ZnO/GaN heterojunctions with different postannealing conditions, monolithic white LED was demonstrated with color coordinates in the range (0.3534, 0.3710)-(0.4197, 0.4080) and color temperatures of 4778-3349 K in the Commission Internationale de l'Eclairage 1931 chromaticity diagram. Furthermore, the monolithic white LED produced approximately 2.1 times higher optical output power than a conventional ZnO/GaN heterojunction due to the carrier confinement effect at the Ga 2 O 3 /n-ZnO interface.

Assessment of radiation exposure in dental cone-beam computerized tomography with the use of metal-oxide semiconductor field-effect transistor (MOSFET) dosimeters and Monte Carlo simulations.

PubMed

Koivisto, J; Kiljunen, T; Tapiovaara, M; Wolff, J; Kortesniemi, M

2012-09-01

The aims of this study were to assess the organ and effective dose (International Commission on Radiological Protection (ICRP) 103) resulting from dental cone-beam computerized tomography (CBCT) imaging using a novel metal-oxide semiconductor field-effect transistor (MOSFET) dosimeter device, and to assess the reliability of the MOSFET measurements by comparing the results with Monte Carlo PCXMC simulations. Organ dose measurements were performed using 20 MOSFET dosimeters that were embedded in the 8 most radiosensitive organs in the maxillofacial and neck area. The dose-area product (DAP) values attained from CBCT scans were used for PCXMC simulations. The acquired MOSFET doses were then compared with the Monte Carlo simulations. The effective dose measurements using MOSFET dosimeters yielded, using 0.5-cm steps, a value of 153 μSv and the PCXMC simulations resulted in a value of 136 μSv. The MOSFET dosimeters placed in a head phantom gave results similar to Monte Carlo simulations. Minor vertical changes in the positioning of the phantom had a substantial affect on the overall effective dose. Therefore, the MOSFET dosimeters constitute a feasible method for dose assessment of CBCT units in the maxillofacial region. Copyright © 2012 Elsevier Inc. All rights reserved.

Balance-Equation Approach to Nonuniform Electron Transport in Nonparabolic Semiconductors

NASA Astrophysics Data System (ADS)

Cao, Juncheng; Lei, Xiaolin

1998-10-01

On the basis of the Lei-Ting balance-equation transport theory recently developed for nonparabolic energy band, we propose a hydrodynamic approach to the spatially inhomogeneous electron transport in semiconductor devices. In the present approach, the momentum and energy collision terms are expressed by two nonlinear functions, the frictional acceleration and energy-loss rate, which give a detailed scattering-process-level description of nonstationary and nonlocal charge transport in the system. This approach allows one to calculate selfconsistently the transport parameters within the model itself based on the primary material data (band structure, deformation potential constant, etc.), thus it minimizes the uncertainty associated with the use of some empirical relations for transport coefficients. As a demonstration of the approach, we have carried out a numerical calculation for a submicrometer Si n^+nn^+ diode by assuming an isotropic Kane-type energy band. The results for electron velocity and energy, obtained at much less computing cost than the Monte-Carlo (MC) method, are in good agreement with MC prediction. The influence of heat-flow term on electron transport behaviour, especially on velocity overshoot, is also investigated. The project supported by National Natural Science Foundation of China, National and Shanghai Municipal Commission of Science and Technology, and the Shanghai Foundation for Research and Development of Applied Materials

A novel adaptive sun tracker for spacecraft solar panel based on hybrid unsymmetric composite laminates

NASA Astrophysics Data System (ADS)

Wu, Zhangming; Li, Hao

2017-11-01

This paper proposes a novel adaptive sun tracker which is constructed by hybrid unsymmetric composite laminates. The adaptive sun tracker could be applied on spacecraft solar panels to increase their energy efficiency through decreasing the inclined angle between the sunlight and the solar panel normal. The sun tracker possesses a large rotation freedom and its rotation angle depends on the laminate temperature, which is affected by the light condition in the orbit. Both analytical model and finite element model (FEM) are developed for the sun tracker to predict its rotation angle in different light conditions. In this work, the light condition of the geosynchronous orbit on winter solstice is considered in the numerical prediction of the temperatures of the hybrid laminates. The final inclined angle between the sunlight and the solar panel normal during a solar day is computed using the finite element model. Parametric study of the adaptive sun tracker is conducted to improve its capacity and effectiveness of sun tracking. The improved adaptive sun tracker is lightweight and has a state-of-the-art design. In addition, the adaptive sun tracker does not consume any power of the solar panel, since it has no electrical driving devices. The proposed adaptive sun tracker provides a potential alternative to replace the traditional sophisticated electrical driving mechanisms for spacecraft solar panels.

Validation of an Electronic System for Recording Medical Student Patient Encounters

PubMed Central

Nkoy, Flory L.; Petersen, Sarah; Matheny Antommaria, Armand H.; Maloney, Christopher G.

2008-01-01

The Liaison Committee for Medical Education requires monitoring of the students’ clinical experiences. Student logs, typically used for this purpose, have a number of limitations. We used an electronic system called Patient Tracker to passively generate student encounter data. The data contained in Patient Tracker was compared to the information reported on student logs and data abstracted from the patients’ charts. Patient Tracker identified 30% more encounters than the student logs. Compared to the student logs, Patient Tracker contained a higher average number of diagnoses per encounter (2.28 vs. 1.03, p<0.01). The diagnostic data contained in Patient Tracker was also more accurate under 4 different definitions of accuracy. Only 1.3% (9/677) of diagnoses in Patient Tracker vs. 16.9% (102/601) diagnoses in the logs could not be validated in patients’ charts (p<0.01). Patient Tracker is a more effective and accurate tool for documenting student clinical encounters than the conventional student logs. PMID:18999155

How Accurate Is Your Activity Tracker? A Comparative Study of Step Counts in Low-Intensity Physical Activities.

PubMed

Alinia, Parastoo; Cain, Chris; Fallahzadeh, Ramin; Shahrokni, Armin; Cook, Diane; Ghasemzadeh, Hassan

2017-08-11

As commercially available activity trackers are being utilized in clinical trials, the research community remains uncertain about reliability of the trackers, particularly in studies that involve walking aids and low-intensity activities. While these trackers have been tested for reliability during walking and running activities, there has been limited research on validating them during low-intensity activities and walking with assistive tools. The aim of this study was to (1) determine the accuracy of 3 Fitbit devices (ie, Zip, One, and Flex) at different wearing positions (ie, pants pocket, chest, and wrist) during walking at 3 different speeds, 2.5, 5, and 8 km/h, performed by healthy adults on a treadmill; (2) determine the accuracy of the mentioned trackers worn at different sites during activities of daily living; and (3) examine whether intensity of physical activity (PA) impacts the choice of optimal wearing site of the tracker. We recruited 15 healthy young adults to perform 6 PAs while wearing 3 Fitbit devices (ie, Zip, One, and Flex) on their chest, pants pocket, and wrist. The activities include walking at 2.5, 5, and 8 km/h, pushing a shopping cart, walking with aid of a walker, and eating while sitting. We compared the number of steps counted by each tracker with gold standard numbers. We performed multiple statistical analyses to compute descriptive statistics (ie, ANOVA test), intraclass correlation coefficient (ICC), mean absolute error rate, and correlation by comparing the tracker-recorded data with that of the gold standard. All the 3 trackers demonstrated good-to-excellent (ICC>0.75) correlation with the gold standard step counts during treadmill experiments. The correlation was poor (ICC<0.60), and the error rate was significantly higher in walker experiment compared to other activities. There was no significant difference between the trackers and the gold standard in the shopping cart experiment. The wrist worn tracker, Flex, counted several steps when eating (P<.01). The chest tracker was identified as the most promising site to capture steps in more intense activities, while the wrist was the optimal wearing site in less intense activities. This feasibility study focused on 6 PAs and demonstrated that Fitbit trackers were most accurate when walking on a treadmill and least accurate during walking with a walking aid and for low-intensity activities. This may suggest excluding participants with assistive devices from studies that focus on PA interventions using commercially available trackers. This study also indicates that the wearing site of the tracker is an important factor impacting the accuracy performance. A larger scale study with a more diverse population, various activity tracker vendors, and a larger activity set are warranted to generalize our results. ©Parastoo Alinia, Chris Cain, Ramin Fallahzadeh, Armin Shahrokni, Diane Cook, Hassan Ghasemzadeh. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 11.08.2017.

An analysis of automatic human detection and tracking

NASA Astrophysics Data System (ADS)

Demuth, Philipe R.; Cosmo, Daniel L.; Ciarelli, Patrick M.

2015-12-01

This paper presents an automatic method to detect and follow people on video streams. This method uses two techniques to determine the initial position of the person at the beginning of the video file: one based on optical flow and the other one based on Histogram of Oriented Gradients (HOG). After defining the initial bounding box, tracking is done using four different trackers: Median Flow tracker, TLD tracker, Mean Shift tracker and a modified version of the Mean Shift tracker using HSV color space. The results of the methods presented in this paper are then compared at the end of the paper.

A multi-hypothesis tracker for clicking whales.

PubMed

Baggenstoss, Paul M

2015-05-01

This paper describes a tracker specially designed to track clicking beaked whales using widely spaced bottom-mounted hydrophones, although it can be adapted to different species and sensors. The input to the tracker is a sequence of static localization solutions obtained using time difference of arrival information at widely spaced hydrophones. To effectively handle input localizations with high ambiguity, the tracker is based on multi-hypothesis tracker concepts, so it considers all potential association hypotheses and keeps a large number of potential tracks in memory. The method is demonstrated on actual data and shown to successfully track multiple beaked whales at depth.

Correlation tracking study for meter-class solar telescope on space shuttle. [solar granulation

NASA Technical Reports Server (NTRS)

Smithson, R. C.; Tarbell, T. D.

1977-01-01

The theory and expected performance level of correlation trackers used to control the pointing of a solar telescope in space using white light granulation as a target were studied. Three specific trackers were modeled and their performance levels predicted for telescopes of various apertures. The performance of the computer model trackers on computer enhanced granulation photographs was evaluated. Parametric equations for predicting tracker performance are presented.

Low-Frequency Error Extraction and Compensation for Attitude Measurements from STECE Star Tracker.

PubMed

Lai, Yuwang; Gu, Defeng; Liu, Junhong; Li, Wenping; Yi, Dongyun

2016-10-12

The low frequency errors (LFE) of star trackers are the most penalizing errors for high-accuracy satellite attitude determination. Two test star trackers- have been mounted on the Space Technology Experiment and Climate Exploration (STECE) satellite, a small satellite mission developed by China. To extract and compensate the LFE of the attitude measurements for the two test star trackers, a new approach, called Fourier analysis, combined with the Vondrak filter method (FAVF) is proposed in this paper. Firstly, the LFE of the two test star trackers' attitude measurements are analyzed and extracted by the FAVF method. The remarkable orbital reproducibility features are found in both of the two test star trackers' attitude measurements. Then, by using the reproducibility feature of the LFE, the two star trackers' LFE patterns are estimated effectively. Finally, based on the actual LFE pattern results, this paper presents a new LFE compensation strategy. The validity and effectiveness of the proposed LFE compensation algorithm is demonstrated by the significant improvement in the consistency between the two test star trackers. The root mean square (RMS) of the relative Euler angle residuals are reduced from [27.95'', 25.14'', 82.43''], 3σ to [16.12'', 15.89'', 53.27''], 3σ.

Technology transfer: Imaging tracker to robotic controller

NASA Technical Reports Server (NTRS)

Otaguro, M. S.; Kesler, L. O.; Land, Ken; Erwin, Harry; Rhoades, Don

1988-01-01

The transformation of an imaging tracker to a robotic controller is described. A multimode tracker was developed for fire and forget missile systems. The tracker locks on to target images within an acquisition window using multiple image tracking algorithms to provide guidance commands to missile control systems. This basic tracker technology is used with the addition of a ranging algorithm based on sizing a cooperative target to perform autonomous guidance and control of a platform for an Advanced Development Project on automation and robotics. A ranging tracker is required to provide the positioning necessary for robotic control. A simple functional demonstration of the feasibility of this approach was performed and described. More realistic demonstrations are under way at NASA-JSC. In particular, this modified tracker, or robotic controller, will be used to autonomously guide the Man Maneuvering Unit (MMU) to targets such as disabled astronauts or tools as part of the EVA Retriever efforts. It will also be used to control the orbiter's Remote Manipulator Systems (RMS) in autonomous approach and positioning demonstrations. These efforts will also be discussed.

Software and mathematical support of Kazakhstani star tracker

NASA Astrophysics Data System (ADS)

Akhmedov, D.; Yelubayev, S.; Ten, V.; Bopeyev, T.; Alipbayev, K.; Sukhenko, A.

2016-10-01

Currently the specialists of Kazakhstan have been developing the star tracker that is further planned to use on Kazakhstani satellites of various purposes. At the first stage it has been developed the experimental model of star tracker that has following characteristics: field of view 20°, update frequency 2 Hz, exclusion angle 40°, accuracy of attitude determination of optical axis/around optical axis 15/50 arcsec. Software and mathematical support are the most high technology parts of star tracker. The results of software and mathematical support development of experimental model of Kazakhstani star tracker are represented in this article. In particular, there are described the main mathematical models and algorithms that have been used as a basis for program units of preliminary image processing of starry sky, stars identification and star tracker attitude determination. The results of software and mathematical support testing with the help of program simulation complex using various configurations of defects including image sensor noises, point spread function modeling, optical system distortion up to 2% are presented. Analysis of testing results has shown that accuracy of attitude determination of star tracker is within the permissible range

Breadboard stellar tracker system test report, volume 1

NASA Technical Reports Server (NTRS)

Kollodge, J. C.; Hubbard, M. W.; Jain, S.; Schons, C. A.

1981-01-01

The performance of a star tracker equipped with a focal plane detector was evaluated. The CID board is an array of 256 x 256 pixels which are 20 x 20 micrometers in dimension. The tracker used for test was a breadboard tracker system developed by BASD. Unique acquisition and tracking algorithms are employed to enhance performance. A pattern recognition process is used to test for proper image spread function and to avoid false acquisition on noise. A very linear, high gain, interpixel transfer function is derived for interpolating star position. The lens used in the tracker has an EFL of 100 mm. The tracker has an FOV of 2.93 degrees resulting in a pixel angular subtense of 41.253 arc sec in each axis. The test procedure used for the program presented a star to the tracker in a circular pattern of positions; the pattern was formed by projecting a simulated star through a rotatable deviation wedge. Further tests determined readout noise, Noise Equivalent Displacement during track, and spatial noise during acquisition by taking related data and reducing it.

Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

PubMed Central

Sun, Ting; Xing, Fei; You, Zheng

2013-01-01

The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers. PMID:23567527

A protocol for evaluating video trackers under real-world conditions.

PubMed

Nawaz, Tahir; Cavallaro, Andrea

2013-04-01

The absence of a commonly adopted performance evaluation framework is hampering advances in the design of effective video trackers. In this paper, we present a single-score evaluation measure and a protocol to objectively compare trackers. The proposed measure evaluates tracking accuracy and failure, and combines them for both summative and formative performance assessment. The proposed protocol is composed of a set of trials that evaluate the robustness of trackers on a range of test scenarios representing several real-world conditions. The protocol is validated on a set of sequences with a diversity of targets (head, vehicle and person) and challenges (occlusions, background clutter, pose changes and scale changes) using six state-of-the-art trackers, highlighting their strengths and weaknesses on more than 187000 frames. The software implementing the protocol and the evaluation results are made available online and new results can be included, thus facilitating the comparison of trackers.

Determinants for Sustained Use of an Activity Tracker: Observational Study

PubMed Central

Moons, Jonas; Kerkhof, Peter; Wiekens, Carina; De Groot, Martijn

2017-01-01

Background A lack of physical activity is considered to cause 6% of deaths globally. Feedback from wearables such as activity trackers has the potential to encourage daily physical activity. To date, little research is available on the natural development of adherence to activity trackers or on potential factors that predict which users manage to keep using their activity tracker during the first year (and thereby increasing the chance of healthy behavior change) and which users discontinue using their trackers after a short time. Objective The aim of this study was to identify the determinants for sustained use in the first year after purchase. Specifically, we look at the relative importance of demographic and socioeconomic, psychological, health-related, goal-related, technological, user experience–related, and social predictors of feedback device use. Furthermore, this study tests the effect of these predictors on physical activity. Methods A total of 711 participants from four urban areas in France received an activity tracker (Fitbit Zip) and gave permission to use their logged data. Participants filled out three Web-based questionnaires: at start, after 98 days, and after 232 days to measure the aforementioned determinants. Furthermore, for each participant, we collected activity data tracked by their Fitbit tracker for 320 days. We determined the relative importance of all included predictors by using Random Forest, a machine learning analysis technique. Results The data showed a slow exponential decay in Fitbit use, with 73.9% (526/711) of participants still tracking after 100 days and 16.0% (114/711) of participants tracking after 320 days. On average, participants used the tracker for 129 days. Most important reasons to quit tracking were technical issues such as empty batteries and broken trackers or lost trackers (21.5% of all Q3 respondents, 130/601). Random Forest analysis of predictors revealed that the most influential determinants were age, user experience–related factors, mobile phone type, household type, perceived effect of the Fitbit tracker, and goal-related factors. We explore the role of those predictors that show meaningful differences in the number of days the tracker was worn. Conclusions This study offers an overview of the natural development of the use of an activity tracker, as well as the relative importance of a range of determinants from literature. Decay is exponential but slower than may be expected from existing literature. Many factors have a small contribution to sustained use. The most important determinants are technical condition, age, user experience, and goal-related factors. This finding suggests that activity tracking is potentially beneficial for a broad range of target groups, but more attention should be paid to technical and user experience–related aspects of activity trackers. PMID:29084709

Transport and release of colloidal 3-mercaptopropionic acid-coated CdSe–CdS/ZnS core-multishell quantum dots in human umbilical vein endothelial cells

PubMed Central

Fontana, Jacopo M; Yin, Huijuan; Chen, Yun; Florez, Ricardo; Brismar, Hjalmar; Fu, Ying

2017-01-01

Colloidal semiconductor quantum dots (QDs) have been extensively researched and developed for biomedical applications, including drug delivery and biosensing assays. Hence, it is pivotal to understand their behavior in terms of intracellular transport and toxicological effects. In this study, we focused on 3-mercaptopropionic acid-coated CdSe-CdS/ZnS core-multishell quantum dots (3MPA-QDs) converted from the as-grown octadecylamine-coated quantum dots (ODA-QDs) and their direct and dynamic interactions with human umbilical vein endothelial cells (HUVECs). Live cell imaging using confocal fluorescence microscopy showed that 3MPA-QDs first attached to and subsequently aggregated on HUVEC plasma membrane ~25 min after QD deposition. The aggregated QDs started being internalized at ~2 h and reached their highest internalization degree at ~24 h. They were released from HUVECs after ~48 h. During the 48 h period, the HUVECs responded normally to external stimulations, grew, proliferated and wound healed without any perceptible apoptosis. Furthermore, 1) 3MPA-QDs were internalized in newly formed LysoTracker-stained early endosomes; 2) adenosine 5′-triphosphate-induced [Ca2+]i modulation caused a transient decrease in the fluorescence of 3MPA-QDs that were attached to the plasma membrane but a transient increase in the internalized 3MPA-QDs; and 3) fluorescence signal modulations of co-stained LysoTracker and QDs induced by the lysosomotropic agent Gly-Phe-β-naphthylamide were spatially co-localized and temporally synchronized. Our findings suggest that 3MPA-QDs converted from ODA-QDs are a potential nontoxic fluorescent probe for future use in clinical applications. Moreover, the photophysical strategy and techniques reported in this work are easily applicable to study of direct interactions between other nanoparticles and live cells; contributing to awareness and implementation of the safe applications of nanoparticles. PMID:29270011

Transport and release of colloidal 3-mercaptopropionic acid-coated CdSe-CdS/ZnS core-multishell quantum dots in human umbilical vein endothelial cells.

PubMed

Fontana, Jacopo M; Yin, Huijuan; Chen, Yun; Florez, Ricardo; Brismar, Hjalmar; Fu, Ying

2017-01-01

Colloidal semiconductor quantum dots (QDs) have been extensively researched and developed for biomedical applications, including drug delivery and biosensing assays. Hence, it is pivotal to understand their behavior in terms of intracellular transport and toxicological effects. In this study, we focused on 3-mercaptopropionic acid-coated CdSe-CdS/ZnS core-multishell quantum dots (3MPA-QDs) converted from the as-grown octadecylamine-coated quantum dots (ODA-QDs) and their direct and dynamic interactions with human umbilical vein endothelial cells (HUVECs). Live cell imaging using confocal fluorescence microscopy showed that 3MPA-QDs first attached to and subsequently aggregated on HUVEC plasma membrane ~25 min after QD deposition. The aggregated QDs started being internalized at ~2 h and reached their highest internalization degree at ~24 h. They were released from HUVECs after ~48 h. During the 48 h period, the HUVECs responded normally to external stimulations, grew, proliferated and wound healed without any perceptible apoptosis. Furthermore, 1) 3MPA-QDs were internalized in newly formed LysoTracker-stained early endosomes; 2) adenosine 5'-triphosphate-induced [Ca 2+ ] i modulation caused a transient decrease in the fluorescence of 3MPA-QDs that were attached to the plasma membrane but a transient increase in the internalized 3MPA-QDs; and 3) fluorescence signal modulations of co-stained LysoTracker and QDs induced by the lysosomotropic agent Gly-Phe-β-naphthylamide were spatially co-localized and temporally synchronized. Our findings suggest that 3MPA-QDs converted from ODA-QDs are a potential nontoxic fluorescent probe for future use in clinical applications. Moreover, the photophysical strategy and techniques reported in this work are easily applicable to study of direct interactions between other nanoparticles and live cells; contributing to awareness and implementation of the safe applications of nanoparticles.

Optical Alignment of the Global Precipitation Measurement (GPM) Star Trackers

NASA Technical Reports Server (NTRS)

Hetherington, Samuel; Osgood, Dean; McMann, Joe; Roberts, Viki; Gill, James; Mclean, Kyle

2013-01-01

The optical alignment of the star trackers on the Global Precipitation Measurement (GPM) core spacecraft at NASA Goddard Space Flight Center (GSFC) was challenging due to the layout and structural design of the GPM Lower Bus Structure (LBS) in which the star trackers are mounted as well as the presence of the star tracker shades that blocked line-of-sight to the primary star tracker optical references. The initial solution was to negotiate minor changes in the original LBS design to allow for the installation of a removable item of ground support equipment (GSE) that could be installed whenever measurements of the star tracker optical references were needed. However, this GSE could only be used to measure secondary optical reference cube faces not used by the star tracker vendor to obtain the relationship information and matrix transformations necessary to determine star tracker alignment. Unfortunately, due to unexpectedly large orthogonality errors between the measured secondary adjacent cube faces and the lack of cube calibration data, we required a method that could be used to measure the same reference cube faces as originally measured by the vendor. We describe an alternative technique to theodolite auto-collimation for measurement of an optical reference mirror pointing direction when normal incidence measurements are not possible. This technique was used to successfully align the GPM star trackers and has been used on a number of other NASA flight projects. We also discuss alignment theory as well as a GSFC-developed theodolite data analysis package used to analyze angular metrology data.

Elliptically framed tip-tilt mirror optimized for stellar tracking

NASA Astrophysics Data System (ADS)

Clark, James H.; Penado, F. E.; Petak, Jeremy

2015-09-01

We compare a design innovation of an elliptically framed tip-tilt optical tracker with an existing circularly framed tracker for the Navy Precision Optical Interferometer. The tracker stabilizes a 12.5 cm stellar beam on a target hundreds of meters away and requires an increase in operational frequency. We reduced mass and size by integrating an elliptical mirror as one of the rotating components, which eliminated a rotating frame. We used the same materials as the existing tracker; however, light-weighted both the aluminum frame and Zerodur® mirror. We generated a computer-aided design model, converted it into a finite element model and performed modal analysis on two load cases. In load case 1, we tied down three points on the bottom surface of the tracker corresponding to the tie-down points of the comparison tracker. This reveals a first mode (lowest) frequency of 140 Hz, a factor of two over the baseline tracker's first mode frequency of 67 Hz. In load case 2, we constrained four additional points inboard of the corners of the tracker base, for a total of seven tie-downs, simulating a firmly bolted and secured mount. The first mode of vibration for this case is 211 Hz, an increase over load case 1 by a factor of 1.5 and more than three times the fundamental frequency of the existing tracker. We conclude that these geometrical changes with the additional tie-down bolts are a viable solution path forward to improve steering speed and recommend a continuation with this effort.

Diode and method of making the same

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

Dickerson, Jeramy Ray; Wierer, Jr., Jonathan; Kaplar, Robert

2018-03-13

A diode includes a second semiconductor layer over a first semiconductor layer. The diode further includes a third semiconductor layer over the second semiconductor layer, where the third semiconductor layer includes a first semiconductor element over the second semiconductor layer. The third semiconductor layer additionally includes a second semiconductor element over the second semiconductor layer, wherein the second semiconductor element surrounds the first semiconductor element. Further, the third semiconductor layer includes a third semiconductor element over the second semiconductor element. Furthermore, a hole concentration of the second semiconductor element is less than a hole concentration of the first semiconductor element.

Validity, reliability and feasibility of commercially available activity trackers in physical therapy for people with a chronic disease: a study protocol of a mixed methods research.

PubMed

Beekman, Emmylou; Braun, Susy M; Ummels, Darcy; van Vijven, Kim; Moser, Albine; Beurskens, Anna J

2017-01-01

For older people and people with a chronic disease, physical activity provides health benefits. Patients and healthcare professionals can use commercially available activity trackers to objectively monitor (alterations in) activity levels and patterns and to support physical activity. However, insight in the validity, reliability, and feasibility of these trackers in people with a chronic disease is needed. In this article, a study protocol is described in which the validity, reliability (part A), and feasibility from a patient and therapist's point of view (part B) of commercially available activity trackers in daily life and health care is investigated. In part A, a quantitative cross-sectional study, an activity protocol that simulates everyday life activities will be used to determine the validity and reliability of nine commercially available activity trackers. Video recordings will act as the gold standard. In part B, a qualitative participatory action research study will be performed to gain insight in the use of activity trackers in peoples' daily life and therapy settings. Objective feasibility of the activity trackers will be measured with questionnaires, and subjective feasibility (experiences) will be explored in a community of practice. Physical therapists ( n  = 8) will regularly meet during 6 months to learn from each other regarding the actual use of activity trackers in therapy. Therapists and patients ( n  = 48) will decide together which tracker will be used in therapy and for which purpose (e.g., monitoring, goal setting). Data from the therapist' and patients' experiences will be collected by interviews (individual and focus groups) and analyzed by a directed content analysis. At the time of submission, selection of activity trackers, development of the activity protocol, and the ethical approval process are finished. Data collection and data processing are ongoing. The relevance of the study as well as the advantages and disadvantages of several aspects of the chosen design are discussed. The results acquired from both study parts can be used to create decision aids that may assist therapists and people with a chronic disease in choosing a suitable activity tracker, and to facilitate use of these activity trackers in health care settings. Ethical approval has been obtained from two medical-ethical committees (nr. 15-N-109, 15-N-48 and MEC-15-07).

Grumman S2F-1 Tracker at NACA Lewis

NASA Image and Video Library

1956-08-21

The NACA’s Lewis Flight Propulsion Laboratory acquired the Grumman S2F-1 Tracker from the Navy in 1955 to study icing instrumentation. Lewis’s icing research program was winding down at the time. The use of jet engines was increasing thus reducing the threat of ice accumulation. Nonetheless Lewis continued research on the instrumentation used to detect icing conditions. The S2F-1 Tracker was a carrier-based submarine hunter for the Navy. Grumman developed the Tracker as a successor to its Korean War-era Guardian patrol aircraft. Prototypes first flew in late 1952 and battle-ready versions entered Naval service in early 1954. The Navy utilized the Trackers to protect fleets from attack.

Geometric Model for Tracker-Target Look Angles and Line of Slight Distance

DTIC Science & Technology

2015-10-20

412TW-PA-15239 Geometric Model for Tracker -Target Look Angles and Line of Slight Distance DANIEL T. LAIRD AIR FORCE TEST CENTER EDWARDS...15 – 23 OCT 15 4. TITLE AND SUBTITLE Geometric Model for Tracker -Target Look Angles and Line of Slight Distance 5a. CONTRACT...include area code) 661-277-8615 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 GEOMETRIC MODEL FOR TRACKER -TARGET LOOK ANGLES

Integration of an Apple II Plus Computer into an Existing Dual Axis Sun Tracker System.

DTIC Science & Technology

1984-06-01

Identify by block number) S, tpec l Sun Tracker System Solar Energy Apple II Plus Computer 20. ABSTRACT (’ ntlnue on reveree ide If neceesery end...14 4. Dual Axis Sun Tracker (Side View) ----------------- 15 5. Solar Tracker System Block Diagram ---------------- 17 6. Plug Wiring Diagram for Top...sources will be competitive. Already many homes have solar collectors and other devices designed to decrease the consumption of gas, oil, and

Counting Steps in Activities of Daily Living in People With a Chronic Disease Using Nine Commercially Available Fitness Trackers: Cross-Sectional Validity Study.

PubMed

Ummels, Darcy; Beekman, Emmylou; Theunissen, Kyra; Braun, Susy; Beurskens, Anna J

2018-04-02

Measuring physical activity with commercially available activity trackers is gaining popularity. People with a chronic disease can especially benefit from knowledge about their physical activity pattern in everyday life since sufficient physical activity can contribute to wellbeing and quality of life. However, no validity data are available for this population during activities of daily living. The aim of this study was to investigate the validity of 9 commercially available activity trackers for measuring step count during activities of daily living in people with a chronic disease receiving physiotherapy. The selected activity trackers were Accupedo (Corusen LLC), Activ8 (Remedy Distribution Ltd), Digi-Walker CW-700 (Yamax), Fitbit Flex (Fitbit inc), Lumoback (Lumo Bodytech), Moves (ProtoGeo Oy), Fitbit One (Fitbit inc), UP24 (Jawbone), and Walking Style X (Omron Healthcare Europe BV). In total, 130 persons with chronic diseases performed standardized activity protocols based on activities of daily living that were recorded on video camera and analyzed for step count (gold standard). The validity of the trackers' step count was assessed by correlation coefficients, t tests, scatterplots, and Bland-Altman plots. The correlations between the number of steps counted by the activity trackers and the gold standard were low (range: -.02 to .33). For all activity trackers except for Fitbit One, a significant systematic difference with the gold standard was found for step count. Plots showed a wide range in scores for all activity trackers; Activ8 showed an average overestimation and the other 8 trackers showed underestimations. This study showed that the validity of 9 commercially available activity trackers is low measuring steps while individuals with chronic diseases receiving physiotherapy engage in activities of daily living. ©Darcy Ummels, Emmylou Beekman, Kyra Theunissen, Susy Braun, Anna J Beurskens. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 02.04.2018.

Co-training Framework of Generative and Disciminative Trackers with Partial Occlusion Handling

DTIC Science & Technology

2011-01-01

ARO W911NF-06-1-0094. The first author was also supported by the Vietnam Education Foundation. We thank Zdenek Kalal for his help with the P-N Tracker...handling challenging situations with cluttered background. Recently, Kalal et al. [11] proposed the P-N Tracker us- ing positive and negative constraints to...Vietnam Education Foundation. We thank Zdenek Kalal for his help with the P-N Tracker [11]. References [1] A. Adam, E. Rivlin, and I. Shimshoni. Robust

Measuring Scale Errors in a Laser Tracker’s Horizontal Angle Encoder Through Simple Length Measurement and Two-Face System Tests

PubMed Central

Muralikrishnan, B.; Blackburn, C.; Sawyer, D.; Phillips, S.; Bridges, R.

2010-01-01

We describe a method to estimate the scale errors in the horizontal angle encoder of a laser tracker in this paper. The method does not require expensive instrumentation such as a rotary stage or even a calibrated artifact. An uncalibrated but stable length is realized between two targets mounted on stands that are at tracker height. The tracker measures the distance between these two targets from different azimuthal positions (say, in intervals of 20° over 360°). Each target is measured in both front face and back face. Low order harmonic scale errors can be estimated from this data and may then be used to correct the encoder’s error map to improve the tracker’s angle measurement accuracy. We have demonstrated this for the second order harmonic in this paper. It is important to compensate for even order harmonics as their influence cannot be removed by averaging front face and back face measurements whereas odd orders can be removed by averaging. We tested six trackers from three different manufacturers. Two of those trackers are newer models introduced at the time of writing of this paper. For older trackers from two manufacturers, the length errors in a 7.75 m horizontal length placed 7 m away from a tracker were of the order of ± 65 μm before correcting the error map. They reduced to less than ± 25 μm after correcting the error map for second order scale errors. Newer trackers from the same manufacturers did not show this error. An older tracker from a third manufacturer also did not show this error. PMID:27134789

Counting Steps in Activities of Daily Living in People With a Chronic Disease Using Nine Commercially Available Fitness Trackers: Cross-Sectional Validity Study

PubMed Central

Beekman, Emmylou; Theunissen, Kyra; Braun, Susy; Beurskens, Anna J

2018-01-01

Background Measuring physical activity with commercially available activity trackers is gaining popularity. People with a chronic disease can especially benefit from knowledge about their physical activity pattern in everyday life since sufficient physical activity can contribute to wellbeing and quality of life. However, no validity data are available for this population during activities of daily living. Objective The aim of this study was to investigate the validity of 9 commercially available activity trackers for measuring step count during activities of daily living in people with a chronic disease receiving physiotherapy. Methods The selected activity trackers were Accupedo (Corusen LLC), Activ8 (Remedy Distribution Ltd), Digi-Walker CW-700 (Yamax), Fitbit Flex (Fitbit inc), Lumoback (Lumo Bodytech), Moves (ProtoGeo Oy), Fitbit One (Fitbit inc), UP24 (Jawbone), and Walking Style X (Omron Healthcare Europe BV). In total, 130 persons with chronic diseases performed standardized activity protocols based on activities of daily living that were recorded on video camera and analyzed for step count (gold standard). The validity of the trackers’ step count was assessed by correlation coefficients, t tests, scatterplots, and Bland-Altman plots. Results The correlations between the number of steps counted by the activity trackers and the gold standard were low (range: –.02 to .33). For all activity trackers except for Fitbit One, a significant systematic difference with the gold standard was found for step count. Plots showed a wide range in scores for all activity trackers; Activ8 showed an average overestimation and the other 8 trackers showed underestimations. Conclusions This study showed that the validity of 9 commercially available activity trackers is low measuring steps while individuals with chronic diseases receiving physiotherapy engage in activities of daily living. PMID:29610110

Reliability and Validity of Ten Consumer Activity Trackers Depend on Walking Speed.

PubMed

Fokkema, Tryntsje; Kooiman, Thea J M; Krijnen, Wim P; VAN DER Schans, Cees P; DE Groot, Martijn

2017-04-01

To examine the test-retest reliability and validity of ten activity trackers for step counting at three different walking speeds. Thirty-one healthy participants walked twice on a treadmill for 30 min while wearing 10 activity trackers (Polar Loop, Garmin Vivosmart, Fitbit Charge HR, Apple Watch Sport, Pebble Smartwatch, Samsung Gear S, Misfit Flash, Jawbone Up Move, Flyfit, and Moves). Participants walked three walking speeds for 10 min each; slow (3.2 km·h), average (4.8 km·h), and vigorous (6.4 km·h). To measure test-retest reliability, intraclass correlations (ICC) were determined between the first and second treadmill test. Validity was determined by comparing the trackers with the gold standard (hand counting), using mean differences, mean absolute percentage errors, and ICC. Statistical differences were calculated by paired-sample t tests, Wilcoxon signed-rank tests, and by constructing Bland-Altman plots. Test-retest reliability varied with ICC ranging from -0.02 to 0.97. Validity varied between trackers and different walking speeds with mean differences between the gold standard and activity trackers ranging from 0.0 to 26.4%. Most trackers showed relatively low ICC and broad limits of agreement of the Bland-Altman plots at the different speeds. For the slow walking speed, the Garmin Vivosmart and Fitbit Charge HR showed the most accurate results. The Garmin Vivosmart and Apple Watch Sport demonstrated the best accuracy at an average walking speed. For vigorous walking, the Apple Watch Sport, Pebble Smartwatch, and Samsung Gear S exhibited the most accurate results. Test-retest reliability and validity of activity trackers depends on walking speed. In general, consumer activity trackers perform better at an average and vigorous walking speed than at a slower walking speed.

Individual Differences in the Attribution of Incentive Salience to a Pavlovian Alcohol Cue.

PubMed

Villaruel, Franz R; Chaudhri, Nadia

2016-01-01

Individual differences exist in the attribution of incentive salience to conditioned stimuli associated with food. Here, we investigated whether individual differences also manifested with a Pavlovian alcohol conditioned stimulus (CS). We compiled data from five experiments that used a Pavlovian autoshaping paradigm and tests of conditioned reinforcement. In all experiments, male, Long-Evans rats with unrestricted access to food and water were acclimated to 15% ethanol. Next, rats received Pavlovian autoshaping training, in which a 10 s presentation of a retractable lever served as the CS and 0.2 mL of 15% ethanol served as the unconditioned stimulus (US). Finally, rats underwent conditioned reinforcement tests in which nose-pokes to an active aperture led to brief presentations of the lever-CS, but nose-pokes to an inactive aperture had no consequence. Rats were categorized as sign-trackers, goal-trackers and intermediates based on a response bias score that reflected their tendencies to sign-track or goal-track at different times during training. We found that distinct groups of rats either consistently interacted with the lever-CS ("sign-trackers") or routinely approached the port during the lever-CS ("goal-trackers") across a majority of the training sessions. However, some individuals ("shifted sign-trackers") with an early tendency to goal-track later shifted to comparable asymptotic levels of sign-tracking as the group identified as sign-trackers. The lever-CS functioned as a conditioned reinforcer for sign-trackers and shifted sign-trackers, but not for goal-trackers. These results provide evidence of robust individual differences in the extent to which a Pavlovian alcohol cue gains incentive salience and functions as a conditioned reinforcer.

Precision Attitude Determination System (PADS) design and analysis. Two-axis gimbal star tracker

NASA Technical Reports Server (NTRS)

1973-01-01

Development of the Precision Attitude Determination System (PADS) focused chiefly on the two-axis gimballed star tracker and electronics design improved from that of Precision Pointing Control System (PPCS), and application of the improved tracker for PADS at geosynchronous altitude. System design, system analysis, software design, and hardware design activities are reported. The system design encompasses the PADS configuration, system performance characteristics, component design summaries, and interface considerations. The PADS design and performance analysis includes error analysis, performance analysis via attitude determination simulation, and star tracker servo design analysis. The design of the star tracker and electronics are discussed. Sensor electronics schematics are included. A detailed characterization of the application software algorithms and computer requirements is provided.

Sun tracker for clear or cloudy weather

NASA Technical Reports Server (NTRS)

Scott, D. R.; White, P. R.

1979-01-01

Sun tracker orients solar collector so that they absorb maximum possible sunlight without being fooled by bright clouds, holes in cloud cover, or other atmospheric conditions. Tracker follows sun within 0.25 deg arc and is accurate within + or - 5 deg when sun is hidden.

Advantages and Limitations of Wearable Activity Trackers: Considerations for Patients and Clinicians.

PubMed

Walker, Rachel K; Hickey, Amanda M; Freedson, Patty S

2016-12-01

Exercise, light physical activity, and decreased sedentary time all have been associated with health benefits following cancer diagnoses. Commercially available wearable activity trackers may help patients monitor and self-manage their behaviors to achieve these benefits. This article highlights some advantages and limitations clinicians should be aware of when discussing the use of activity trackers with cancer survivors. Limited research has assessed the accuracy of commercially available activity trackers compared to research-grade devices. Because most devices use confidential, proprietary algorithms to convert accelerometry data to meaningful output like total steps, assessing whether these algorithms account for differences in gait abnormalities, functional limitations, and different body morphologies can be difficult. Quantification of sedentary behaviors and light physical activities present additional challenges. The global market for activity trackers is growing, which presents clinicians with a tremendous opportunity to incorporate these devices into clinical practice as tools to promote activity. This article highlights important considerations about tracker accuracy and usage by cancer survivors.

Spacecraft angular velocity estimation algorithm for star tracker based on optical flow techniques

NASA Astrophysics Data System (ADS)

Tang, Yujie; Li, Jian; Wang, Gangyi

2018-02-01

An integrated navigation system often uses the traditional gyro and star tracker for high precision navigation with the shortcomings of large volume, heavy weight and high-cost. With the development of autonomous navigation for deep space and small spacecraft, star tracker has been gradually used for attitude calculation and angular velocity measurement directly. At the same time, with the dynamic imaging requirements of remote sensing satellites and other imaging satellites, how to measure the angular velocity in the dynamic situation to improve the accuracy of the star tracker is the hotspot of future research. We propose the approach to measure angular rate with a nongyro and improve the dynamic performance of the star tracker. First, the star extraction algorithm based on morphology is used to extract the star region, and the stars in the two images are matched according to the method of angular distance voting. The calculation of the displacement of the star image is measured by the improved optical flow method. Finally, the triaxial angular velocity of the star tracker is calculated by the star vector using the least squares method. The method has the advantages of fast matching speed, strong antinoise ability, and good dynamic performance. The triaxial angular velocity of star tracker can be obtained accurately with these methods. So, the star tracker can achieve better tracking performance and dynamic attitude positioning accuracy to lay a good foundation for the wide application of various satellites and complex space missions.

Experimental predictions drawn from a computational model of sign-trackers and goal-trackers.

PubMed

Lesaint, Florian; Sigaud, Olivier; Clark, Jeremy J; Flagel, Shelly B; Khamassi, Mehdi

2015-01-01

Gaining a better understanding of the biological mechanisms underlying the individual variation observed in response to rewards and reward cues could help to identify and treat individuals more prone to disorders of impulsive control, such as addiction. Variation in response to reward cues is captured in rats undergoing autoshaping experiments where the appearance of a lever precedes food delivery. Although no response is required for food to be delivered, some rats (goal-trackers) learn to approach and avidly engage the magazine until food delivery, whereas other rats (sign-trackers) come to approach and engage avidly the lever. The impulsive and often maladaptive characteristics of the latter response are reminiscent of addictive behaviour in humans. In a previous article, we developed a computational model accounting for a set of experimental data regarding sign-trackers and goal-trackers. Here we show new simulations of the model to draw experimental predictions that could help further validate or refute the model. In particular, we apply the model to new experimental protocols such as injecting flupentixol locally into the core of the nucleus accumbens rather than systemically, and lesioning of the core of the nucleus accumbens before or after conditioning. In addition, we discuss the possibility of removing the food magazine during the inter-trial interval. The predictions from this revised model will help us better understand the role of different brain regions in the behaviours expressed by sign-trackers and goal-trackers. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-power free-electron lasers-technology and future applications

NASA Astrophysics Data System (ADS)

Socol, Yehoshua

2013-03-01

Free-electron laser (FEL) is an all-electric, high-power, high beam-quality source of coherent radiation, tunable - unlike other laser sources - at any wavelength within wide spectral region from hard X-rays to far-IR and beyond. After the initial push in the framework of the “Star Wars” program, the FEL technology benefited from decades of R&D and scientific applications. Currently, there are clear signs that the FEL technology reached maturity, enabling real-world applications. E.g., successful and unexpectedly smooth commissioning of the world-first X-ray FEL in 2010 increased in one blow by more than an order of magnitude (40×) wavelength region available by FEL technology and thus demonstrated that the theoretical predictions just keep true in real machines. Experience of ordering turn-key electron beamlines from commercial companies is a further demonstration of the FEL technology maturity. Moreover, successful commissioning of the world-first multi-turn energy-recovery linac demonstrated feasibility of reducing FEL size, cost and power consumption by probably an order of magnitude in respect to previous configurations, opening way to applications, previously considered as non-feasible. This review takes engineer-oriented approach to discuss the FEL technology issues, keeping in mind applications in the fields of military and aerospace, next generation semiconductor lithography, photo-chemistry and isotope separation.

Post flight analysis of NASA standard star trackers recovered from the solar maximum mission

NASA Technical Reports Server (NTRS)

Newman, P.

1985-01-01

The flight hardware returned after the Solar Maximum Mission Repair Mission was analyzed to determine the effects of 4 years in space. The NASA Standard Star Tracker would be a good candidate for such analysis because it is moderately complex and had a very elaborate calibration during the acceptance procedure. However, the recovery process extensively damaged the cathode of the image dissector detector making proper operation of the tracker and a comparison with preflight characteristics impossible. Otherwise, the tracker functioned nominally during testing.

Personal Activity Trackers and the Quantified Self.

PubMed

Hoy, Matthew B

2016-01-01

Personal activity trackers are an inexpensive and easy way for people to record their physical activity and simple biometric data. As these devices have increased in availability and sophistication, their use in daily life and in medicine has grown. This column will briefly explore what these devices are, what types of data they can track, and how that data can be used. It will also discuss potential problems with trackers and how librarians can help patients and physicians manage and protect activity data. A brief list of currently available activity trackers is also included.

One-kilohertz eye tracker and active intraoperative torsion detection in the NIDEK CXIII and Quest excimer lasers.

PubMed

Waring, George O

2009-10-01

To describe recent technological additions to the NIDEK CXIII and Quest excimer lasers. A summary article with data from previous published studies outlining the benefits of newer technology. The addition of a 1-kHz infrared eye tracker decreased the spread of laser spot placement from a mean of 228.79 microm without a tracker to 38.47 microm with the eye tracker. The addition of real-time torsion error correction produced a statistically significantly lower cylinder dispersion, mean manifest refractive cylinder, and error of angle postoperatively in eyes that underwent LASIK. The incorporation of an ultrahigh speed eye tracker and active cyclotorsion correction surpasses the minimal technology criteria required for accurate wavefront-based ablations. Copyright 2009, SLACK Incorporated.

Log-polar mapping-based scale space tracking with adaptive target response

NASA Astrophysics Data System (ADS)

Li, Dongdong; Wen, Gongjian; Kuai, Yangliu; Zhang, Ximing

2017-05-01

Correlation filter-based tracking has exhibited impressive robustness and accuracy in recent years. Standard correlation filter-based trackers are restricted to translation estimation and equipped with fixed target response. These trackers produce an inferior performance when encountered with a significant scale variation or appearance change. We propose a log-polar mapping-based scale space tracker with an adaptive target response. This tracker transforms the scale variation of the target in the Cartesian space into a shift along the logarithmic axis in the log-polar space. A one-dimensional scale correlation filter is learned online to estimate the shift along the logarithmic axis. With the log-polar representation, scale estimation is achieved accurately without a multiresolution pyramid. To achieve an adaptive target response, a variance of the Gaussian function is computed from the response map and updated online with a learning rate parameter. Our log-polar mapping-based scale correlation filter and adaptive target response can be combined with any correlation filter-based trackers. In addition, the scale correlation filter can be extended to a two-dimensional correlation filter to achieve joint estimation of the scale variation and in-plane rotation. Experiments performed on an OTB50 benchmark demonstrate that our tracker achieves superior performance against state-of-the-art trackers.

Infant Eyes: A Window on Cognitive Development

ERIC Educational Resources Information Center

Aslin, Richard N.

2012-01-01

Eye-trackers suitable for use with infants are now marketed by several commercial vendors. As eye-trackers become more prevalent in infancy research, there is the potential for users to be unaware of dangers lurking "under the hood" if they assume the eye-tracker introduces no errors in measuring infants' gaze. Moreover, the influx of voluminous…

Analyzing Virtual Physics Simulations with Tracker

ERIC Educational Resources Information Center

Claessens, Tom

2017-01-01

In the physics teaching community, Tracker is well known as a user-friendly open source video analysis software, authored by Douglas Brown. With this tool, the user can trace markers indicated on a video or on stroboscopic photos and perform kinematic analyses. Tracker also includes a data modeling tool that allows one to fit some theoretical…

Space Shuttle Star Tracker Challenges

NASA Technical Reports Server (NTRS)

Herrera, Linda M.

2010-01-01

The space shuttle fleet of avionics was originally designed in the 1970's. Many of the subsystems have been upgraded and replaced, however some original hardware continues to fly. Not only fly, but has proven to be the best design available to perform its designated task. The shuttle star tracker system is currently flying as a mixture of old and new designs, each with a unique purpose to fill for the mission. Orbiter missions have tackled many varied missions in space over the years. As the orbiters began flying to the International Space Station (ISS), new challenges were discovered and overcome as new trusses and modules were added. For the star tracker subsystem, the growing ISS posed an unusual problem, bright light. With two star trackers on board, the 1970's vintage image dissector tube (IDT) star trackers track the ISS, while the new solid state design is used for dim star tracking. This presentation focuses on the challenges and solutions used to ensure star trackers can complete the shuttle missions successfully. Topics include KSC team and industry partner methods used to correct pressurized case failures and track system performance.

A low-cost, CCD solid state star tracker

NASA Technical Reports Server (NTRS)

Chmielowski, M.; Wynne, D.

1992-01-01

Applied Research Corporation (ARC) has developed an engineering model of a multi-star CCD-based tracker for space applications requiring radiation hardness, high reliability and low power consumption. The engineering unit compared favorably in functional performance tests to the standard NASA single-star tracker. Characteristics of the ARC star tracker are: field of view = 10 deg x 7.5 deg, sensitivity range of -1 to +5 star magnitude, NEA = 3 in x 3 in, linearity = 5 in x 5 in, and power consumption of 1-3 W (operating mode dependent). The software is upgradable through a remote link. The hardware-limited acquisition rate is 1-5 Hz for stars of +2 to +5 magnitude and 10-30 Hz for -1 to +2 magnitude stars. Mechanical and electrical interfaces are identical to the standard NASA star tracker.

Intelligent error correction method applied on an active pixel sensor based star tracker

NASA Astrophysics Data System (ADS)

Schmidt, Uwe

2005-10-01

Star trackers are opto-electronic sensors used on-board of satellites for the autonomous inertial attitude determination. During the last years star trackers became more and more important in the field of the attitude and orbit control system (AOCS) sensors. High performance star trackers are based up today on charge coupled device (CCD) optical camera heads. The active pixel sensor (APS) technology, introduced in the early 90-ties, allows now the beneficial replacement of CCD detectors by APS detectors with respect to performance, reliability, power, mass and cost. The company's heritage in star tracker design started in the early 80-ties with the launch of the worldwide first fully autonomous star tracker system ASTRO1 to the Russian MIR space station. Jena-Optronik recently developed an active pixel sensor based autonomous star tracker "ASTRO APS" as successor of the CCD based star tracker product series ASTRO1, ASTRO5, ASTRO10 and ASTRO15. Key features of the APS detector technology are, a true xy-address random access, the multiple windowing read out and the on-chip signal processing including the analogue to digital conversion. These features can be used for robust star tracking at high slew rates and under worse conditions like stray light and solar flare induced single event upsets. A special algorithm have been developed to manage the typical APS detector error contributors like fixed pattern noise (FPN), dark signal non-uniformity (DSNU) and white spots. The algorithm works fully autonomous and adapts to e.g. increasing DSNU and up-coming white spots automatically without ground maintenance or re-calibration. In contrast to conventional correction methods the described algorithm does not need calibration data memory like full image sized calibration data sets. The application of the presented algorithm managing the typical APS detector error contributors is a key element for the design of star trackers for long term satellite applications like geostationary telecom platforms.

Reliability and validity of ten consumer activity trackers.

PubMed

Kooiman, Thea J M; Dontje, Manon L; Sprenger, Siska R; Krijnen, Wim P; van der Schans, Cees P; de Groot, Martijn

2015-01-01

Activity trackers can potentially stimulate users to increase their physical activity behavior. The aim of this study was to examine the reliability and validity of ten consumer activity trackers for measuring step count in both laboratory and free-living conditions. Healthy adult volunteers (n = 33) walked twice on a treadmill (4.8 km/h) for 30 min while wearing ten different activity trackers (i.e. Lumoback, Fitbit Flex, Jawbone Up, Nike+ Fuelband SE, Misfit Shine, Withings Pulse, Fitbit Zip, Omron HJ-203, Yamax Digiwalker SW-200 and Moves mobile application). In free-living conditions, 56 volunteers wore the same activity trackers for one working day. Test-retest reliability was analyzed with the Intraclass Correlation Coefficient (ICC). Validity was evaluated by comparing each tracker with the gold standard (Optogait system for laboratory and ActivPAL for free-living conditions), using paired samples t-tests, mean absolute percentage errors, correlations and Bland-Altman plots. Test-retest analysis revealed high reliability for most trackers except for the Omron (ICC .14), Moves app (ICC .37) and Nike+ Fuelband (ICC .53). The mean absolute percentage errors of the trackers in laboratory and free-living conditions respectively, were: Lumoback (-0.2, -0.4), Fibit Flex (-5.7, 3.7), Jawbone Up (-1.0, 1.4), Nike+ Fuelband (-18, -24), Misfit Shine (0.2, 1.1), Withings Pulse (-0.5, -7.9), Fitbit Zip (-0.3, 1.2), Omron (2.5, -0.4), Digiwalker (-1.2, -5.9), and Moves app (9.6, -37.6). Bland-Altman plots demonstrated that the limits of agreement varied from 46 steps (Fitbit Zip) to 2422 steps (Nike+ Fuelband) in the laboratory condition, and 866 steps (Fitbit Zip) to 5150 steps (Moves app) in the free-living condition. The reliability and validity of most trackers for measuring step count is good. The Fitbit Zip is the most valid whereas the reliability and validity of the Nike+ Fuelband is low.

Development of the FitSight Fitness Tracker to Increase Time Outdoors to Prevent Myopia.

PubMed

Verkicharla, Pavan K; Ramamurthy, Dharani; Nguyen, Quang Duc; Zhang, Xinquan; Pu, Suan-Hui; Malhotra, Rahul; Ostbye, Truls; Lamoureux, Ecosse L; Saw, Seang-Mei

2017-06-01

To develop a fitness tracker (FitSight) to encourage children to increase time spent outdoors. To evaluate the wear pattern for this tracker and outdoor time pattern by estimating light illumination levels among children. The development of the FitSight fitness tracker involved the designing of two components: (1) the smartwatch with custom-made FitSight watch application (app) to log the instant light illuminance levels the wearer is exposed to, and (2) a companion smartphone app that synchronizes the time outdoors recorded by the smartwatch to smartphone via Bluetooth communication. Smartwatch wear patterns and tracker-recorded daily light illuminance levels data were gathered over 7 days from 23 Singapore children (mean ± standard deviation age: 9.2 ± 1.4 years). Feedback about the tracker was obtained from 14 parents using a three-level rating scale: very poor/poor/good. Of the 14 parents, 93% rated the complete "FitSight fitness tracker" as good and 64% rated its wearability as good. While 61% of 23 children wore the watch on all study days (i.e., 0 nonwear days), 26% had 1 nonwear day, and 4.5% children each had 3, 4, and 5 nonwear days, respectively. On average, children spent approximately 1 hour in light levels greater than 1000 lux on weekdays and 1.3 hours on weekends (60 ± 46 vs. 79 ± 53 minutes, P = 0.19). Mean number of outdoor "spurts" (light illuminance levels >1000 lux) per day was 8 ± 3 spurts with spurt duration of 34 ± 32 minutes. The FitSight tracker with its novel features may motivate children to increase time outdoors and play an important role in supplementing community outdoor programs to prevent myopia. If the developed noninvasive, wearable, smartwatch-based fitness tracker, FitSight, promotes daytime outdoor activity among children, it will be beneficial in addressing the epidemic of myopia.

Compensation for Time-Dependent Star Tracker Thermal Deformation on the Aqua Spacecraft

NASA Technical Reports Server (NTRS)

Hashmall, Joseph A.; Natanson, Gregory; Glickman, Jonathan; Sedlak, Joseph

2004-01-01

Analysis of attitude sensor data from the Aqua mission showed small but systematic differences between batch least-squares and extended Kalman filter attitudes. These differences were also found to be correlated with star tracker residuals, gyro bias estimates, and star tracker baseplate temperatures. This paper describes the analysis that shows that these correlations are all consistent with a single cause: time-dependent thermal deformation of star tracker alignments. These varying alignments can be separated into relative and common components. The relative misalignments can be determined and compensated for. The common misalignments can only be determined in special cases.

Users' experiences of wearable activity trackers: a cross-sectional study.

PubMed

Maher, Carol; Ryan, Jillian; Ambrosi, Christina; Edney, Sarah

2017-11-15

Wearable activity trackers offer considerable promise for helping users to adopt healthier lifestyles. This study aimed to explore users' experience of activity trackers, including usage patterns, sharing of data to social media, perceived behaviour change (physical activity, diet and sleep), and technical issues/barriers to use. A cross-sectional online survey was developed and administered to Australian adults who were current or former activity tracker users. Results were analysed descriptively, with differences between current and former users and wearable brands explored using independent samples t-tests, Mann-Whitney, and chi square tests. Participants included 200 current and 37 former activity tracker users (total N = 237) with a mean age of 33.1 years (SD 12.4, range 18-74 years). Fitbit (67.5%) and Garmin devices (16.5%) were most commonly reported. Participants typically used their trackers for sustained periods (5-7 months) and most intended to continue usage. Participants reported they had improved their physical activity (51-81%) more commonly than they had their diet (14-40%) or sleep (11-24%), and slightly more participants reported to value the real time feedback (89%) compared to the long-term monitoring (78%). Most users (70%) reported they had experienced functionality issues with their devices, most commonly related to battery life and technical difficulties. Results suggest users find activity trackers appealing and useful tools for increasing perceived physical activity levels over a sustained period.

Analysis of the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery☆

PubMed Central

Arba-Mosquera, Samuel; Aslanides, Ioannis M.

2012-01-01

Purpose To analyze the effects of Eye-Tracker performance on the pulse positioning errors during refractive surgery. Methods A comprehensive model, which directly considers eye movements, including saccades, vestibular, optokinetic, vergence, and miniature, as well as, eye-tracker acquisition rate, eye-tracker latency time, scanner positioning time, laser firing rate, and laser trigger delay have been developed. Results Eye-tracker acquisition rates below 100 Hz correspond to pulse positioning errors above 1.5 mm. Eye-tracker latency times to about 15 ms correspond to pulse positioning errors of up to 3.5 mm. Scanner positioning times to about 9 ms correspond to pulse positioning errors of up to 2 mm. Laser firing rates faster than eye-tracker acquisition rates basically duplicate pulse-positioning errors. Laser trigger delays to about 300 μs have minor to no impact on pulse-positioning errors. Conclusions The proposed model can be used for comparison of laser systems used for ablation processes. Due to the pseudo-random nature of eye movements, positioning errors of single pulses are much larger than observed decentrations in the clinical settings. There is no single parameter that ‘alone’ minimizes the positioning error. It is the optimal combination of the several parameters that minimizes the error. The results of this analysis are important to understand the limitations of correcting very irregular ablation patterns.

Collaborative engineering and design management for the Hobby-Eberly Telescope tracker upgrade

NASA Astrophysics Data System (ADS)

Mollison, Nicholas T.; Hayes, Richard J.; Good, John M.; Booth, John A.; Savage, Richard D.; Jackson, John R.; Rafal, Marc D.; Beno, Joseph H.

2010-07-01

The engineering and design of systems as complex as the Hobby-Eberly Telescope's* new tracker require that multiple tasks be executed in parallel and overlapping efforts. When the design of individual subsystems is distributed among multiple organizations, teams, and individuals, challenges can arise with respect to managing design productivity and coordinating successful collaborative exchanges. This paper focuses on design management issues and current practices for the tracker design portion of the Hobby-Eberly Telescope Wide Field Upgrade project. The scope of the tracker upgrade requires engineering contributions and input from numerous fields including optics, instrumentation, electromechanics, software controls engineering, and site-operations. Successful system-level integration of tracker subsystems and interfaces is critical to the telescope's ultimate performance in astronomical observation. Software and process controls for design information and workflow management have been implemented to assist the collaborative transfer of tracker design data. The tracker system architecture and selection of subsystem interfaces has also proven to be a determining factor in design task formulation and team communication needs. Interface controls and requirements change controls will be discussed, and critical team interactions are recounted (a group-participation Failure Modes and Effects Analysis [FMEA] is one of special interest). This paper will be of interest to engineers, designers, and managers engaging in multi-disciplinary and parallel engineering projects that require coordination among multiple individuals, teams, and organizations.

User Acceptance of Wrist-Worn Activity Trackers Among Community-Dwelling Older Adults: Mixed Method Study

PubMed Central

Puri, Arjun; Kim, Ben; Nguyen, Olivier; Stolee, Paul; Tung, James

2017-01-01

Background Wearable activity trackers are newly emerging technologies with the anticipation for successfully supporting aging-in-place. Consumer-grade wearable activity trackers are increasingly ubiquitous in the market, but the attitudes toward, as well as acceptance and voluntary use of, these trackers in older population are poorly understood. Objective The aim of this study was to assess acceptance and usage of wearable activity trackers in Canadian community-dwelling older adults, using the potentially influential factors as identified in literature and technology acceptance model. Methods A mixed methods design was used. A total of 20 older adults aged 55 years and older were recruited from Southwestern Ontario. Participants used 2 different wearable activity trackers (Xiaomi Mi Band and Microsoft Band) separately for each segment in the crossover design study for 21 days (ie, 42 days total). A questionnaire was developed to capture acceptance and experience at the end of each segment, representing 2 different devices. Semistructured interviews were conducted with 4 participants, and a content analysis was performed. Results Participants ranged in age from 55 years to 84 years (mean age: 64 years). The Mi Band gained higher levels of acceptance (16/20, 80%) compared with the Microsoft Band (10/20, 50%). The equipment characteristics dimension scored significantly higher for the Mi Band (P<.05). The amount a participant was willing to pay for the device was highly associated with technology acceptance (P<.05). Multivariate logistic regression with 3 covariates resulted in an area under the curve of 0.79. Content analysis resulted in the formation of the following main themes: (1) smartphones as facilitators of wearable activity trackers; (2) privacy is less of a concern for wearable activity trackers, (3) value proposition: self-awareness and motivation; (4) subjective norm, social support, and sense of independence; and (5) equipment characteristics matter: display, battery, comfort, and aesthetics. Conclusions Older adults were mostly accepting of wearable activity trackers, and they had a clear understanding of its value for their lives. Wearable activity trackers were uniquely considered more personal than other types of technologies, thereby the equipment characteristics including comfort, aesthetics, and price had a significant impact on the acceptance. Results indicated that privacy was less of concern for older adults, but it may have stemmed from a lack of understanding of the privacy risks and implications. These findings add to emerging research that investigates acceptance and factors that may influence acceptance of wearable activity trackers among older adults. PMID:29141837

Cross modality registration of video and magnetic tracker data for 3D appearance and structure modeling

NASA Astrophysics Data System (ADS)

Sargent, Dusty; Chen, Chao-I.; Wang, Yuan-Fang

2010-02-01

The paper reports a fully-automated, cross-modality sensor data registration scheme between video and magnetic tracker data. This registration scheme is intended for use in computerized imaging systems to model the appearance, structure, and dimension of human anatomy in three dimensions (3D) from endoscopic videos, particularly colonoscopic videos, for cancer research and clinical practices. The proposed cross-modality calibration procedure operates this way: Before a colonoscopic procedure, the surgeon inserts a magnetic tracker into the working channel of the endoscope or otherwise fixes the tracker's position on the scope. The surgeon then maneuvers the scope-tracker assembly to view a checkerboard calibration pattern from a few different viewpoints for a few seconds. The calibration procedure is then completed, and the relative pose (translation and rotation) between the reference frames of the magnetic tracker and the scope is determined. During the colonoscopic procedure, the readings from the magnetic tracker are used to automatically deduce the pose (both position and orientation) of the scope's reference frame over time, without complicated image analysis. Knowing the scope movement over time then allows us to infer the 3D appearance and structure of the organs and tissues in the scene. While there are other well-established mechanisms for inferring the movement of the camera (scope) from images, they are often sensitive to mistakes in image analysis, error accumulation, and structure deformation. The proposed method using a magnetic tracker to establish the camera motion parameters thus provides a robust and efficient alternative for 3D model construction. Furthermore, the calibration procedure does not require special training nor use expensive calibration equipment (except for a camera calibration pattern-a checkerboard pattern-that can be printed on any laser or inkjet printer).

Development and evaluation of a hand tracker using depth images captured from an overhead perspective.

PubMed

Czarnuch, Stephen; Mihailidis, Alex

2015-03-27

We present the development and evaluation of a robust hand tracker based on single overhead depth images for use in the COACH, an assistive technology for people with dementia. The new hand tracker was designed to overcome limitations experienced by the COACH in previous clinical trials. We train a random decision forest classifier using ∼5000 manually labeled, unbalanced, training images. Hand positions from the classifier are translated into task actions based on proximity to environmental objects. Tracker performance is evaluated using a large set of ∼24 000 manually labeled images captured from 41 participants in a fully-functional washroom, and compared to the system's previous colour-based hand tracker. Precision and recall were 0.994 and 0.938 for the depth tracker compared to 0.981 and 0.822 for the colour tracker with the current data, and 0.989 and 0.466 in the previous study. The improved tracking performance supports integration of the depth-based tracker into the COACH toward unsupervised, real-world trials. Implications for Rehabilitation The COACH is an intelligent assistive technology that can enable people with cognitive disabilities to stay at home longer, supporting the concept of aging-in-place. Automated prompting systems, a type of intelligent assistive technology, can help to support the independent completion of activities of daily living, increasing the independence of people with cognitive disabilities while reducing the burden of care experienced by caregivers. Robust motion tracking using depth imaging supports the development of intelligent assistive technologies like the COACH. Robust motion tracking also has application to other forms of assistive technologies including gaming, human-computer interaction and automated assessments.

Behavior Change Techniques Present in Wearable Activity Trackers: A Critical Analysis

PubMed Central

Mercer, Kathryn; Li, Melissa; Giangregorio, Lora; Burns, Catherine

2016-01-01

Background Wearable activity trackers are promising as interventions that offer guidance and support for increasing physical activity and health-focused tracking. Most adults do not meet their recommended daily activity guidelines, and wearable fitness trackers are increasingly cited as having great potential to improve the physical activity levels of adults. Objective The objective of this study was to use the Coventry, Aberdeen, and London-Refined (CALO-RE) taxonomy to examine if the design of wearable activity trackers incorporates behavior change techniques (BCTs). A secondary objective was to critically analyze whether the BCTs present relate to known drivers of behavior change, such as self-efficacy, with the intention of extending applicability to older adults in addition to the overall population. Methods Wearing each device for a period of 1 week, two independent raters used CALO-RE taxonomy to code the BCTs of the seven wearable activity trackers available in Canada as of March 2014. These included Fitbit Flex, Misfit Shine, Withings Pulse, Jawbone UP24, Spark Activity Tracker by SparkPeople, Nike+ FuelBand SE, and Polar Loop. We calculated interrater reliability using Cohen's kappa. Results The average number of BCTs identified was 16.3/40. Withings Pulse had the highest number of BCTs and Misfit Shine had the lowest. Most techniques centered around self-monitoring and self-regulation, all of which have been associated with improved physical activity in older adults. Techniques related to planning and providing instructions were scarce. Conclusions Overall, wearable activity trackers contain several BCTs that have been shown to increase physical activity in older adults. Although more research and development must be done to fully understand the potential of wearables as health interventions, the current wearable trackers offer significant potential with regard to BCTs relevant to uptake by all populations, including older adults. PMID:27122452

Behavior Change Techniques Present in Wearable Activity Trackers: A Critical Analysis.

PubMed

Mercer, Kathryn; Li, Melissa; Giangregorio, Lora; Burns, Catherine; Grindrod, Kelly

2016-04-27

Wearable activity trackers are promising as interventions that offer guidance and support for increasing physical activity and health-focused tracking. Most adults do not meet their recommended daily activity guidelines, and wearable fitness trackers are increasingly cited as having great potential to improve the physical activity levels of adults. The objective of this study was to use the Coventry, Aberdeen, and London-Refined (CALO-RE) taxonomy to examine if the design of wearable activity trackers incorporates behavior change techniques (BCTs). A secondary objective was to critically analyze whether the BCTs present relate to known drivers of behavior change, such as self-efficacy, with the intention of extending applicability to older adults in addition to the overall population. Wearing each device for a period of 1 week, two independent raters used CALO-RE taxonomy to code the BCTs of the seven wearable activity trackers available in Canada as of March 2014. These included Fitbit Flex, Misfit Shine, Withings Pulse, Jawbone UP24, Spark Activity Tracker by SparkPeople, Nike+ FuelBand SE, and Polar Loop. We calculated interrater reliability using Cohen's kappa. The average number of BCTs identified was 16.3/40. Withings Pulse had the highest number of BCTs and Misfit Shine had the lowest. Most techniques centered around self-monitoring and self-regulation, all of which have been associated with improved physical activity in older adults. Techniques related to planning and providing instructions were scarce. Overall, wearable activity trackers contain several BCTs that have been shown to increase physical activity in older adults. Although more research and development must be done to fully understand the potential of wearables as health interventions, the current wearable trackers offer significant potential with regard to BCTs relevant to uptake by all populations, including older adults.

IMM tracking of a theater ballistic missile during boost phase

NASA Astrophysics Data System (ADS)

Hutchins, Robert G.; San Jose, Anthony

1998-09-01

Since the SCUD launches in the Gulf War, theater ballistic missile (TBM) systems have become a growing concern for the US military. Detection, tracking and engagement during boost phase or shortly after booster cutoff are goals that grow in importance with the proliferation of weapons of mass destruction. This paper addresses the performance of tracking algorithms for TBMs during boost phase and across the transition to ballistic flight. Three families of tracking algorithms are examined: alpha-beta-gamma trackers, Kalman-based trackers, and the interactive multiple model (IMM) tracker. In addition, a variation on the IMM to include prior knowledge of a booster cutoff parameter is examined. Simulated data is used to compare algorithms. Also, the IMM tracker is run on an actual ballistic missile trajectory. Results indicate that IMM trackers show significant advantage in tracking through the model transition represented by booster cutoff.

Robust object tacking based on self-adaptive search area

NASA Astrophysics Data System (ADS)

Dong, Taihang; Zhong, Sheng

2018-02-01

Discriminative correlation filter (DCF) based trackers have recently achieved excellent performance with great computational efficiency. However, DCF based trackers suffer boundary effects, which result in the unstable performance in challenging situations exhibiting fast motion. In this paper, we propose a novel method to mitigate this side-effect in DCF based trackers. We change the search area according to the prediction of target motion. When the object moves fast, broad search area could alleviate boundary effects and reserve the probability of locating object. When the object moves slowly, narrow search area could prevent effect of useless background information and improve computational efficiency to attain real-time performance. This strategy can impressively soothe boundary effects in situations exhibiting fast motion and motion blur, and it can be used in almost all DCF based trackers. The experiments on OTB benchmark show that the proposed framework improves the performance compared with the baseline trackers.

Sign-tracking predicts increased choice of cocaine over food in rats.

PubMed

Tunstall, Brendan J; Kearns, David N

2015-03-15

The purpose of this study was to determine whether the tendency to sign-track to a food cue was predictive of rats' choice of cocaine over food. First, rats were trained on a procedure where insertion of a retractable lever was paired with food. A sub-group of rats - sign-trackers - primarily approached and contacted the lever, while another sub-group - goal-trackers - approached the site of food delivery. Rats were then trained on a choice task where they could choose between an infusion of cocaine (1.0 mg/kg) and a food pellet (45 mg). Sign-trackers chose cocaine over food significantly more often than did goal-trackers. These results support the incentive-salience theory of addiction and add to a growing number of studies which suggest that sign-trackers may model an addiction-prone phenotype. Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanical stability of the CMS strip tracker measured with a laser alignment system

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

Sirunyan, A. M.; Tumasyan, A.; Adam, W.

Here, the CMS tracker consists of 206 m 2 of silicon strip sensors assembled on carbon fibre composite structures and is designed for operation in the temperature range from –25 to +25°C. The mechanical stability of tracker components during physics operation was monitored with a few μm resolution using a dedicated laser alignment system as well as particle tracks from cosmic rays and hadron-hadron collisions. During the LHC operational period of 2011–2013 at stable temperatures, the components of the tracker were observed to experience relative movements of less than 30μm. In addition, temperature variations were found to cause displacements ofmore » tracker structures of about 2μm°C, which largely revert to their initial positions when the temperature is restored to its original value.« less

Mechanical stability of the CMS strip tracker measured with a laser alignment system

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2017-04-21

Here, the CMS tracker consists of 206 m 2 of silicon strip sensors assembled on carbon fibre composite structures and is designed for operation in the temperature range from –25 to +25°C. The mechanical stability of tracker components during physics operation was monitored with a few μm resolution using a dedicated laser alignment system as well as particle tracks from cosmic rays and hadron-hadron collisions. During the LHC operational period of 2011–2013 at stable temperatures, the components of the tracker were observed to experience relative movements of less than 30μm. In addition, temperature variations were found to cause displacements ofmore » tracker structures of about 2μm°C, which largely revert to their initial positions when the temperature is restored to its original value.« less

Adaptive Neural Star Tracker Calibration for Precision Spacecraft Pointing and Tracking

NASA Technical Reports Server (NTRS)

Bayard, David S.

1996-01-01

The Star Tracker is an essential sensor for precision pointing and tracking in most 3-axis stabilized spacecraft. In the interest (of) improving pointing performance by taking advantage of dramatic increases in flight computer power and memory anticipated over the next decade, this paper investigates the use of a neural net for adaptive in-flight calibration of the Star Tracker.

Improvement of Hungarian Joint Terminal Attack Program

DTIC Science & Technology

2013-06-13

LST Laser Spot Tracker NVG Night Vision Goggle ROMAD Radio Operator Maintainer and Driver ROVER Remotely Operated Video Enhanced Receiver TACP...visual target designation. The other component consists of a laser spot tracker (LST), which identifies targets by tracking laser energy reflecting...capability for every type of night time missions, laser spot tracker for laser spot search missions, remotely operated video enhanced receiver

A survey of current solid state star tracker technology

NASA Astrophysics Data System (ADS)

Armstrong, R. W.; Staley, D. A.

1985-12-01

This paper is a survey of the current state of the art in design of star trackers for spacecraft attitude determination systems. Specific areas discussed are sensor technology, including the current state-of-the-art solid state sensors and techniques of mounting and cooling the sensor, analog image preprocessing electronics performance, and digital processing hardware and software. Three examples of area array solid state star tracker development are presented - ASTROS, developed by the Jet Propulsion Laboratory, the Retroreflector Field Tracker (RFT) by Ball Aerospace, and TRW's MADAN. Finally, a discussion of solid state line arrays explores the possibilities for one-dimensional imagers which offer simplified scan control electronics.

An accuracy measurement method for star trackers based on direct astronomic observation

PubMed Central

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-01-01

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

Exposure Time Optimization for Highly Dynamic Star Trackers

PubMed Central

Wei, Xinguo; Tan, Wei; Li, Jian; Zhang, Guangjun

2014-01-01

Under highly dynamic conditions, the star-spots on the image sensor of a star tracker move across many pixels during the exposure time, which will reduce star detection sensitivity and increase star location errors. However, this kind of effect can be compensated well by setting an appropriate exposure time. This paper focuses on how exposure time affects the star tracker under highly dynamic conditions and how to determine the most appropriate exposure time for this case. Firstly, the effect of exposure time on star detection sensitivity is analyzed by establishing the dynamic star-spot imaging model. Then the star location error is deduced based on the error analysis of the sub-pixel centroiding algorithm. Combining these analyses, the effect of exposure time on attitude accuracy is finally determined. Some simulations are carried out to validate these effects, and the results show that there are different optimal exposure times for different angular velocities of a star tracker with a given configuration. In addition, the results of night sky experiments using a real star tracker agree with the simulation results. The summarized regularities in this paper should prove helpful in the system design and dynamic performance evaluation of the highly dynamic star trackers. PMID:24618776

An accuracy measurement method for star trackers based on direct astronomic observation.

PubMed

Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

2016-03-07

Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers.

Analyzing Virtual Physics Simulations with Tracker

NASA Astrophysics Data System (ADS)

Claessens, Tom

2017-12-01

In the physics teaching community, Tracker is well known as a user-friendly open source video analysis software, authored by Douglas Brown. With this tool, the user can trace markers indicated on a video or on stroboscopic photos and perform kinematic analyses. Tracker also includes a data modeling tool that allows one to fit some theoretical equations of motion onto experimentally obtained data. In the field of particle mechanics, Tracker has been effectively used for learning and teaching about projectile motion, "toss up" and free-fall vertical motion, and to explain the principle of mechanical energy conservation. Also, Tracker has been successfully used in rigid body mechanics to interpret the results of experiments with rolling/slipping cylinders and moving rods. In this work, I propose an original method in which Tracker is used to analyze virtual computer simulations created with a physics-based motion solver, instead of analyzing video recording or stroboscopic photos. This could be an interesting approach to study kinematics and dynamics problems in physics education, in particular when there is no or limited access to physical labs. I demonstrate the working method with a typical (but quite challenging) problem in classical mechanics: a slipping/rolling cylinder on a rough surface.

TE-Tracker: systematic identification of transposition events through whole-genome resequencing.

PubMed

Gilly, Arthur; Etcheverry, Mathilde; Madoui, Mohammed-Amin; Guy, Julie; Quadrana, Leandro; Alberti, Adriana; Martin, Antoine; Heitkam, Tony; Engelen, Stefan; Labadie, Karine; Le Pen, Jeremie; Wincker, Patrick; Colot, Vincent; Aury, Jean-Marc

2014-11-19

Transposable elements (TEs) are DNA sequences that are able to move from their location in the genome by cutting or copying themselves to another locus. As such, they are increasingly recognized as impacting all aspects of genome function. With the dramatic reduction in cost of DNA sequencing, it is now possible to resequence whole genomes in order to systematically characterize novel TE mobilization in a particular individual. However, this task is made difficult by the inherently repetitive nature of TE sequences, which in some eukaryotes compose over half of the genome sequence. Currently, only a few software tools dedicated to the detection of TE mobilization using next-generation-sequencing are described in the literature. They often target specific TEs for which annotation is available, and are only able to identify families of closely related TEs, rather than individual elements. We present TE-Tracker, a general and accurate computational method for the de-novo detection of germ line TE mobilization from re-sequenced genomes, as well as the identification of both their source and destination sequences. We compare our method with the two classes of existing software: specialized TE-detection tools and generic structural variant (SV) detection tools. We show that TE-Tracker, while working independently of any prior annotation, bridges the gap between these two approaches in terms of detection power. Indeed, its positive predictive value (PPV) is comparable to that of dedicated TE software while its sensitivity is typical of a generic SV detection tool. TE-Tracker demonstrates the benefit of adopting an annotation-independent, de novo approach for the detection of TE mobilization events. We use TE-Tracker to provide a comprehensive view of transposition events induced by loss of DNA methylation in Arabidopsis. TE-Tracker is freely available at http://www.genoscope.cns.fr/TE-Tracker . We show that TE-Tracker accurately detects both the source and destination of novel transposition events in re-sequenced genomes. Moreover, TE-Tracker is able to detect all potential donor sequences for a given insertion, and can identify the correct one among them. Furthermore, TE-Tracker produces significantly fewer false positives than common SV detection programs, thus greatly facilitating the detection and analysis of TE mobilization events.

A star tracker insensitive to stray light generated by radiation sources close to the field of view

NASA Astrophysics Data System (ADS)

Romoli, A.; Gambicorti, L.; Simonetti, F.; Zuccaro Marchi, A.

2017-11-01

Aim of this work is to propose an innovative star tracker, practically insensitive to the radiation coming from the sun or from other strong planetary sources out of (but near) the Field of View. These sources need to be stopped in some way. The classical solution to reject the unwanted radiation is to place a shadow (or baffle) before the star tracker objective. The shadow size depends on the Field of View and on the minimum angle subtended by the source (i.e. the sun) with respect to the optical axis of the star tracker. The lower is this angle the larger is the shadow. Requests for star trackers able to work with the sun as close as possible to the Field of View are increasing, due to the need of maximum mission flexibility. The innovation of this proposed star tracker is conceived by using spatial filtering with a concept complementary to that of coronagraph for sun corona observation, allowing to drastically reduce the size of the shadow. It can also work close to antennas and other part of the platform, which, when illuminated by the sun, become secondary sources capable to blind the star tracker. This kind of accommodation offers three main advantages: no cumbersome shadows (baffle), maximum flexibility in terms of mission profile, less platform location constraints. This new star sensor concept, dated 2007, is now patent pending. Galileo Avionica (now Selex Galileo) is the owner of the patent.

Tracker-on-C for cone-beam CT-guided surgery: evaluation of geometric accuracy and clinical applications

NASA Astrophysics Data System (ADS)

Reaungamornrat, S.; Otake, Y.; Uneri, A.; Schafer, S.; Mirota, D. J.; Nithiananthan, S.; Stayman, J. W.; Khanna, A. J.; Reh, D. D.; Gallia, G. L.; Taylor, R. H.; Siewerdsen, J. H.

2012-02-01

Conventional surgical tracking configurations carry a variety of limitations in line-of-sight, geometric accuracy, and mismatch with the surgeon's perspective (for video augmentation). With increasing utilization of mobile C-arms, particularly those allowing cone-beam CT (CBCT), there is opportunity to better integrate surgical trackers at bedside to address such limitations. This paper describes a tracker configuration in which the tracker is mounted directly on the Carm. To maintain registration within a dynamic coordinate system, a reference marker visible across the full C-arm rotation is implemented, and the "Tracker-on-C" configuration is shown to provide improved target registration error (TRE) over a conventional in-room setup - (0.9+/-0.4) mm vs (1.9+/-0.7) mm, respectively. The system also can generate digitally reconstructed radiographs (DRRs) from the perspective of a tracked tool ("x-ray flashlight"), the tracker, or the C-arm ("virtual fluoroscopy"), with geometric accuracy in virtual fluoroscopy of (0.4+/-0.2) mm. Using a video-based tracker, planning data and DRRs can be superimposed on the video scene from a natural perspective over the surgical field, with geometric accuracy (0.8+/-0.3) pixels for planning data overlay and (0.6+/-0.4) pixels for DRR overlay across all C-arm angles. The field-of-view of fluoroscopy or CBCT can also be overlaid on real-time video ("Virtual Field Light") to assist C-arm positioning. The fixed transformation between the x-ray image and tracker facilitated quick, accurate intraoperative registration. The workflow and precision associated with a variety of realistic surgical tasks were significantly improved using the Tracker-on-C - for example, nearly a factor of 2 reduction in time required for C-arm positioning, reduction or elimination of dose in "hunting" for a specific fluoroscopic view, and confident placement of the x-ray FOV on the surgical target. The proposed configuration streamlines the integration of C-arm CBCT with realtime tracking and demonstrated utility in a spectrum of image-guided interventions (e.g., spine surgery) benefiting from improved accuracy, enhanced visualization, and reduced radiation exposure.

A Bit of Fit: Minimalist Intervention in Adolescents Based on a Physical Activity Tracker

PubMed Central

Gaudet, Jeffrey; Gallant, François

2017-01-01

Background Only 5% of Canadian youth meet the recommended 60 minutes of moderate to vigorous physical activity (MVPA) per day, with leisure time being increasingly allocated to technology usage. Direct-to-consumer mHealth devices that promote physical activity, such as wrist-worn physical activity trackers, have features with potential appeal to youth. Objective The primary purpose of this study was to determine whether a minimalist physical activity tracker-based intervention would lead to an increase in physical activity in young adolescents. A secondary aim of this study was to assess change in physical activity across a 7-week intervention, as measured by the tracker. Methods Using a quasi-experimental crossover design, two groups of 23 young adolescents (aged 13-14 years) were randomly assigned to immediate intervention or delayed intervention. The intervention consisted of wearing a Fitbit-Charge-HR physical activity tracker over a 7-week period. Actical accelerometers were used to measure participants’ levels of MVPA before and at the end of intervention periods for each group. Covariates such as age, sex, stage of change for physical activity behavior, and goal commitment were also measured. Results There was an increase in physical activity over the course of the study period, though it was not related to overall physical activity tracker use. An intervention response did, however, occur in a subset of participants. Specifically, exposure to the physical activity tracker was associated with an average daily increase in MVPA by more than 15 minutes (P=.01) among participants who reported being in the action and maintenance stages of behavior change in relation to participation in physical activity. Participants in the precontemplation, contemplation, and preparation stages of behavior change had no change in their level of MVPA (P=.81). Conclusions These results suggest that physical activity trackers may elicit improved physical activity related behavior in young adolescents demonstrating a readiness to be active. Future studies should seek to investigate if integrating physical activity trackers as part of more intensive interventions leads to greater increases in physical activity across different levels of stages of behavior change and if these changes can be sustained over longer periods of time. PMID:28684384

On-Orbit Solar Dynamics Observatory (SDO) Star Tracker Warm Pixel Analysis

NASA Technical Reports Server (NTRS)

Felikson, Denis; Ekinci, Matthew; Hashmall, Joseph A.; Vess, Melissa

2011-01-01

This paper describes the process of identification and analysis of warm pixels in two autonomous star trackers on the Solar Dynamics Observatory (SDO) mission. A brief description of the mission orbit and attitude regimes is discussed and pertinent star tracker hardware specifications are given. Warm pixels are defined and the Quality Index parameter is introduced, which can be explained qualitatively as a manifestation of a possible warm pixel event. A description of the algorithm used to identify warm pixel candidates is given. Finally, analysis of dumps of on-orbit star tracker charge coupled devices (CCD) images is presented and an operational plan going forward is discussed. SDO, launched on February 11, 2010, is operated from the NASA Goddard Space Flight Center (GSFC). SDO is in a geosynchronous orbit with a 28.5 inclination. The nominal mission attitude points the spacecraft X-axis at the Sun, with the spacecraft Z-axis roughly aligned with the Solar North Pole. The spacecraft Y-axis completes the triad. In attitude, SDO moves approximately 0.04 per hour, mostly about the spacecraft Z-axis. The SDO star trackers, manufactured by Galileo Avionica, project the images of stars in their 16.4deg x 16.4deg fields-of-view onto CCD detectors consisting of 512 x 512 pixels. The trackers autonomously identify the star patterns and provide an attitude estimate. Each unit is able to track up to 9 stars. Additionally, each tracker calculates a parameter called the Quality Index, which is a measure of the quality of the attitude solution. Each pixel in the CCD measures the intensity of light and a warns pixel is defined as having a measurement consistently and significantly higher than the mean background intensity level. A warns pixel should also have lower intensity than a pixel containing a star image and will not move across the field of view as the attitude changes (as would a dim star image). It should be noted that the maximum error introduced in the star tracker attitude solution during suspected warm pixel corruptions is within the specified 36 attitude error budget requirement of [35, 70, 70] arcseconds. Thus, the star trackers provided attitude accuracy within the specification for SDO. The star tracker images are intentionally defocused so each star image is detected in more than one CCD pixel. The position of each star is calculated as an intensity-weighted average of the illuminated pixels. The exact method of finding the positions is proprietary to the tracker manufacturer. When a warm pixel happens to be in the vicinity of a star, it can corrupt the calculation of the position of that particular star, thereby corrupting the estimate of the attitude.

User Acceptance of Wrist-Worn Activity Trackers Among Community-Dwelling Older Adults: Mixed Method Study.

PubMed

Puri, Arjun; Kim, Ben; Nguyen, Olivier; Stolee, Paul; Tung, James; Lee, Joon

2017-11-15

Wearable activity trackers are newly emerging technologies with the anticipation for successfully supporting aging-in-place. Consumer-grade wearable activity trackers are increasingly ubiquitous in the market, but the attitudes toward, as well as acceptance and voluntary use of, these trackers in older population are poorly understood. The aim of this study was to assess acceptance and usage of wearable activity trackers in Canadian community-dwelling older adults, using the potentially influential factors as identified in literature and technology acceptance model. A mixed methods design was used. A total of 20 older adults aged 55 years and older were recruited from Southwestern Ontario. Participants used 2 different wearable activity trackers (Xiaomi Mi Band and Microsoft Band) separately for each segment in the crossover design study for 21 days (ie, 42 days total). A questionnaire was developed to capture acceptance and experience at the end of each segment, representing 2 different devices. Semistructured interviews were conducted with 4 participants, and a content analysis was performed. Participants ranged in age from 55 years to 84 years (mean age: 64 years). The Mi Band gained higher levels of acceptance (16/20, 80%) compared with the Microsoft Band (10/20, 50%). The equipment characteristics dimension scored significantly higher for the Mi Band (P<.05). The amount a participant was willing to pay for the device was highly associated with technology acceptance (P<.05). Multivariate logistic regression with 3 covariates resulted in an area under the curve of 0.79. Content analysis resulted in the formation of the following main themes: (1) smartphones as facilitators of wearable activity trackers; (2) privacy is less of a concern for wearable activity trackers, (3) value proposition: self-awareness and motivation; (4) subjective norm, social support, and sense of independence; and (5) equipment characteristics matter: display, battery, comfort, and aesthetics. Older adults were mostly accepting of wearable activity trackers, and they had a clear understanding of its value for their lives. Wearable activity trackers were uniquely considered more personal than other types of technologies, thereby the equipment characteristics including comfort, aesthetics, and price had a significant impact on the acceptance. Results indicated that privacy was less of concern for older adults, but it may have stemmed from a lack of understanding of the privacy risks and implications. These findings add to emerging research that investigates acceptance and factors that may influence acceptance of wearable activity trackers among older adults. ©Arjun Puri, Ben Kim, Olivier Nguyen, Paul Stolee, James Tung, Joon Lee. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 15.11.2017.

ATLAS FTK a - very complex - custom super computer

NASA Astrophysics Data System (ADS)

Kimura, N.; ATLAS Collaboration

2016-10-01

In the LHC environment for high interaction pile-up, advanced techniques of analysing the data in real time are required in order to maximize the rate of physics processes of interest with respect to background processes. The Fast TracKer (FTK) is a track finding implementation at the hardware level that is designed to deliver full-scan tracks with pT above 1 GeV to the ATLAS trigger system for events passing the Level-1 accept (at a maximum rate of 100 kHz). In order to achieve this performance, a highly parallel system was designed and currently it is being commissioned within in ATLAS. Starting in 2016 it will provide tracks for the trigger system in a region covering the central part of the ATLAS detector, and will be extended to the full detector coverage. The system relies on matching hits coming from the silicon tracking detectors against one billion patterns stored in custom ASIC chips (Associative memory chip - AM06). In a first stage, coarse resolution hits are matched against the patterns and the accepted hits undergo track fitting implemented in FPGAs. Tracks with pT > 1GeV are delivered to the High Level Trigger within about 100 ps. Resolution of the tracks coming from FTK is close to the offline tracking and it will allow for reliable detection of primary and secondary vertexes at trigger level and improved trigger performance for b-jets and tau leptons. This contribution will give an overview of the FTK system and present the status of commissioning of the system. Additionally, the expected FTK performance will be briefly described.

Combinations of 148 navigation stars and the star tracker

NASA Technical Reports Server (NTRS)

Duncan, R.

1980-01-01

The angular separation of all star combinations for 148 nav star on the onboard software for space transportation system-3 flight and following missions is presented as well as the separation of each pair that satisfies the viewing constraints of using both star trackers simultaneously. Tables show (1) shuttle star catalog 1980 star position in M 1950 coordinates; (2) two star combination of 148 nav stars; and (3) summary of two star-combinations of the star tracker 5 deg filter. These 148 stars present 10,875 combinations. For the star tracker filters of plus or minus 5 deg, there are 875 combinations. Formalhaut (nav star 26) has the best number of combinations, which is 33.

Robust Visual Tracking Revisited: From Correlation Filter to Template Matching.

PubMed

Liu, Fanghui; Gong, Chen; Huang, Xiaolin; Zhou, Tao; Yang, Jie; Tao, Dacheng

2018-06-01

In this paper, we propose a novel matching based tracker by investigating the relationship between template matching and the recent popular correlation filter based trackers (CFTs). Compared to the correlation operation in CFTs, a sophisticated similarity metric termed mutual buddies similarity is proposed to exploit the relationship of multiple reciprocal nearest neighbors for target matching. By doing so, our tracker obtains powerful discriminative ability on distinguishing target and background as demonstrated by both empirical and theoretical analyses. Besides, instead of utilizing single template with the improper updating scheme in CFTs, we design a novel online template updating strategy named memory, which aims to select a certain amount of representative and reliable tracking results in history to construct the current stable and expressive template set. This scheme is beneficial for the proposed tracker to comprehensively understand the target appearance variations, recall some stable results. Both qualitative and quantitative evaluations on two benchmarks suggest that the proposed tracking method performs favorably against some recently developed CFTs and other competitive trackers.

Chemoreception of hunger levels alters the following behaviour of a freshwater snail.

PubMed

Larcher, Marie; Crane, Adam L

2015-12-01

Chemically-mediated orientation is essential for many animals that must locate sites containing resources such as mates or food. One way to find these areas is by using publically-available information from other individuals. We tested a freshwater snail, Physa gyrina, for chemoreception of conspecific cues and predicted they could discriminate between cues based on information regarding hunger levels. We placed 'tracker' snails into a 2-arm arena where they could either follow or avoid an area previously used by a 'marker' snail. The hunger levels of both trackers and markers was manipulated, being either starved or fed. Starved and fed trackers did not differ in their following response when markers were hungry, but starved trackers were significantly more likely to follow fed markers, compared to fed trackers that tended to avoid areas used by fed markers. This outcome suggests that P. gyrina uses conspecific chemical cues to find food and potentially in some situations to avoid intra-specific food competition. Copyright © 2015 Elsevier B.V. All rights reserved.

Star tracker operation in a high density proton field

NASA Technical Reports Server (NTRS)

Miklus, Kenneth J.; Kissh, Frank; Flynn, David J.

1993-01-01

Algorithms that reject transient signals due to proton effects on charge coupled device (CCD) sensors have been implemented in the HDOS ASTRA-l Star Trackers to be flown on the TOPEX mission scheduled for launch in July 1992. A unique technique for simulating a proton-rich environment to test trackers is described, as well as the test results obtained. Solar flares or an orbit that passes through the South Atlantic Anomaly can subject the vehicle to very high proton flux levels. There are three ways in which spurious proton generated signals can impact tracker performance: the many false signals can prevent or extend the time to acquire a star; a proton-generated signal can compromise the accuracy of the star's reported magnitude and position; and the tracked star can be lost, requiring reacquisition. Tests simulating a proton-rich environment were performed on two ASTRA-1 Star Trackers utilizing these new algorithms. There were no false acquisitions, no lost stars, and a significant reduction in reported position errors due to these improvements.

Method of producing strained-layer semiconductor devices via subsurface-patterning

DOEpatents

Dodson, Brian W.

1993-01-01

A method is described for patterning subsurface features in a semiconductor device, wherein the semiconductor device includes an internal strained layer. The method comprises creating a pattern of semiconductor material over the semiconductor device, the semiconductor material having a predetermined thickness which stabilizes areas of the strained semiconductor layer that lie beneath the pattern. Subsequently, a heating step is applied to the semiconductor device to cause a relaxation in areas of the strained layer which do not lie beneath the semiconductor material pattern, whereby dislocations result in the relaxed areas and impair electrical transport therethrough.

Coupling and decoupling of the accelerating units for pulsed synchronous linear accelerator

NASA Astrophysics Data System (ADS)

Shen, Yi; Liu, Yi; Ye, Mao; Zhang, Huang; Wang, Wei; Xia, Liansheng; Wang, Zhiwen; Yang, Chao; Shi, Jinshui; Zhang, Linwen; Deng, Jianjun

2017-12-01

A pulsed synchronous linear accelerator (PSLA), based on the solid-state pulse forming line, photoconductive semiconductor switch, and high gradient insulator technologies, is a novel linear accelerator. During the prototype PSLA commissioning, the energy gain of proton beams was found to be much lower than expected. In this paper, the degradation of the energy gain is explained by the circuit and cavity coupling effect of the accelerating units. The coupling effects of accelerating units are studied, and the circuit topologies of these two kinds of coupling effects are presented. Two methods utilizing inductance and membrane isolations, respectively, are proposed to reduce the circuit coupling effects. The effectiveness of the membrane isolation method is also supported by simulations. The decoupling efficiency of the metal drift tube is also researched. We carried out the experiments on circuit decoupling of the multiple accelerating cavity. The result shows that both circuit decoupling methods could increase the normalized voltage.

Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

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

Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Shvyd’ko, Yuri; Trakhtenberg, Emil

2016-07-27

We report progress on implementation and commissioning of sequential X-ray diffraction topography at 1-BM Optics Testing Beamline of the Advanced Photon Source to accommodate growing needs of strain characterization in diffractive crystal optics and other semiconductor single crystals. The setup enables evaluation of strain in single crystals in the nearly-nondispersive double-crystal geometry. Si asymmetric collimator crystals of different crystallographic orientations were designed, fabricated and characterized using in-house capabilities. Imaging the exit beam using digital area detectors permits rapid sequential acquisition of X-ray topographs at different angular positions on the rocking curve of a crystal under investigation. Results on sensitivity andmore » spatial resolution are reported based on experiments with high-quality Si and diamond crystals. The new setup complements laboratory-based X-ray topography capabilities of the Optics group at the Advanced Photon Source.« less

Utilizing Maximum Power Point Trackers in Parallel to Maximize the Power Output of a Solar (Photovoltaic) Array

DTIC Science & Technology

2012-12-01

photovoltaic (PV) system to use a maximum power point tracker ( MPPT ) to increase... photovoltaic (PV) system to use a maximum power point tracker ( MPPT ) to increase the power output of the solar array. Currently, most military... MPPT ) is an optimizing circuit that is used in conjunction with photovoltaic (PV) arrays to achieve the maximum delivery of power from the array

A Methodology to Analyze Photovoltaic Tracker Uptime

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

Muller, Matthew T; Ruth, Dan

A metric is developed to analyze the daily performance of single-axis photovoltaic (PV) trackers. The metric relies on comparing correlations between the daily time series of the PV power output and an array of simulated plane-of-array irradiances for the given day. Mathematical thresholds and a logic sequence are presented, so the daily tracking metric can be applied in an automated fashion on large-scale PV systems. The results of applying the metric are visually examined against the time series of the power output data for a large number of days and for various systems. The visual inspection results suggest that overall,more » the algorithm is accurate in identifying stuck or functioning trackers on clear-sky days. Visual inspection also shows that there are days that are not classified by the metric where the power output data may be sufficient to identify a stuck tracker. Based on the daily tracking metric, uptime results are calculated for 83 different inverters at 34 PV sites. The mean tracker uptime is calculated at 99% based on 2 different calculation methods. The daily tracking metric clearly has limitations, but as there is no existing metrics in the literature, it provides a valuable tool for flagging stuck trackers.« less

Use of a Remote Eye-Tracker for the Analysis of Gaze during Treadmill Walking and Visual Stimuli Exposition.

PubMed

Serchi, V; Peruzzi, A; Cereatti, A; Della Croce, U

2016-01-01

The knowledge of the visual strategies adopted while walking in cognitively engaging environments is extremely valuable. Analyzing gaze when a treadmill and a virtual reality environment are used as motor rehabilitation tools is therefore critical. Being completely unobtrusive, remote eye-trackers are the most appropriate way to measure the point of gaze. Still, the point of gaze measurements are affected by experimental conditions such as head range of motion and visual stimuli. This study assesses the usability limits and measurement reliability of a remote eye-tracker during treadmill walking while visual stimuli are projected. During treadmill walking, the head remained within the remote eye-tracker workspace. Generally, the quality of the point of gaze measurements declined as the distance from the remote eye-tracker increased and data loss occurred for large gaze angles. The stimulus location (a dot-target) did not influence the point of gaze accuracy, precision, and trackability during both standing and walking. Similar results were obtained when the dot-target was replaced by a static or moving 2D target and "region of interest" analysis was applied. These findings foster the feasibility of the use of a remote eye-tracker for the analysis of gaze during treadmill walking in virtual reality environments.

Contradictions in digital health engagement: An activity tracker's ambiguous influence on vulnerable young adults' engagement in own health.

PubMed

Kanstrup, Anne Marie; Bertelsen, Pernille; Jensen, Martin B

2018-01-01

Activity trackers are designed to support individuals in monitoring and increasing their physical activity. The use of activity trackers among individuals diagnosed with depression and anxiety has not yet been examined. This pilot study investigates how this target group engages with an activity tracker during a 10-week health intervention aimed to increase their physical activity level and improve their physical and mental health. Two groups of 11 young adults (aged 18-29 years) diagnosed with depression or anxiety participated in the digital health intervention. The study used mixed methods to investigate the research question. Quantitative health data were used to assess the intervention's influence on the participants' health and qualitative data provided insights into the participants' digital health experience. The study demonstrated an ambiguous influence from the use of an activity tracker with positive physical and mental health results, but a fading and even negative digital health engagement and counterproductive competition. The ambiguous results identify a need for (1) developing strategies for health professionals to provide supervised use of activity trackers and support the target groups' abilities to convert health information about physical activity into positive health strategies, and (2) designing alternatives for health promoting IT targeted users who face challenges and need motivation beyond self-tracking and competition.

Star Tracker Performance Estimate with IMU

NASA Technical Reports Server (NTRS)

Aretskin-Hariton, Eliot D.; Swank, Aaron J.

2015-01-01

A software tool for estimating cross-boresight error of a star tracker combined with an inertial measurement unit (IMU) was developed to support trade studies for the Integrated Radio and Optical Communication project (iROC) at the National Aeronautics and Space Administration Glenn Research Center. Typical laser communication systems, such as the Lunar Laser Communication Demonstration (LLCD) and the Laser Communication Relay Demonstration (LCRD), use a beacon to locate ground stations. iROC is investigating the use of beaconless precision laser pointing to enable laser communication at Mars orbits and beyond. Precision attitude knowledge is essential to the iROC mission to enable high-speed steering of the optical link. The preliminary concept to achieve this precision attitude knowledge is to use star trackers combined with an IMU. The Star Tracker Accuracy (STAcc) software was developed to rapidly assess the capabilities of star tracker and IMU configurations. STAcc determines the overall cross-boresight error of a star tracker with an IMU given the characteristic parameters: quantum efficiency, aperture, apparent star magnitude, exposure time, field of view, photon spread, detector pixels, spacecraft slew rate, maximum stars used for quaternion estimation, and IMU angular random walk. This paper discusses the supporting theory used to construct STAcc, verification of the program and sample results.

Tracker-assisted versus manual ablation zone centration in laser in situ keratomileusis for myopia and astigmatism.

PubMed

Pineros, Oscar E

2002-01-01

Eye tracker systems have been developed concomitantly with small scanning beams to theoretically reduce ablation zone decentration and for accurate registration of all the laser pulses on the cornea. The purpose of the study was to compare the tracker-assisted with the manual centration method. Twenty-five patients (48 eyes) with myopia and/or astigmatism had laser in situ keratomileusis (LASIK) between August 1998 and February 1999 with the Technolas 117C laser. Twenty patients (38 eyes, 80%) were available for follow-up at 3 months after surgery. Eyes were assigned randomly to one of two ablation zone centration methods: Group 1: Tracker-assisted (20 eyes), Group 2: Manual (18 eyes). Mean distance between the ablation zone center and the pupillary center in the tracker-assisted centration group was 0.55 +/- 0.30 mm (range, 0.10 to 1.4 mm), and in the manual centration group, 0.43 +/- 0.23 mm (range, 0.10 to 1.0 mm) (P = .177). There was no statistically significant difference in postoperative contrast sensitivity, glare, and Topographical Corneal Surface Regularity Index (SRI) between the two groups. We obtained good results with both centration methods. We did not find superiority of the tracker-assisted over manual regarding ablation zone centration, vision quality, or regularity of the ablation.

75 FR 49526 - Freescale Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-13

... Semiconductor, Inc., Technical Information Center, Tempe, AZ; Freescale Semiconductor, Inc., Technical... October 1, 2009, applicable to workers of Freescale Semiconductor, Inc., Technical Information Center..., Massachusetts location of Freescale Semiconductor, Inc., Technical Information Center. The intent of the...

Using CarbonTracker carbon flux estimates to improve a terrestrial carbon cycle model

NASA Astrophysics Data System (ADS)

Peters, W.; Krol, M.; Miller, J. B.; Tans, P. P.; Carvalhais, N.; Schaefer, K.

2009-12-01

Estimates of net ecosystem exchange (NEE) from NOAA’s CarbonTracker CO2 data assimilation system show patterns of annual net uptake not represented in most terrestrial carbon cycle models. This is mainly because such models lack information on the land-use history of individual ecosystems, which is the main driver of long-term mean carbon exchange. Instead, they assume the biosphere to be in steady-state, with annual gross photosynthesis equalling ecosystem respiration everywhere. This limits their use in interpreting observations of carbon dynamics such as with eddy-covariance techniques or through atmospheric CO2 records. We have implemented a method that takes the long-term mean NEE estimates from CarbonTracker to derive the size of the dominant carbon pool in each ecosystem of the SIBCASA biosphere model. With the new pool sizes, the SIBCASA model is no longer in steady-state and reproduces annual carbon uptake patterns from CarbonTracker. We will show that the non steady-state SIBCASA model is not only much more consistent with the atmospheric CO2 record, but also with independent data on standing wood biomass and forest age from the Forest Inventory and Analysis (FIA) Program of the U.S. Forest Service. Four years of CarbonTracker NEE are needed to reliably derive a long term mean for this process, and we use three other years from CarbonTracker to evaluate the non steady state SIBCASA NEE. We will furthermore show that the non steady-state SIBCASA NEE is a much better first-guess for the CarbonTracker data assimilation process, allowing more confidence in its final NEE estimate, and reducing a systematic bias in CarbonTracker modeled atmospheric CO2. This overcomes a long standing issue in inverse modeling, and opens the way for further assessment and improvement of carbon cycle models such as SIBCASA.

Youth Oriented Activity Trackers: Comprehensive Laboratory- and Field-Based Validation

PubMed Central

2017-01-01

Background Commercial activity trackers are growing in popularity among adults and some are beginning to be marketed to children. There is, however, a paucity of independent research examining the validity of these devices to detect physical activity of different intensity levels. Objectives The purpose of this study was to determine the validity of the output from 3 commercial youth-oriented activity trackers in 3 phases: (1) orbital shaker, (2) structured indoor activities, and (3) 4 days of free-living activity. Methods Four units of each activity tracker (Movband [MB], Sqord [SQ], and Zamzee [ZZ]) were tested in an orbital shaker for 5-minutes at three frequencies (1.3, 1.9, and 2.5 Hz). Participants for Phase 2 (N=14) and Phase 3 (N=16) were 6-12 year old children (50% male). For Phase 2, participants completed 9 structured activities while wearing each tracker, the ActiGraph GT3X+ (AG) research accelerometer, and a portable indirect calorimetry system to assess energy expenditure (EE). For Phase 3, participants wore all 4 devices for 4 consecutive days. Correlation coefficients, linear models, and non-parametric statistics evaluated the criterion and construct validity of the activity tracker output. Results Output from all devices was significantly associated with oscillation frequency (r=.92-.99). During Phase 2, MB and ZZ only differentiated sedentary from light intensity (P<.01), whereas the SQ significantly differentiated among all intensity categories (all comparisons P<.01), similar to AG and EE. During Phase 3, AG counts were significantly associated with activity tracker output (r=.76, .86, and .59 for the MB, SQ, and ZZ, respectively). Conclusions Across study phases, the SQ demonstrated stronger validity than the MB and ZZ. The validity of youth-oriented activity trackers may directly impact their effectiveness as behavior modification tools, demonstrating a need for more research on such devices. PMID:28724509

Optically switched graphene/4H-SiC junction bipolar transistor

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

Chandrashekhar, MVS; Sudarshan, Tangali S.; Omar, Sabih U.

A bi-polar device is provided, along with methods of making the same. The bi-polar device can include a semiconductor substrate doped with a first dopant, a semiconductor layer on the first surface of the semiconductor substrate, and a Schottky barrier layer on the semiconductor layer. The method of forming a bi-polar device can include: forming a semiconductor layer on a first surface of a semiconductor substrate, where the semiconductor substrate comprises a first dopant and where the semiconductor layer comprises a second dopant that has an opposite polarity than the first dopant; and forming a Schottky barrier layer on amore » first portion of the semiconductor layer while leaving a second portion of the semiconductor layer exposed.« less

Methods of producing free-standing semiconductors using sacrificial buffer layers and recyclable substrates

DOEpatents

Ptak, Aaron Joseph; Lin, Yong; Norman, Andrew; Alberi, Kirstin

2015-05-26

A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a spinel substrate using a sacrificial buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The sacrificial buffer material and semiconductor materials may be deposited using lattice-matching epitaxy or coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The sacrificial buffer layer may be dissolved using an epitaxial liftoff technique in order to separate the semiconductor device from the spinel substrate, and the spinel substrate may be reused in the subsequent fabrication of other semiconductor devices. The low-defect density semiconductor materials produced using this method result in the enhanced performance of the semiconductor devices that incorporate the semiconductor materials.

Patterns of Fitbit Use and Activity Levels Throughout a Physical Activity Intervention: Exploratory Analysis from a Randomized Controlled Trial

PubMed Central

Nelson, Sandahl H; Weiner, Lauren S

2018-01-01

Background There has been a rapid increase in the use of technology-based activity trackers to promote behavior change. However, little is known about how individuals use these trackers on a day-to-day basis or how tracker use relates to increasing physical activity. Objective The aims were to use minute level data collected from a Fitbit tracker throughout a physical activity intervention to examine patterns of Fitbit use and activity and their relationships with success in the intervention based on ActiGraph-measured moderate to vigorous physical activity (MVPA). Methods Participants included 42 female breast cancer survivors randomized to the physical activity intervention arm of a 12-week randomized controlled trial. The Fitbit One was worn daily throughout the 12-week intervention. ActiGraph GT3X+ accelerometer was worn for 7 days at baseline (prerandomization) and end of intervention (week 12). Self-reported frequency of looking at activity data on the Fitbit tracker and app or website was collected at week 12. Results Adherence to wearing the Fitbit was high and stable, with a mean of 88.13% of valid days over 12 weeks (SD 14.49%). Greater adherence to wearing the Fitbit was associated with greater increases in ActiGraph-measured MVPA (binteraction=0.35, P<.001). Participants averaged 182.6 minutes/week (SD 143.9) of MVPA on the Fitbit, with significant variation in MVPA over the 12 weeks (F=1.91, P=.04). The majority (68%, 27/40) of participants reported looking at their tracker or looking at the Fitbit app or website once a day or more. Changes in Actigraph-measured MVPA were associated with frequency of looking at one’s data on the tracker (b=−1.36, P=.07) but not significantly associated with frequency of looking at one’s data on the app or website (P=.36). Conclusions This is one of the first studies to explore the relationship between use of a commercially available activity tracker and success in a physical activity intervention. A deeper understanding of how individuals engage with technology-based trackers may enable us to more effectively use these types of trackers to promote behavior change. Trial Registration ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876?term=NCT02332876 &rank=1 (Archived by WebCite at http://www.webcitation.org/6wplEeg8i). PMID:29402761

Patterns of Fitbit Use and Activity Levels Throughout a Physical Activity Intervention: Exploratory Analysis from a Randomized Controlled Trial.

PubMed

Hartman, Sheri J; Nelson, Sandahl H; Weiner, Lauren S

2018-02-05

There has been a rapid increase in the use of technology-based activity trackers to promote behavior change. However, little is known about how individuals use these trackers on a day-to-day basis or how tracker use relates to increasing physical activity. The aims were to use minute level data collected from a Fitbit tracker throughout a physical activity intervention to examine patterns of Fitbit use and activity and their relationships with success in the intervention based on ActiGraph-measured moderate to vigorous physical activity (MVPA). Participants included 42 female breast cancer survivors randomized to the physical activity intervention arm of a 12-week randomized controlled trial. The Fitbit One was worn daily throughout the 12-week intervention. ActiGraph GT3X+ accelerometer was worn for 7 days at baseline (prerandomization) and end of intervention (week 12). Self-reported frequency of looking at activity data on the Fitbit tracker and app or website was collected at week 12. Adherence to wearing the Fitbit was high and stable, with a mean of 88.13% of valid days over 12 weeks (SD 14.49%). Greater adherence to wearing the Fitbit was associated with greater increases in ActiGraph-measured MVPA (b interaction =0.35, P<.001). Participants averaged 182.6 minutes/week (SD 143.9) of MVPA on the Fitbit, with significant variation in MVPA over the 12 weeks (F=1.91, P=.04). The majority (68%, 27/40) of participants reported looking at their tracker or looking at the Fitbit app or website once a day or more. Changes in Actigraph-measured MVPA were associated with frequency of looking at one's data on the tracker (b=-1.36, P=.07) but not significantly associated with frequency of looking at one's data on the app or website (P=.36). This is one of the first studies to explore the relationship between use of a commercially available activity tracker and success in a physical activity intervention. A deeper understanding of how individuals engage with technology-based trackers may enable us to more effectively use these types of trackers to promote behavior change. ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876?term=NCT02332876 &rank=1 (Archived by WebCite at http://www.webcitation.org/6wplEeg8i). ©Sheri J Hartman, Sandahl H Nelson, Lauren S Weiner. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 05.02.2018.

Tracking Detectors in the STAR Experiment at RHIC

NASA Astrophysics Data System (ADS)

Wieman, Howard

2015-04-01

The STAR experiment at RHIC is designed to measure and identify the thousands of particles produced in 200 Gev/nucleon Au on Au collisions. This talk will focus on the design and construction of two of the main tracking detectors in the experiment, the TPC and the Heavy Flavor Tracker (HFT) pixel detector. The TPC is a solenoidal gas filled detector 4 meters in diameter and 4.2 meters long. It provides precise, continuous tracking and rate of energy loss in the gas (dE/dx) for particles at + - 1 units of pseudo rapidity. The tracking in a half Tesla magnetic field measures momentum and dE/dX provides particle ID. To detect short lived particles tracking close to the point of interaction is required. The HFT pixel detector is a two-layered, high resolution vertex detector located at a few centimeters radius from the collision point. It determines origins of the tracks to a few tens of microns for the purpose of extracting displaced vertices, allowing the identification of D mesons and other short-lived particles. The HFT pixel detector uses detector chips developed by the IPHC group at Strasbourg that are based on standard IC Complementary Metal-Oxide-Semiconductor (CMOS) technology. This is the first time that CMOS pixel chips have been incorporated in a collider application.

Electric field induced spin-polarized current

DOEpatents

Murakami, Shuichi; Nagaosa, Naoto; Zhang, Shoucheng

2006-05-02

A device and a method for generating an electric-field-induced spin current are disclosed. A highly spin-polarized electric current is generated using a semiconductor structure and an applied electric field across the semiconductor structure. The semiconductor structure can be a hole-doped semiconductor having finite or zero bandgap or an undoped semiconductor of zero bandgap. In one embodiment, a device for injecting spin-polarized current into a current output terminal includes a semiconductor structure including first and second electrodes, along a first axis, receiving an applied electric field and a third electrode, along a direction perpendicular to the first axis, providing the spin-polarized current. The semiconductor structure includes a semiconductor material whose spin orbit coupling energy is greater than room temperature (300 Kelvin) times the Boltzmann constant. In one embodiment, the semiconductor structure is a hole-doped semiconductor structure, such as a p-type GaAs semiconductor layer.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, David R.

1995-01-01

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays From the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detect or such that each one of the of semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction.

High resolution energy-sensitive digital X-ray

DOEpatents

Nygren, D.R.

1995-07-18

An apparatus and method for detecting an x-ray and for determining the depth of penetration of an x-ray into a semiconductor strip detector. In one embodiment, a semiconductor strip detector formed of semiconductor material is disposed in an edge-on orientation towards an x-ray source such that x-rays from the x-ray source are incident upon and substantially perpendicular to the front edge of the semiconductor strip detector. The semiconductor strip detector is formed of a plurality of segments. The segments are coupled together in a collinear arrangement such that the semiconductor strip detector has a length great enough such that substantially all of the x-rays incident on the front edge of the semiconductor strip detector interact with the semiconductor material which forms the semiconductor strip detector. A plurality of electrodes are connected to the semiconductor strip detector such that each one of the semiconductor strip detector segments has at least one of the of electrodes coupled thereto. A signal processor is also coupled to each one of the electrodes. The present detector detects an interaction within the semiconductor strip detector, between an x-ray and the semiconductor material, and also indicates the depth of penetration of the x-ray into the semiconductor strip detector at the time of the interaction. 5 figs.

Breadboard stellar tracker system test report, volume 2

NASA Technical Reports Server (NTRS)

1981-01-01

Complete data from a test program designed to evaluate the performance of a star tracker, a breadboard tracker system, is presented in tabular form. All data presented was normalized to the pixel dimension of 20 micrometers. Data from determination of maximum spatial noise as it applies to the coarse and fine acquisition modes is presented. Pointing accuracy test data, raw pixel data for the track cycle, and data from equipment related tests is also presented.

S-band range tracker and Surveillance Lab interface

NASA Astrophysics Data System (ADS)

Bush, B. D.

1983-09-01

This report documents the design, construction, test and laboratory integration of the range tracker and associated subsystems for the RADC/OC Surveillance Laboratory's S-Band tracking radar. This development was accomplished over the period from December 1981 to November 1983 and was designed, constructed and tested entirely in-house. This report contains information on the use of the range tracker, its interfaces to other laboratory equipment, the philosophy behind its design, the detailed design of the hardware (including schematics, timing and cabling diagrams), the detailed software design (including flowcharts), and the mathematical description of its algorithms. The range tracker will be used in conjunction with other equipment in the OC Surveillance Lab in the taking and recording of radar data during flight tests.

Reduction of low frequency error for SED36 and APS based HYDRA star trackers

NASA Astrophysics Data System (ADS)

Ouaknine, Julien; Blarre, Ludovic; Oddos-Marcel, Lionel; Montel, Johan; Julio, Jean-Marc

2017-11-01

In the frame of the CNES Pleiades satellite, a reduction of the star tracker low frequency error, which is the most penalizing error for the satellite attitude control, was performed. For that purpose, the SED36 star tracker was developed, with a design based on the flight qualified SED16/26. In this paper, the SED36 main features will be first presented. Then, the reduction process of the low frequency error will be developed, particularly the optimization of the optical distortion calibration. The result is an attitude low frequency error of 1.1" at 3 sigma along transverse axes. The implementation of these improvements to HYDRA, the new multi-head APS star tracker developed by SODERN, will finally be presented.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon [Pinole, CA; Bruchez, Jr., Marcel; Alivisatos, Paul [Oakland, CA

2008-01-01

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) an affinity molecule linked to the semiconductor nanocrystal. The semiconductor nanocrystal is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Exposure of the semiconductor nanocrystal to excitation energy will excite the semiconductor nanocrystal causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

tkLayout: a design tool for innovative silicon tracking detectors

NASA Astrophysics Data System (ADS)

Bianchi, G.

2014-03-01

A new CMS tracker is scheduled to become operational for the LHC Phase 2 upgrade in the early 2020's. tkLayout is a software package developed to create 3d models for the design of the CMS tracker and to evaluate its fundamental performance figures. The new tracker will have to cope with much higher luminosity conditions, resulting in increased track density, harsher radiation exposure and, especially, much higher data acquisition bandwidth, such that equipping the tracker with triggering capabilities is envisaged. The design of an innovative detector involves deciding on an architecture offering the best trade-off among many figures of merit, such as tracking resolution, power dissipation, bandwidth, cost and so on. Quantitatively evaluating these figures of merit as early as possible in the design phase is of capital importance and it is best done with the aid of software models. tkLayout is a flexible modeling tool: new performance estimates and support for different detector geometries can be quickly added, thanks to its modular structure. Besides, the software executes very quickly (about two minutes), so that many possible architectural variations can be rapidly modeled and compared, to help in the choice of a viable detector layout and then to optimize it. A tracker geometry is generated from simple configuration files, defining the module types, layout and materials. Support structures are automatically added and services routed to provide a realistic tracker description. The tracker geometries thus generated can be exported to the standard CMS simulation framework (CMSSW) for full Monte Carlo studies. tkLayout has proven essential in giving guidance to CMS in studying different detector layouts and exploring the feasibility of innovative solutions for tracking detectors, in terms of design, performance and projected costs. This tool has been one of the keys to making important design decisions for over five years now and has also enabled project engineers and simulation experts to focus their efforts on other important or specific issues. Even if tkLayout was designed for the CMS tracker upgrade project, its flexibility makes it experiment-agnostic, so that it could be easily adapted to model other tracking detectors. The technology behind tkLayout is presented, as well as some of the results obtained in the context of the CMS silicon tracker design studies.

A Bit of Fit: Minimalist Intervention in Adolescents Based on a Physical Activity Tracker.

PubMed

Gaudet, Jeffrey; Gallant, François; Bélanger, Mathieu

2017-07-06

Only 5% of Canadian youth meet the recommended 60 minutes of moderate to vigorous physical activity (MVPA) per day, with leisure time being increasingly allocated to technology usage. Direct-to-consumer mHealth devices that promote physical activity, such as wrist-worn physical activity trackers, have features with potential appeal to youth. The primary purpose of this study was to determine whether a minimalist physical activity tracker-based intervention would lead to an increase in physical activity in young adolescents. A secondary aim of this study was to assess change in physical activity across a 7-week intervention, as measured by the tracker. Using a quasi-experimental crossover design, two groups of 23 young adolescents (aged 13-14 years) were randomly assigned to immediate intervention or delayed intervention. The intervention consisted of wearing a Fitbit-Charge-HR physical activity tracker over a 7-week period. Actical accelerometers were used to measure participants' levels of MVPA before and at the end of intervention periods for each group. Covariates such as age, sex, stage of change for physical activity behavior, and goal commitment were also measured. There was an increase in physical activity over the course of the study period, though it was not related to overall physical activity tracker use. An intervention response did, however, occur in a subset of participants. Specifically, exposure to the physical activity tracker was associated with an average daily increase in MVPA by more than 15 minutes (P=.01) among participants who reported being in the action and maintenance stages of behavior change in relation to participation in physical activity. Participants in the precontemplation, contemplation, and preparation stages of behavior change had no change in their level of MVPA (P=.81). These results suggest that physical activity trackers may elicit improved physical activity related behavior in young adolescents demonstrating a readiness to be active. Future studies should seek to investigate if integrating physical activity trackers as part of more intensive interventions leads to greater increases in physical activity across different levels of stages of behavior change and if these changes can be sustained over longer periods of time. ©Jeffrey Gaudet, François Gallant, Mathieu Bélanger. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 06.07.2017.

Healthy Weight

MedlinePlus

... certain health conditions External Resources Weight loss, weight management, nutrition, meal planning tools… Super Tracker SuperTracker: My Plan Food Diary [PDF – 34KB] Physical Activity Diary [PDF – 52KB] ...

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

Cibinetto, G.

Inner Trackers (IT) are key detectors in Particle Physics experiments; excellent spatial resolution, radiation transparency and hardness, and operability under high occupancies are main requirements. We aim to design, build and commission by 2017 a Cylindrical GEM (CGEM) detector candidate to be the new IT of the BESIII spectrometer, hosted on BEPC2 in IHEP, Beijing; BESIII data taking will last until at least 2020. The IT itself will represent an evolution w.r.t. the state of the art of GEM detectors, since the use of new kind of mechanical supports for the GEM foils will reduce the total radiation length ofmore » the detector and improve its tracking performance; an innovative design of the CGEM anode will allow for smaller capacitance and hence for bigger signals. The relatively strong BESIII magnetic field requires a new analogue readout; full custom front-end electronics, including a dedicated ASIC, will be designed and produced for optimal data collection. Prototype Beam Test results showing the measurement of the spatial resolution in a 1 Tesla magnetic field will be presented among with the mechanical design and simulations. (authors)« less

Harmonization of forest disturbance datasets of the conterminous USA from 1986 to 2011

USGS Publications Warehouse

Soulard, Christopher E.; Acevedo, William; Cohen, Warren B.; Yang, Zhiqiang; Stehman, Stephen V.; Taylor, Janis L.

2017-01-01

Several spatial forest disturbance datasets exist for the conterminous USA. The major problem with forest disturbance mapping is that variability between map products leads to uncertainty regarding the actual rate of disturbance. In this article, harmonized maps were produced from multiple data sources (i.e., Global Forest Change, LANDFIRE Vegetation Disturbance, National Land Cover Database, Vegetation Change Tracker, and Web-Enabled Landsat Data). The harmonization process involved fitting common class ontologies and determining spatial congruency to produce forest disturbance maps for four time intervals (1986–1992, 1992–2001, 2001–2006, and 2006–2011). Pixels mapped as disturbed for two or more datasets were labeled as disturbed in the harmonized maps. The primary advantage gained by harmonization was improvement in commission error rates relative to the individual disturbance products. Disturbance omission errors were high for both harmonized and individual forest disturbance maps due to underlying limitations in mapping subtle disturbances with Landsat classification algorithms. To enhance the value of the harmonized disturbance products, we used fire perimeter maps to add information on the cause of disturbance.

Harmonization of forest disturbance datasets of the conterminous USA from 1986 to 2011.

PubMed

Soulard, Christopher E; Acevedo, William; Cohen, Warren B; Yang, Zhiqiang; Stehman, Stephen V; Taylor, Janis L

2017-04-01

Several spatial forest disturbance datasets exist for the conterminous USA. The major problem with forest disturbance mapping is that variability between map products leads to uncertainty regarding the actual rate of disturbance. In this article, harmonized maps were produced from multiple data sources (i.e., Global Forest Change, LANDFIRE Vegetation Disturbance, National Land Cover Database, Vegetation Change Tracker, and Web-Enabled Landsat Data). The harmonization process involved fitting common class ontologies and determining spatial congruency to produce forest disturbance maps for four time intervals (1986-1992, 1992-2001, 2001-2006, and 2006-2011). Pixels mapped as disturbed for two or more datasets were labeled as disturbed in the harmonized maps. The primary advantage gained by harmonization was improvement in commission error rates relative to the individual disturbance products. Disturbance omission errors were high for both harmonized and individual forest disturbance maps due to underlying limitations in mapping subtle disturbances with Landsat classification algorithms. To enhance the value of the harmonized disturbance products, we used fire perimeter maps to add information on the cause of disturbance.

First GRB detections with the AGILE Minicalorimeter

NASA Astrophysics Data System (ADS)

Marisaldi, M.; Labanti, C.; Fuschino, F.; Galli, M.; Tavani, M.; Bulgarelli, A.; Gianotti, F.; Trifoglio, M.; Argan, A.

2008-05-01

The Minicalorimeter (MCAL) onboard the AGILE satellite is a 1400 cm2 scintillation detector sensitive in the energy range 0.3-200 MeV. MCAL works both as a slave of the AGILE Silicon Tracker and as an autonomous detector for transient events (BURST mode). A dedicated onboard Burst Search logic scans BURST mode data in search of count rate increase. Peculiar characteristics of the detector are the high energy spectral coverage and a timing resolution of about 2 microseconds. Even if a trigger is not issued, BURST mode data are used to build a broad band energy spectrum (scientific ratemeters) organized in 11 bands for each of the two MCAL detection planes, with a time resolution of 1 second. After the first engineering commissioning phase, following the AGILE launch on 23rd April 2007, between 22nd June and 5th November 2007 eighteen GRBs were detected offline in the scientific ratemeters data, with a detection rate of about one per week. In this paper the capabilities of the detector will be described and an overview of the first detected GRBs will be given.

Maxdose-SR and popdose-SR routine release atmospheric dose models used at SRS

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

Jannik, G. T.; Trimor, P. P.

MAXDOSE-SR and POPDOSE-SR are used to calculate dose to the offsite Reference Person and to the surrounding Savannah River Site (SRS) population respectively following routine releases of atmospheric radioactivity. These models are currently accessed through the Dose Model Version 2014 graphical user interface (GUI). MAXDOSE-SR and POPDOSE-SR are personal computer (PC) versions of MAXIGASP and POPGASP, which both resided on the SRS IBM Mainframe. These two codes follow U.S. Nuclear Regulatory Commission (USNRC) Regulatory Guides 1.109 and 1.111 (1977a, 1977b). The basis for MAXDOSE-SR and POPDOSE-SR are USNRC developed codes XOQDOQ (Sagendorf et. al 1982) and GASPAR (Eckerman et. almore » 1980). Both of these codes have previously been verified for use at SRS (Simpkins 1999 and 2000). The revisions incorporated into MAXDOSE-SR and POPDOSE-SR Version 2014 (hereafter referred to as MAXDOSE-SR and POPDOSE-SR unless otherwise noted) were made per Computer Program Modification Tracker (CPMT) number Q-CMT-A-00016 (Appendix D). Version 2014 was verified for use at SRS in Dixon (2014).« less

Centroid tracker and aimpoint selection

NASA Astrophysics Data System (ADS)

Venkateswarlu, Ronda; Sujata, K. V.; Venkateswara Rao, B.

1992-11-01

Autonomous fire and forget weapons have gained importance to achieve accurate first pass kill by hitting the target at an appropriate aim point. Centroid of the image presented by a target in the field of view (FOV) of a sensor is generally accepted as the aimpoint for these weapons. Centroid trackers are applicable only when the target image is of significant size in the FOV of the sensor but does not overflow the FOV. But as the range between the sensor and the target decreases the image of the target will grow and finally overflow the FOV at close ranges and the centroid point on the target will keep on changing which is not desirable. And also centroid need not be the most desired/vulnerable point on the target. For hardened targets like tanks, proper aimpoint selection and guidance up to almost zero range is essential to achieve maximum kill probability. This paper presents a centroid tracker realization. As centroid offers a stable tracking point, it can be used as a reference to select the proper aimpoint. The centroid and the desired aimpoint are simultaneously tracked to avoid jamming by flares and also to take care of the problems arising due to image overflow. Thresholding of gray level image to binary image is a crucial step in centroid tracker. Different thresholding algorithms are discussed and a suitable algorithm is chosen. The real-time hardware implementation of centroid tracker with a suitable thresholding technique is presented including the interfacing to a multimode tracker for autonomous target tracking and aimpoint selection. The hardware uses very high speed arithmetic and programmable logic devices to meet the speed requirement and a microprocessor based subsystem for the system control. The tracker has been evaluated in a field environment.

Use of LysoTracker dyes: a flow cytometric study of autophagy.

PubMed

Chikte, Shaheen; Panchal, Neelam; Warnes, Gary

2014-02-01

The flow cytometric use of LysoTracker dyes was employed to investigate the autophagic process and to compare this with the upregulation of autophagy marker, the microtubule-associated protein LC3B. Although the mechanism of action of LysoTracker dyes is not fully understood, they have been used in microscopy to image acidic spherical organelles, and their use in flow cytometry has not been thoroughly investigated in the study of autophagy. This investigation uses numerous autophagy-inducing agents including chloroquine (CQ), rapamycin, low serum (<1%) RPMI, and nutrient starvation to induce autophagy in Jurkat T-cell leukemia and K562 erythromyeloid cell lines. LC3B showed an increase with CQ treatment although this was different to LysoTracker signals in terms of dose and time. Rapamycin, low serum (<1%) RPMI, and nutrient starvation induction of autophagy also induced an increase in LysoTracker and LC3B signals. CQ also induced apoptosis in cell lines, which was blocked by pan-caspase inhibitor z-VAD resulting in a reduction in cells undergoing apoptosis and a subsequent upregulation of autophagic markers LC3B and lysosomal dye signals. Given that LC3B and LysoTracker are measuring different biological events in the autophagic process, they surprisingly both upregulated during autophagic process. This study, however, shows that although LysoTracker dyes do not specifically label lysosomes or autophagosomes within the cell, they allow the simultaneous measurement of an autophagy-related process and other live-cell functions, which are not possible with the standard LC3B antibody-labeling technique. This method has the advantage of other live-cell LCB-GFP-tagged experiments in that be used to analyze patient cells as well as easier to use and significantly less costly. Copyright © 2013 International Society for Advancement of Cytometry.

Using analog instruments in Tracker video-based experiments to understand the phenomena of electricity and magnetism in physics education

NASA Astrophysics Data System (ADS)

Aguilar-Marín, Pablo; Chavez-Bacilio, Mario; Jáuregui-Rosas, Segundo

2018-05-01

Tracker is a piece of freeware software, designed to use video recorded images of the motion of objects as input data, and has been mostly applied in physics education to analyse and simulate physical phenomena in mechanics. In this work we report the application of Tracker to the study of experiments in electricity and magnetism using analog instruments for electrical signal measurements. As we are unable to directly video-track the motion of electrons in electric circuits, the angular deflections of the instruments’ pointers were video captured instead. The kinematic variables (angular position as a function of time) had to be related to the electrical ones (voltages and currents as a function of time). Two well-known experiments in physics teaching, the RC circuit for charging and discharging a capacitor and Faraday electromagnetic induction, were chosen to illustrate the procedures. The third experiment analysed and modeled with Tracker was the rather well-known electromagnetic retardation of disk- or cylinder-shaped magnets falling inside non-magnetic metallic pipes. Instead of metallic pipes we used an aluminum plate with an arrangement of a couple of parallelepiped-shaped magnets falling parallel to the plate. In the three cases studied, the experimental and the Tracker simulation results were in very good agreement. These outcomes show that it is possible to exploit the potential of Tracker software in areas other than mechanics, in areas where electrical signals are involved. The experiments are inexpensive and simple to perform, and are suitable for high school and introductory undergraduate courses in electricity, magnetism and electronics. We propose the use of Tracker combined with analog measuring devices to explore further its applications in electricity, magnetism, electronics and in other experimental sciences where electrical signals are involved.

Characterization of functional variables in epididymal alpaca (Vicugna pacos) sperm using imaging flow cytometry.

PubMed

Santiani, Alexei; Ugarelli, Alejandra; Evangelista-Vargas, Shirley

2016-10-01

Epididymal alpaca sperm represent an alternative model for the study of alpaca semen. The objective of this study was to characterize the normal values of some functional variables in epididymal alpaca sperm using imaging flow cytometry. Alpaca testicles (n=150) were processed and sperm were recovered from the cauda epididymides. Only 76 samples with acceptable motility and sperm count were considered for assessment by imaging flow cytometry. Acrosome integrity and integrity/viability were assessed by FITC-PSA/PI and FITC-PNA/PI. Mitochondrial membrane potential (MMP) was assessed by MitoTracker CMXRos and MitoTracker Deep Red FM. Lipid peroxidation was evaluated using BODIPY 581/591 C11. Results show that the mean values for acrosome-intact sperm were 95.03±6.39% and 93.34±7.96%, using FITC-PSA and FITC-PNA, respectively. The mean values for acrosome-intact viable sperm were 60.58±12.12% with FITC-PSA/PI and 58.81±12.94% with FITC-PNA/PI. Greater MMP was detected in 65.03±15.92% and 59.52±19.19%, using MitoTracker CMXRos and MitoTracker Deep Red FM, respectively. Lipid peroxidation was 0.84±0.95%. Evaluation of acrosome-intact and acrosome-intact viable sperm with FITC-PSA/PI compared with. FITC-PNA/PI or MMP with MitoTracker CMXRos compared with MitoTracker Deep Red FM were correlated (P<0.05). The MMP using MitoTracker CMXRos was the only variable correlated (P<0.05) with sperm motility (r=0.3979). This report provides a basis for future research related to alpaca semen using the epididymal sperm model. Copyright © 2016 Elsevier B.V. All rights reserved.

Minimum Error Bounded Efficient L1 Tracker with Occlusion Detection (PREPRINT)

DTIC Science & Technology

2011-01-01

Minimum Error Bounded Efficient `1 Tracker with Occlusion Detection Xue Mei\\ ∗ Haibin Ling† Yi Wu†[ Erik Blasch‡ Li Bai] \\Assembly Test Technology...proposed BPR-L1 tracker is tested on several challenging benchmark sequences involving chal- lenges such as occlusion and illumination changes. In all...point method de - pends on the value of the regularization parameter λ. In the experiments, we found that the total number of PCG is a few hundred. The

Long-life 3-axis satellite attitude sensing, phase 1

NASA Technical Reports Server (NTRS)

Arild, Tor

1987-01-01

The purpose was to investigate the feasibility of new, moderate-cost, high reliability navigation sensors for high-altitude satellites, using stellar sources to obviate the use of gyroscopic devices. The primary investigation focused on the need for developing a star tracker model to replace an old star tracker which is still needed for current probe and satellite programs. One innovative element of the proposed star tracker was the design, development, and testing of technology components related to a phase scrambler plate. The purpose of the phase scrambler plate is to convert the impulse response of the optical system from a point image to a uniformly bright, square, angularly large, in-focus image of the star source. A collimated star source was built and tested. A breadboard star tracker with an 8 x 8 degree field of view was designed and built. It was tested in normal quad-cell mode (without the phase scrambler plate) and with the phase scrambler plate. Although the phase scrambler plate was crudely made, the performance of the star tracker breadboard was greatly improved using the phase scrambler plate, instead of system defocus. If further developed, the phase scrambler plate may be added as a low-cost retroconversion to any objective lens to greatly improve quad-cell or CCD array tracking; applications include star trackers, laser metrology, laser machining optics, and surveying instrumentation.

Development of a digital mobile solar tracker

NASA Astrophysics Data System (ADS)

Baidar, S.; Kille, N.; Ortega, I.; Sinreich, R.; Thomson, D.; Hannigan, J.; Volkamer, R.

2015-11-01

We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV-Vis and FTIR spectrometers making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun Differential Optical Absorption Spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Photochemistry and Pollution Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives, and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution, and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.

Development of a digital mobile solar tracker

NASA Astrophysics Data System (ADS)

Baidar, Sunil; Kille, Natalie; Ortega, Ivan; Sinreich, Roman; Thomson, David; Hannigan, James; Volkamer, Rainer

2016-03-01

We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV-Vis and Fourier transform infrared spectrometers, making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun differential optical absorption spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.

Utility of the T2 Mood Tracker mobile application among army warrior transition unit service members.

PubMed

Bush, Nigel E; Ouellette, Gary; Kinn, Julie

2014-12-01

Many military personnel returning from deployment experience increases in psychological symptoms, including post-traumatic stress disorder (PTSD), depression, and mood changes. Patient health diaries are commonly used for self-reporting over time away from the clinic. "T2 Mood Tracker" is an application ("app") for smartphones and other mobile devices that enables users to rate their moods, to self-monitor across time, and to report their emotional experiences to health providers. We designed T2 Mood Tracker to track symptoms associated with deployment-related behavioral health issues, including PTSD, Head Injury, Stress, Depression, Anxiety, and General Well-Being. We field-tested T2 Mood Tracker with a small sample of redeployed soldiers under treatment for behavioral health issues at a Warrior Transition Unit. Participants used the app an average of 10 different days over the 2- to 3-week test period. Consensus was that T2 Mood Tracker was easy to use, useful and beneficial. The majority said they would use the app in the future, would recommend it to other service members, and would use the app to share their mood information with a provider. Warrior Transition Unit providers were enthusiastic about the potential of T2 Mood Tracker as a tool for use with their patients. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

Application of virtual distances methodology to laser tracker verification with an indexed metrology platform

NASA Astrophysics Data System (ADS)

Acero, R.; Santolaria, J.; Pueo, M.; Aguilar, J. J.; Brau, A.

2015-11-01

High-range measuring equipment like laser trackers need large dimension calibrated reference artifacts in their calibration and verification procedures. In this paper, a new verification procedure for portable coordinate measuring instruments based on the generation and evaluation of virtual distances with an indexed metrology platform is developed. This methodology enables the definition of an unlimited number of reference distances without materializing them in a physical gauge to be used as a reference. The generation of the virtual points and reference lengths derived is linked to the concept of the indexed metrology platform and the knowledge of the relative position and orientation of its upper and lower platforms with high accuracy. It is the measuring instrument together with the indexed metrology platform one that remains still, rotating the virtual mesh around them. As a first step, the virtual distances technique is applied to a laser tracker in this work. The experimental verification procedure of the laser tracker with virtual distances is simulated and further compared with the conventional verification procedure of the laser tracker with the indexed metrology platform. The results obtained in terms of volumetric performance of the laser tracker proved the suitability of the virtual distances methodology in calibration and verification procedures for portable coordinate measuring instruments, broadening and expanding the possibilities for the definition of reference distances in these procedures.

Miniature Laser Tracker

DOEpatents

Vann, Charles S.

2003-09-09

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

Semiconductor structure and recess formation etch technique

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

Lu, Bin; Sun, Min; Palacios, Tomas Apostol

2017-02-14

A semiconductor structure has a first layer that includes a first semiconductor material and a second layer that includes a second semiconductor material. The first semiconductor material is selectively etchable over the second semiconductor material using a first etching process. The first layer is disposed over the second layer. A recess is disposed at least in the first layer. Also described is a method of forming a semiconductor structure that includes a recess. The method includes etching a region in a first layer using a first etching process. The first layer includes a first semiconductor material. The first etching processmore » stops at a second layer beneath the first layer. The second layer includes a second semiconductor material.« less

A novel design of dual-channel optical system of star-tracker based on non-blind area PAL system

NASA Astrophysics Data System (ADS)

Luo, Yujie; Bai, Jian

2016-07-01

Star-tracker plays an important role in satellite navigation. Considering the satellites on near-Earth orbit, the system usually has two optical systems: one for observing the profile of Earth and the other for capturing the positions of stars. In this paper, we demonstrate a novel kind of dual-channel optical observation system of star-tracker with non-blind area PAL imaging system based on dichroic filter, which can combine both different observation channels into an integrated structure and realize the feature of miniaturization. According to the practical usage of star-tracker and the features of dichroic filter, we set the ultraviolet band as the PAL channel to observe the Earth with the FOV ranging from 40°-60°, and set the visible band as the front imaging channel to capture the stars far away from this system with the FOV ranging from 0°-20°. Consequently, the rays of both channels are converged on the same image plane, improving the efficiency of pixels of detector and reducing the weight and size of whole star-tracker system.

Ground Testing Strategies for Verifying the Slew Rate Tolerance of Star Trackers

PubMed Central

Dzamba, Tom; Enright, John

2014-01-01

The performance of a star tracker is largely based on the availability of its attitude solution. Several methods exist to assess star tracker availability under both static and dynamic imaging conditions. However, these methods typically make various idealizations that can limit the accuracy of these results. This study aims to increase the fidelity of star tracker availability modeling by accounting for the effects of detection logic and pixel saturation on star detection. We achieve this by developing an analytical model for the focal plane intensity distribution of a star in the presence of sensor slew. Using the developed model, we examine the effects of slew rate on star detection using simulations and lab tests. The developed approach allows us to determine the maximum slew rate for which a star of a given stellar magnitude can still be detected. This information can then be used to describe the availability of a star tracker attitude solution as a function of slew rate, both spatially, across the entire celestial sphere, or locally, along a specified orientation track. PMID:24577522

Effective Visual Tracking Using Multi-Block and Scale Space Based on Kernelized Correlation Filters

PubMed Central

Jeong, Soowoong; Kim, Guisik; Lee, Sangkeun

2017-01-01

Accurate scale estimation and occlusion handling is a challenging problem in visual tracking. Recently, correlation filter-based trackers have shown impressive results in terms of accuracy, robustness, and speed. However, the model is not robust to scale variation and occlusion. In this paper, we address the problems associated with scale variation and occlusion by employing a scale space filter and multi-block scheme based on a kernelized correlation filter (KCF) tracker. Furthermore, we develop a more robust algorithm using an appearance update model that approximates the change of state of occlusion and deformation. In particular, an adaptive update scheme is presented to make each process robust. The experimental results demonstrate that the proposed method outperformed 29 state-of-the-art trackers on 100 challenging sequences. Specifically, the results obtained with the proposed scheme were improved by 8% and 18% compared to those of the KCF tracker for 49 occlusion and 64 scale variation sequences, respectively. Therefore, the proposed tracker can be a robust and useful tool for object tracking when occlusion and scale variation are involved. PMID:28241475

Effective Visual Tracking Using Multi-Block and Scale Space Based on Kernelized Correlation Filters.

PubMed

Jeong, Soowoong; Kim, Guisik; Lee, Sangkeun

2017-02-23

Accurate scale estimation and occlusion handling is a challenging problem in visual tracking. Recently, correlation filter-based trackers have shown impressive results in terms of accuracy, robustness, and speed. However, the model is not robust to scale variation and occlusion. In this paper, we address the problems associated with scale variation and occlusion by employing a scale space filter and multi-block scheme based on a kernelized correlation filter (KCF) tracker. Furthermore, we develop a more robust algorithm using an appearance update model that approximates the change of state of occlusion and deformation. In particular, an adaptive update scheme is presented to make each process robust. The experimental results demonstrate that the proposed method outperformed 29 state-of-the-art trackers on 100 challenging sequences. Specifically, the results obtained with the proposed scheme were improved by 8% and 18% compared to those of the KCF tracker for 49 occlusion and 64 scale variation sequences, respectively. Therefore, the proposed tracker can be a robust and useful tool for object tracking when occlusion and scale variation are involved.

Development and Testing of the AMEGO Silicon Tracker System

NASA Astrophysics Data System (ADS)

Griffin, Sean; Amego Team

2018-01-01

The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe-class mission in consideration for the 2020 decadal review designed to operate at energies from ˜ 200 keV to > 10 GeV. Operating a detector in this energy regime is challenging due to the crossover in the interaction cross-section for Compton scattering and pair production. AMEGO is made of four major subsystems: a plastic anticoincidence detector for rejecting cosmic-ray events, a silicon tracker for measuring the energies of Compton scattered electrons and pair-production products, a CZT calorimeter for measuring the energy and location of Compton scattered photons, and a CsI calorimeter for measuring the energy of the pair-production products at high energies. The tracker comprises layers of dual-sided silicon strip detectors which provide energy and localization information for Compton scattering and pair-production events. A prototype tracker system is under development at GSFC; in this contribution we provide details on the verification, packaging, and testing of the prototype tracker, as well as present plans for the development of the front-end electronics, beam tests, and a balloon flight.

Long Term Outdoor Testing of Low Concentration Solar Modules

NASA Astrophysics Data System (ADS)

Fraas, Lewis; Avery, James; Minkin, Leonid; Huang, H. X.; Hebrink, Tim; Hurt, Rik; Boehm, Robert

2011-12-01

A 1-axis carousel tracker equipped with four 3-sun low-concentration mirror modules has now been under test outdoors at the University of Nevada in Las Vegas (UNLV) for three years. There are three unique features associated with this unit. First, simple linear mirrors are used to reduce the amount of expensive single crystal silicon in order to potentially lower the module cost while potentially maintaining cell efficiencies over 20% and high module efficiency. Simple linear mirrors also allow the use of a single axis tracker. Second, the azimuth carousel tracker is also unique allowing trackers to be used on commercial building rooftops. Third, an experiment is underway comparing aluminum based mirrors with novel 3M Company multilayer polymeric mirrors which are potentially very low cost. Comparing the data from March of 2008 through March of 2011 shows that the aluminum mirror degradation to date is negligible and that the carousel tracker has been operating continuously and reliable. Also, no degradation has been observed for the 3M brand cool mirrors after one year in use.

Robust visual tracking via multiscale deep sparse networks

NASA Astrophysics Data System (ADS)

Wang, Xin; Hou, Zhiqiang; Yu, Wangsheng; Xue, Yang; Jin, Zefenfen; Dai, Bo

2017-04-01

In visual tracking, deep learning with offline pretraining can extract more intrinsic and robust features. It has significant success solving the tracking drift in a complicated environment. However, offline pretraining requires numerous auxiliary training datasets and is considerably time-consuming for tracking tasks. To solve these problems, a multiscale sparse networks-based tracker (MSNT) under the particle filter framework is proposed. Based on the stacked sparse autoencoders and rectifier linear unit, the tracker has a flexible and adjustable architecture without the offline pretraining process and exploits the robust and powerful features effectively only through online training of limited labeled data. Meanwhile, the tracker builds four deep sparse networks of different scales, according to the target's profile type. During tracking, the tracker selects the matched tracking network adaptively in accordance with the initial target's profile type. It preserves the inherent structural information more efficiently than the single-scale networks. Additionally, a corresponding update strategy is proposed to improve the robustness of the tracker. Extensive experimental results on a large scale benchmark dataset show that the proposed method performs favorably against state-of-the-art methods in challenging environments.

Method of making photovoltaic cell

DOEpatents

Cruz-Campa, Jose Luis; Zhou, Xiaowang; Zubia, David

2017-06-20

A photovoltaic solar cell comprises a nano-patterned substrate layer. A plurality of nano-windows are etched into an intermediate substrate layer to form the nano-patterned substrate layer. The nano-patterned substrate layer is positioned between an n-type semiconductor layer composed of an n-type semiconductor material and a p-type semiconductor layer composed of a p-type semiconductor material. Semiconductor material accumulates in the plurality of nano-windows, causing a plurality of heterojunctions to form between the n-type semiconductor layer and the p-type semiconductor layer.

Developmental Milestones

MedlinePlus

... 3 years 4 years 5 years Milestone Tracker App Milestones in Action: Photos & Videos 2 months 4 ... milestone checklists (PDF) Download the Milestone Tracker mobile app View the Milestones in Action photo and video ...

75 FR 5996 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-05

... and OMB Number: Synchronized Predeployment and Operational Tracker (SPOT) System; OMB Control Number... Operational Tracker (SPOT) System before deployment outside the United States. Data collection on contractors...

Intelligent robotic tracker

NASA Technical Reports Server (NTRS)

Otaguro, W. S.; Kesler, L. O.; Land, K. C.; Rhoades, D. E.

1987-01-01

An intelligent tracker capable of robotic applications requiring guidance and control of platforms, robotic arms, and end effectors has been developed. This packaged system capable of supervised autonomous robotic functions is partitioned into a multiple processor/parallel processing configuration. The system currently interfaces to cameras but has the capability to also use three-dimensional inputs from scanning laser rangers. The inputs are fed into an image processing and tracking section where the camera inputs are conditioned for the multiple tracker algorithms. An executive section monitors the image processing and tracker outputs and performs all the control and decision processes. The present architecture of the system is presented with discussion of its evolutionary growth for space applications. An autonomous rendezvous demonstration of this system was performed last year. More realistic demonstrations in planning are discussed.

Context Aware Programmable Trackers for the Next Generation Internet

NASA Astrophysics Data System (ADS)

Sousa, Pedro

This work introduces and proposes the concept of context aware programmable trackers for the next generation Internet. The proposed solution gives ground for the development of advanced applications based on the P2P paradigm and will foster collaborative efforts among several network entities (e.g. P2P applications and ISPs). The proposed concept of context aware programmable trackers allows that several peer selection strategies might be supported by a P2P tracker entity able to improve the peer selection decisions according with pre-defined objectives and external inputs provided by specific services. The flexible, adaptive and enhanced peer selection semantics that might be achieved by the proposed solution will contribute for devising novel P2P based services and business models for the future Internet.

Optical orientation in ferromagnet/semiconductor hybrids

NASA Astrophysics Data System (ADS)

Korenev, V. L.

2008-11-01

The physics of optical pumping of semiconductor electrons in ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of a ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of a semiconductor. Spin-spin interactions near the ferromagnet/semiconductor interface play a crucial role in the optical readout and the manipulation of ferromagnetism.

Fabrication of Metallic Hollow Nanoparticles

NASA Technical Reports Server (NTRS)

Lillehei, Peter T. (Inventor); Chu, Sang-Hyon (Inventor); Park, Yeonjoon (Inventor); Kim, Jae-Woo (Inventor); Choi, Sr., Sang H. (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

2016-01-01

Metal and semiconductor nanoshells, particularly transition metal nanoshells, are fabricated using dendrimer molecules. Metallic colloids, metallic ions or semiconductors are attached to amine groups on the dendrimer surface in stabilized solution for the surface seeding method and the surface seedless method, respectively. Subsequently, the process is repeated with additional metallic ions or semiconductor, a stabilizer, and NaBH.sub.4 to increase the wall thickness of the metallic or semiconductor lining on the dendrimer surface. Metallic or semiconductor ions are automatically reduced on the metallic or semiconductor nanoparticles causing the formation of hollow metallic or semiconductor nanoparticles. The void size of the formed hollow nanoparticles depends on the dendrimer generation. The thickness of the metallic or semiconductor thin film around the dendrimer depends on the repetition times and the size of initial metallic or semiconductor seeds.

78 FR 38695 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-27

..., Associated Form and OMB Number: Synchronized Predeployment and Operational Tracker (SPOT) System; OMB Control... Operational Tracker (SPOT) System before deployment outside of the United States. Data collection on...

Optical contacting for gravity probe star tracker

NASA Technical Reports Server (NTRS)

Wright, J. J.; Zissa, D. E.

1984-01-01

A star-tracker telescope, constructed entirely of fused silica elements optically contacted together, has been proposed to provide submilliarc-second pointing accuracy for Gravity Probe. A bibliography and discussion on optical contacting (the bonding of very flat, highly polished surfaces without the use of adhesives) are presented. Then results from preliminary experiments on the strength of optical contacts including a tensile strength test in liquid helium are discussed. Suggestions are made for further study to verify an optical contacting method for the Gravity Probe star-tracker telescope.

Which Eye Tracker is Right for Your Research Performance Evaluation of Several Cost Variant Eye Trackers

DTIC Science & Technology

2016-09-19

REPORT TYPE 3. DATES COVERED (From - To) 21-10-16 Conference Proceedings 10/2015 – 03/2016 4. TITLE AND SUBTITLE Which eye tracker is right for...Force Research Laboratory 711th Human Performance Wing Airman Systems Directorate Warfighter Interface Division Applied Neuroscience Branch Wright...88ABW-2016-1334; Human Factors and Ergonomics Society 2016 Annual Meeting 19 – 23 Sept 2016 14. Though not often mentioned, the price point of many

Radiation-Hard Breadboard Star Tracker. Attachment 1.

DTIC Science & Technology

1985-09-01

fdL RETURN DONE !! * . *• , . -+., -• -: . . E+ . . .. j , ’ - - V.r.*r - , It - ’Cjf0 Q -****r.. ... " * *. " . -. tu ’ * Checkadapt 3- 2"Jj...TRACK POSITION, it will use the 3 70! CURRENT STAR #, X POSITION, Y POSITION for 5180 ! information sent to the tracker interface. 7_390 5t0 0 Track _it...CRITERIA which is currently defines as the number of times 57 20 ! the tracker will try and track the star before it is dropped, 5730 it will also

Star tracker error analysis: Roll-to-pitch nonorthogonality

NASA Technical Reports Server (NTRS)

Corson, R. W.

1979-01-01

An error analysis is described on an anomaly isolated in the star tracker software line of sight (LOS) rate test. The LOS rate cosine was found to be greater than one in certain cases which implied that either one or both of the star tracker measured end point unit vectors used to compute the LOS rate cosine had lengths greater than unity. The roll/pitch nonorthogonality matrix in the TNB CL module of the IMU software is examined as the source of error.

Method of physical vapor deposition of metal oxides on semiconductors

DOEpatents

Norton, David P.

2001-01-01

A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

Semiconductor Lasers and Their Application in Optical Fiber Communication.

ERIC Educational Resources Information Center

Agrawal, Govind P.

1985-01-01

Working principles and operating characteristics of the extremely compact and highly efficient semiconductor lasers are explained. Topics include: the p-n junction; Fabry-Perot cavity; heterostructure semiconductor lasers; materials; emission characteristics; and single-frequency semiconductor lasers. Applications for semiconductor lasers include…

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

Dahal, Rajendra P.; Bhat, Ishwara B.; Chow, Tat-Sing

Methods for facilitating fabricating semiconductor structures are provided which include: providing a multilayer structure including a semiconductor layer, the semiconductor layer including a dopant and having an increased conductivity; selectively increasing, using electrochemical processing, porosity of the semiconductor layer, at least in part, the selectively increasing porosity utilizing the increased conductivity of the semiconductor layer; and removing, at least in part, the semiconductor layer with the selectively increased porosity from the multilayer structure. By way of example, the selectively increasing porosity may include selectively, anodically oxidizing, at least in part, the semiconductor layer of the multilayer structure.

Method for removing semiconductor layers from salt substrates

DOEpatents

Shuskus, Alexander J.; Cowher, Melvyn E.

1985-08-27

A method is described for removing a CVD semiconductor layer from an alkali halide salt substrate following the deposition of the semiconductor layer. The semiconductor-substrate combination is supported on a material such as tungsten which is readily wet by the molten alkali halide. The temperature of the semiconductor-substrate combination is raised to a temperature greater than the melting temperature of the substrate but less than the temperature of the semiconductor and the substrate is melted and removed from the semiconductor by capillary action of the wettable support.

Photovoltaic cell with nano-patterned substrate

DOEpatents

Cruz-Campa, Jose Luis; Zhou, Xiaowang; Zubia, David

2016-10-18

A photovoltaic solar cell comprises a nano-patterned substrate layer. A plurality of nano-windows are etched into an intermediate substrate layer to form the nano-patterned substrate layer. The nano-patterned substrate layer is positioned between an n-type semiconductor layer composed of an n-type semiconductor material and a p-type semiconductor layer composed of a p-type semiconductor material. Semiconductor material accumulates in the plurality of nano-windows, causing a plurality of heterojunctions to form between the n-type semiconductor layer and the p-type semiconductor layer.

Separating semiconductor devices from substrate by etching graded composition release layer disposed between semiconductor devices and substrate including forming protuberances that reduce stiction

DOEpatents

Tauke-Pedretti, Anna; Nielson, Gregory N; Cederberg, Jeffrey G; Cruz-Campa, Jose Luis

2015-05-12

A method includes etching a release layer that is coupled between a plurality of semiconductor devices and a substrate with an etch. The etching includes etching the release layer between the semiconductor devices and the substrate until the semiconductor devices are at least substantially released from the substrate. The etching also includes etching a protuberance in the release layer between each of the semiconductor devices and the substrate. The etch is stopped while the protuberances remain between each of the semiconductor devices and the substrate. The method also includes separating the semiconductor devices from the substrate. Other methods and apparatus are also disclosed.

Dye-Sensitized Approaches to Photovoltaics

NASA Astrophysics Data System (ADS)

Grätzel, Michael

2008-03-01

Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely reaction of such a hole is the photocorrosion of the semiconductor itself. However, only relatively narrow band-gap materials have an effective optical absorption through the visible spectrum, towards and into the infra-red. Materials with an optimal band-gap match to the solar spectrum, of the order of 1.5eV, are therefore electrochemically unstable. A stable photoelectrochemical cell, without some process of optical sensitization, and necessarily using a wide-gap semiconductor is sensitive only to the ultra-violet limit of the visible spectrum. Over recent years a suitable combination of semiconductor and sensitizer has been identified and optimized, so that now a solar spectrum conversion efficiency of over 11% has been verified in a sensitized photoelectrochemical device. One key to such an efficient system is the suppression of recombination losses. When the excited dye relaxes by electron loss, the separated charge carriers find themselves on opposite sides of a phase barrier -- the electron within the solid-state semiconductor, the positive charge externally, in association with the dye molecule. There is no valence---band involvement in the process, so the system represents a majority-carrier device, avoiding one of the major loss mechanisms in conventional photovoltaics. In consequence also a highly-disordered, even porous, semiconductor structure is acceptable, enabling surface adsorption of a sufficient concentration of the dye to permit total optical absorption of incident light of photon energy greater than the HOMO-LUMO gap of the dye molecule. The accepted wide-band semiconductor for photoelectrochemical applications is titanium dioxide in the anatase crystal structure. The size of the nanocrystals making up the semiconductor photoanode can be determined by hydrothermal processing of a precursor sol, and the film can be deposited on a transparent conducting oxide (TCO) substrate by any convenient thin-film process such as screen printing or tape casting. The preferred dye system is inspired by the natural processes involving chlorophyll, the coloring material in plants on which all earthly life depends. Chlorophyll is an organometallic dye, with a metal ion, Mg, within a porphyrin cage of nitrogen atoms. The synthetic chemist of course can select any convenient metal within the periodic table, and experience shows that ruthenium has the optimal properties expected. A ruthenium-pyridyl complex provides the chromophore of the dye, with the HOMO-LUMO gap, and thence the absorption spectrum bring modified by substitution with thiocyanide groups. Chemisorptive attachment of the dye to the metal oxide surface is obtained by carboxyl groups attached to the pyridyl components. The energetics of the dye is such that the LUMO level is just above the conduction band edge of the semiconductor, enabling relaxation by electron injection as required. A satisfactory electroactive dye structure, with good attachment properties and a wide optical absorption spectrum is therefore a sophisticated molecular engineering product. The electrolyte is also an optimized electrochemical system. The basic redox behavior is provided by the iodine/iodide system, with the advantage that the ions, both oxidized and reduced are relatively small, and therefore mobile in the supporting electrolyte. Energy losses due to slow diffusion are minimized. Early experiments used aqueous electrolytes, though with limited cell lifetime due to hydrolysis of the chemisorptive dye---semiconductor bond. A wide range of organic systems were therefore investigated, with the present favored formulation being based on imidazole salts. These have the additional advantage of low vapor pressure, very necessary as the photoactive sites under mid---day sun illumination may reach 80 C or higher. Low losses at the cathode counterelectrode are also a requirement for cell efficiency. The cathode is not necessarily transparent, and prototype cells on thin metal foils have been produced. However a TCO on glass or polymer counterelectrode is widely used. In either case suitable electrocatalytic behavior is required and frequently a nanodispersed Pt precipitated from haxachloride solution is employed. It is by now evident that the achievement of an industrially-competitive sensitized photoelectrochemical solar cell is the result of the optimization of several components, associated obviously with their effective synergy. Each change of a single component has repercussions on the choice and performance of others. However as already mentioned an efficiency of over 11% has now been certified, and a stability of over 14,000 hours under accelerated testing with continuous simulated AM1.5 illumination was recently reported. In consequence there is increasing confidence on the part of industry. Several licensees of EPFL patents on dye---sensitized photovoltaic systems are now preparing for large-scale production. G24 Innovations PLC in Wales is commissioning a manufacturing plant, and Dyesol PLC in Australia is making available the required materials on an industrial scale. In conclusion, then, it can be stated that the DSC system is much more than a fascinating scientific artifact illustrating charge-transfer mechanisms at electrochemical interfaces; an efficiency and reliability with industrial credibility have been demonstrated and verified, and a significant role in competition with other photosystems can be foreseen.

Reducing leakage current in semiconductor devices

DOEpatents

Lu, Bin; Matioli, Elison de Nazareth; Palacios, Tomas Apostol

2018-03-06

A semiconductor device includes a first region having a first semiconductor material and a second region having a second semiconductor material. The second region is formed over the first region. The semiconductor device also includes a current blocking structure formed in the first region between first and second terminals of the semiconductor device. The current blocking structure is configured to reduce current flow in the first region between the first and second terminals.

Autonomous star sensor ASTRO APS: flight experience on Alphasat

NASA Astrophysics Data System (ADS)

Schmidt, U.; Fiksel, T.; Kwiatkowski, A.; Steinbach, I.; Pradarutti, B.; Michel, K.; Benzi, E.

2015-06-01

Jena-Optronik GmbH, located in Jena/Germany, has profound experience in designing and manufacturing star trackers since the early 80s. Today the company has a worldwide leading position in supplying geo-stationary and Earth observation satellites with robust and reliable star tracker systems. In the first decade of the new century Jena-Optronik received a development contract (17317/2003/F/WE) from the European Space Agency to establish the technologically challenging elements for which advanced star tracker technologies as CMOS Active Pixel Sensors were being introduced or were considered strategic. This activity was performed in the frame of the Alphabus large platform pre-development lead by ESA and the industrial Joint Project Team consisting of Astrium (now Airbus Defence and Space), Thales Alenia Space and CNES (Centre national d'études spatiales). The new autonomous star tracker, ASTRO APS (Active Pixel Sensor), extends the Jena-Optronik A stro-series CCD-based star tracker products taken the full benefit of the CMOS APS technology. ASTRO APS is a fully autonomous compact star tracker carrying either the space-qualified radiation hard STAR1000 or the HAS2 APS detectors. The star tracker is one of four Technology Demonstration Payloads (TDP6) carried by Alphasat as hosted payload in the frame of a successful Private Public Partnership between ESA and Inmarsat who owns and operates the satellite as part of its geo-stationary communication satellites fleet. TDP6 supports also directly TDP1, a Laser Communication Terminal, for fine pointing tasks. Alphasat was flawlessly brought in orbit at the end of July 2013 by a European Ariane 5 launcher. Only a few hours after launch the star tracker received its switch ON command and acquired nominally within 6 s the inertial 3-axes attitude. In the following days of the early in-orbit operations of Alphasat the TDP6 unit tracked reliably all the spacecraft maneuvers including the 0.1 and 0.2°/s spin stabilization for Sun pointing, all of the apogee engine thrusts, Moon field of view transits and recovered to stable tracking after several Earth and Sun blindings before the spacecraft entered a preliminary Earth pointing in a nominal geo-stationary attitude. The Jena-Optronik TDP6 operation center received daily the star tracker status and attitude data. The huge amount of acquired raw data has been evaluated to characterize the ASTRO APS (STAR1000) star tracker in-orbit performance. The paper will present in detail these data processing activities and will show the extraordinary good results. Due to the diverse transfer orbit satellite operations the key performance star tracker data like attitude random noise, single star noise, star brightness measurement, baffle Sun exclusion angle, temperature control, etc., could be derived and have been compared to the ground based laboratory and field measurements. The ultimate performance parameters achieved and verified as well as the lessons learned from the comparison to the ground test data are summarized in the conclusion of the paper.

Star Identification Without Attitude Knowledge: Testing with X-Ray Timing Experiment Data

NASA Technical Reports Server (NTRS)

Ketchum, Eleanor

1997-01-01

As the budget for the scientific exploration of space shrinks, the need for more autonomous spacecraft increases. For a spacecraft with a star tracker, the ability to determinate attitude from a lost in space state autonomously requires the capability to identify the stars in the field of view of the tracker. Although there have been efforts to produce autonomous star trackers which perform this function internally, many programs cannot afford these sensors. The author previously presented a method for identifying stars without a priori attitude knowledge specifically targeted for onboard computers as it minimizes the necessary computer storage. The method has previously been tested with simulated data. This paper provides results of star identification without a priori attitude knowledge using flight data from two 8 by 8 degree charge coupled device star trackers onboard the X-Ray Timing Experiment.

A Brightness-Referenced Star Identification Algorithm for APS Star Trackers

PubMed Central

Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

2014-01-01

Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4∼5 times that of the pyramid method and 35∼37 times that of the geometric method. PMID:25299950

A brightness-referenced star identification algorithm for APS star trackers.

PubMed

Zhang, Peng; Zhao, Qile; Liu, Jingnan; Liu, Ning

2014-10-08

Star trackers are currently the most accurate spacecraft attitude sensors. As a result, they are widely used in remote sensing satellites. Since traditional charge-coupled device (CCD)-based star trackers have a limited sensitivity range and dynamic range, the matching process for a star tracker is typically not very sensitive to star brightness. For active pixel sensor (APS) star trackers, the intensity of an imaged star is valuable information that can be used in star identification process. In this paper an improved brightness referenced star identification algorithm is presented. This algorithm utilizes the k-vector search theory and adds imaged stars' intensities to narrow the search scope and therefore increase the efficiency of the matching process. Based on different imaging conditions (slew, bright bodies, etc.) the developed matching algorithm operates in one of two identification modes: a three-star mode, and a four-star mode. If the reference bright stars (the stars brighter than three magnitude) show up, the algorithm runs the three-star mode and efficiency is further improved. The proposed method was compared with other two distinctive methods the pyramid and geometric voting methods. All three methods were tested with simulation data and actual in orbit data from the APS star tracker of ZY-3. Using a catalog composed of 1500 stars, the results show that without false stars the efficiency of this new method is 4~5 times that of the pyramid method and 35~37 times that of the geometric method.

ALF: a facility for x-ray lithography II--a progress report

NASA Astrophysics Data System (ADS)

Lesoine, L. G.; Kukkonen, Kenneth W.; Leavey, Jeffrey A.

1992-07-01

In our previous paper which we presented here two years ago, we described the ALF (Advanced Lithography Facility), IBM's new facility for X-ray lithography which was built as an addition to the Advanced Semiconductor Technology Center at IBM's semiconductor plant in Hopewell Jct., NY. At that time, we described the structure, its utilities, facilities and special features such as the radiation shielding, control room, clean room and vibration resistant design. The building has been completed and occupied. By the time this paper is presented the storage ring will be commissioned, the clean room occupied, and two beamlines with one stepper operational. In this paper we will review the successful completion of the facility with its associated hardware. The installation of the synchrotron will be described elsewhere. We will also discuss the first measurements of vibration, clean room cleanliness and the effectiveness of the radiation shielding. The ALF was completed on schedule and cost objectives were met. This is attributed to careful planning, close cooperation among all the parties involved from the technical team in IBM Research, the system vendor (Oxford Instruments of Oxford England) to the many contractors and subcontractors and to strong support from IBM senior management. All the planned building specifications were met and the facility has come on-line with a minimum of problems. Most important, the initial measurements show that the radiation shielding plan is sound and that with a few modifications the dose limit of 10% of background will be met. Any concerns about an electron accelerator and synchrotron in an industrial setting have been eliminated.

Unitary lens semiconductor device

DOEpatents

Lear, Kevin L.

1997-01-01

A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

Method of doping a semiconductor

DOEpatents

Yang, Chiang Y.; Rapp, Robert A.

1983-01-01

A method for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient.

Coincident site lattice-matched growth of semiconductors on substrates using compliant buffer layers

DOEpatents

Norman, Andrew

2016-08-23

A method of producing semiconductor materials and devices that incorporate the semiconductor materials are provided. In particular, a method is provided of producing a semiconductor material, such as a III-V semiconductor, on a silicon substrate using a compliant buffer layer, and devices such as photovoltaic cells that incorporate the semiconductor materials. The compliant buffer material and semiconductor materials may be deposited using coincident site lattice-matching epitaxy, resulting in a close degree of lattice matching between the substrate material and deposited material for a wide variety of material compositions. The coincident site lattice matching epitaxial process, as well as the use of a ductile buffer material, reduce the internal stresses and associated crystal defects within the deposited semiconductor materials fabricated using the disclosed method. As a result, the semiconductor devices provided herein possess enhanced performance characteristics due to a relatively low density of crystal defects.

Stable surface passivation process for compound semiconductors

DOEpatents

Ashby, Carol I. H.

2001-01-01

A passivation process for a previously sulfided, selenided or tellurated III-V compound semiconductor surface. The concentration of undesired mid-gap surface states on a compound semiconductor surface is reduced by the formation of a near-monolayer of metal-(sulfur and/or selenium and/or tellurium)-semiconductor that is effective for long term passivation of the underlying semiconductor surface. Starting with the III-V compound semiconductor surface, any oxidation present thereon is substantially removed and the surface is then treated with sulfur, selenium or tellurium to form a near-monolayer of chalcogen-semiconductor of the surface in an oxygen-free atmosphere. This chalcogenated surface is then contacted with a solution of a metal that will form a low solubility chalcogenide to form a near-monolayer of metal-chalcogen-semiconductor. The resulting passivating layer provides long term protection for the underlying surface at or above the level achieved by a freshly chalcogenated compound semiconductor surface in an oxygen free atmosphere.

Acceptance of Commercially Available Wearable Activity Trackers Among Adults Aged Over 50 and With Chronic Illness: A Mixed-Methods Evaluation.

PubMed

Mercer, Kathryn; Giangregorio, Lora; Schneider, Eric; Chilana, Parmit; Li, Melissa; Grindrod, Kelly

2016-01-27

Physical inactivity and sedentary behavior increase the risk of chronic illness and death. The newest generation of "wearable" activity trackers offers potential as a multifaceted intervention to help people become more active. To examine the usability and usefulness of wearable activity trackers for older adults living with chronic illness. We recruited a purposive sample of 32 participants over the age of 50, who had been previously diagnosed with a chronic illness, including vascular disease, diabetes, arthritis, and osteoporosis. Participants were between 52 and 84 years of age (mean 64); among the study participants, 23 (72%) were women and the mean body mass index was 31 kg/m(2). Participants tested 5 trackers, including a simple pedometer (Sportline or Mio) followed by 4 wearable activity trackers (Fitbit Zip, Misfit Shine, Jawbone Up 24, and Withings Pulse) in random order. Selected devices represented the range of wearable products and features available on the Canadian market in 2014. Participants wore each device for at least 3 days and evaluated it using a questionnaire developed from the Technology Acceptance Model. We used focus groups to explore participant experiences and a thematic analysis approach to data collection and analysis. Our study resulted in 4 themes: (1) adoption within a comfort zone; (2) self-awareness and goal setting; (3) purposes of data tracking; and (4) future of wearable activity trackers as health care devices. Prior to enrolling, few participants were aware of wearable activity trackers. Most also had been asked by a physician to exercise more and cited this as a motivation for testing the devices. None of the participants planned to purchase the simple pedometer after the study, citing poor accuracy and data loss, whereas 73% (N=32) planned to purchase a wearable activity tracker. Preferences varied but 50% felt they would buy a Fitbit and 42% felt they would buy a Misfit, Jawbone, or Withings. The simple pedometer had a mean acceptance score of 56/95 compared with 63 for the Withings, 65 for the Misfit and Jawbone, and 68 for the Fitbit. To improve usability, older users may benefit from devices that have better compatibility with personal computers or less-expensive Android mobile phones and tablets, and have comprehensive paper-based user manuals and apps that interpret user data. For older adults living with chronic illness, wearable activity trackers are perceived as useful and acceptable. New users may need support to both set up the device and learn how to interpret their data.

Acceptance of Commercially Available Wearable Activity Trackers Among Adults Aged Over 50 and With Chronic Illness: A Mixed-Methods Evaluation

PubMed Central

Mercer, Kathryn; Giangregorio, Lora; Schneider, Eric; Chilana, Parmit; Li, Melissa

2016-01-01

Background Physical inactivity and sedentary behavior increase the risk of chronic illness and death. The newest generation of “wearable” activity trackers offers potential as a multifaceted intervention to help people become more active. Objective To examine the usability and usefulness of wearable activity trackers for older adults living with chronic illness. Methods We recruited a purposive sample of 32 participants over the age of 50, who had been previously diagnosed with a chronic illness, including vascular disease, diabetes, arthritis, and osteoporosis. Participants were between 52 and 84 years of age (mean 64); among the study participants, 23 (72%) were women and the mean body mass index was 31 kg/m2. Participants tested 5 trackers, including a simple pedometer (Sportline or Mio) followed by 4 wearable activity trackers (Fitbit Zip, Misfit Shine, Jawbone Up 24, and Withings Pulse) in random order. Selected devices represented the range of wearable products and features available on the Canadian market in 2014. Participants wore each device for at least 3 days and evaluated it using a questionnaire developed from the Technology Acceptance Model. We used focus groups to explore participant experiences and a thematic analysis approach to data collection and analysis. Results Our study resulted in 4 themes: (1) adoption within a comfort zone; (2) self-awareness and goal setting; (3) purposes of data tracking; and (4) future of wearable activity trackers as health care devices. Prior to enrolling, few participants were aware of wearable activity trackers. Most also had been asked by a physician to exercise more and cited this as a motivation for testing the devices. None of the participants planned to purchase the simple pedometer after the study, citing poor accuracy and data loss, whereas 73% (N=32) planned to purchase a wearable activity tracker. Preferences varied but 50% felt they would buy a Fitbit and 42% felt they would buy a Misfit, Jawbone, or Withings. The simple pedometer had a mean acceptance score of 56/95 compared with 63 for the Withings, 65 for the Misfit and Jawbone, and 68 for the Fitbit. To improve usability, older users may benefit from devices that have better compatibility with personal computers or less-expensive Android mobile phones and tablets, and have comprehensive paper-based user manuals and apps that interpret user data. Conclusions For older adults living with chronic illness, wearable activity trackers are perceived as useful and acceptable. New users may need support to both set up the device and learn how to interpret their data. PMID:26818775

A retrospective analysis of real-world use of the eaTracker® My Goals website by adults from Ontario and Alberta, Canada.

PubMed

Lieffers, Jessica R L; Haresign, Helen; Mehling, Christine; Hanning, Rhona M

2016-09-15

Little is known about use of goal setting and tracking tools within online programs to support nutrition and physical activity behaviour change. In 2011, Dietitians of Canada added "My Goals," a nutrition and physical activity behaviour goal setting and tracking tool to their free publicly available self-monitoring website (eaTracker® ( http://www.eaTracker.ca/ )). My Goals allows users to: a) set "ready-made" SMART (Specific, Measurable, Attainable, Realistic, Time-related) goals (choice of n = 87 goals from n = 13 categories) or "write your own" goals, and b) track progress using the "My Goals Tracker." The purpose of this study was to characterize: a) My Goals user demographics, b) types of goals set, and c) My Goals Tracker use. Anonymous data on all goals set using the My Goals feature from December 6/2012-April 28/2014 by users ≥19y from Ontario and Alberta, Canada were obtained. This dataset contained: anonymous self-reported user demographic data, user set goals, and My Goals Tracker use data. Write your own goals were categorized by topic and specificity. Data were summarized using descriptive statistics. Multivariate binary logistic regression was used to determine associations between user demographics and a) goal topic areas and b) My Goals Tracker use. Overall, n = 16,511 goal statements (75.4 % ready-made; 24.6 % write your own) set by n = 8,067 adult users 19-85y (83.3 % female; mean age 41.1 ± 15.0y, mean BMI 28.8 ± 7.6kg/m(2)) were included for analysis. Overall, 33.1 % of ready-made goals were from the "Managing your Weight" category. Of write your own goal entries, 42.3 % were solely distal goals (most related to weight management); 38.6 % addressed nutrition behaviour change (16.6 % had unspecific general eating goals); 18.1 % addressed physical activity behaviour change (47.3 % had goals without information on exercise amount and type). Many write your own goals were poor quality (e.g., non-specific (e.g., missing amounts)), and possibly unrealistic (e.g., no sugar). Few goals were tracked (<10 %). Demographic variables had statistically significant relations with goal topic areas and My Goals Tracker use. eaTracker® users had high interest in goal setting and the My Goals feature, however, self-written goals were often poor quality and goal tracking was rare. Further research is needed to better support users.

jTracker and Monte Carlo Comparison

NASA Astrophysics Data System (ADS)

Selensky, Lauren; SeaQuest/E906 Collaboration

2015-10-01

SeaQuest is designed to observe the characteristics and behavior of `sea-quarks' in a proton by reconstructing them from the subatomic particles produced in a collision. The 120 GeV beam from the main injector collides with a fixed target and then passes through a series of detectors which records information about the particles produced in the collision. However, this data becomes meaningful only after it has been processed, stored, analyzed, and interpreted. Several programs are involved in this process. jTracker (sqerp) reads wire or hodoscope hits and reconstructs the tracks of potential dimuon pairs from a run, and Geant4 Monte Carlo simulates dimuon production and background noise from the beam. During track reconstruction, an event must meet the criteria set by the tracker to be considered a viable dimuon pair; this ensures that relevant data is retained. As a check, a comparison between a new version of jTracker and Monte Carlo was made in order to see how accurately jTracker could reconstruct the events created by Monte Carlo. In this presentation, the results of the inquest and their potential effects on the programming will be shown. This work is supported by U.S. DOE MENP Grant DE-FG02-03ER41243.

Encoding color information for visual tracking: Algorithms and benchmark.

PubMed

Liang, Pengpeng; Blasch, Erik; Ling, Haibin

2015-12-01

While color information is known to provide rich discriminative clues for visual inference, most modern visual trackers limit themselves to the grayscale realm. Despite recent efforts to integrate color in tracking, there is a lack of comprehensive understanding of the role color information can play. In this paper, we attack this problem by conducting a systematic study from both the algorithm and benchmark perspectives. On the algorithm side, we comprehensively encode 10 chromatic models into 16 carefully selected state-of-the-art visual trackers. On the benchmark side, we compile a large set of 128 color sequences with ground truth and challenge factor annotations (e.g., occlusion). A thorough evaluation is conducted by running all the color-encoded trackers, together with two recently proposed color trackers. A further validation is conducted on an RGBD tracking benchmark. The results clearly show the benefit of encoding color information for tracking. We also perform detailed analysis on several issues, including the behavior of various combinations between color model and visual tracker, the degree of difficulty of each sequence for tracking, and how different challenge factors affect the tracking performance. We expect the study to provide the guidance, motivation, and benchmark for future work on encoding color in visual tracking.

Intelligent modular star and target tracker: a new generation of attitude sensors

NASA Astrophysics Data System (ADS)

Schmidt, Uwe; Strobel, Rainer; Wunder, Dietmar; Graf, Eberhart

2018-04-01

This paper, "Intelligent modular star and target tracker: a new generation of attitude sensors," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

Unitary lens semiconductor device

DOEpatents

Lear, K.L.

1997-05-27

A unitary lens semiconductor device and method are disclosed. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors. 9 figs.

Process for forming shaped group III-V semiconductor nanocrystals, and product formed using process

DOEpatents

Alivisatos, A. Paul; Peng, Xiaogang; Manna, Liberato

2001-01-01

A process for the formation of shaped Group III-V semiconductor nanocrystals comprises contacting the semiconductor nanocrystal precursors with a liquid media comprising a binary mixture of phosphorus-containing organic surfactants capable of promoting the growth of either spherical semiconductor nanocrystals or rod-like semiconductor nanocrystals, whereby the shape of the semiconductor nanocrystals formed in said binary mixture of surfactants is controlled by adjusting the ratio of the surfactants in the binary mixture.

Process for forming shaped group II-VI semiconductor nanocrystals, and product formed using process

DOEpatents

Alivisatos, A. Paul; Peng, Xiaogang; Manna, Liberato

2001-01-01

A process for the formation of shaped Group II-VI semiconductor nanocrystals comprises contacting the semiconductor nanocrystal precursors with a liquid media comprising a binary mixture of phosphorus-containing organic surfactants capable of promoting the growth of either spherical semiconductor nanocrystals or rod-like semiconductor nanocrystals, whereby the shape of the semiconductor nanocrystals formed in said binary mixture of surfactants is controlled by adjusting the ratio of the surfactants in the binary mixture.

Centro-Apical Self-Organization of Organic Semiconductors in a Line-Printed Organic Semiconductor: Polymer Blend for One-Step Printing Fabrication of Organic Field-Effect Transistors

PubMed Central

Jin Lee, Su; Kim, Yong-Jae; Young Yeo, So; Lee, Eunji; Sun Lim, Ho; Kim, Min; Song, Yong-Won; Cho, Jinhan; Ah Lim, Jung

2015-01-01

Here we report the first demonstration for centro-apical self-organization of organic semiconductors in a line-printed organic semiconductor: polymer blend. Key feature of this work is that organic semiconductor molecules were vertically segregated on top of the polymer phase and simultaneously crystallized at the center of the printed line pattern after solvent evaporation without an additive process. The thickness and width of the centro-apically segregated organic semiconductor crystalline stripe in the printed blend pattern were controlled by varying the relative content of the organic semiconductors, printing speed, and solution concentrations. The centro-apical self-organization of organic semiconductor molecules in a printed polymer blend may be attributed to the combination of an energetically favorable vertical phase-separation and hydrodynamic fluids inside the droplet during solvent evaporation. Finally, a centro-apically phase-separated bilayer structure of organic semiconductor: polymer blend was successfully demonstrated as a facile method to form the semiconductor and dielectric layer for OFETs in one- step. PMID:26359068

Centro-Apical Self-Organization of Organic Semiconductors in a Line-Printed Organic Semiconductor: Polymer Blend for One-Step Printing Fabrication of Organic Field-Effect Transistors.

PubMed

Lee, Su Jin; Kim, Yong-Jae; Yeo, So Young; Lee, Eunji; Lim, Ho Sun; Kim, Min; Song, Yong-Won; Cho, Jinhan; Lim, Jung Ah

2015-09-11

Here we report the first demonstration for centro-apical self-organization of organic semiconductors in a line-printed organic semiconductor: polymer blend. Key feature of this work is that organic semiconductor molecules were vertically segregated on top of the polymer phase and simultaneously crystallized at the center of the printed line pattern after solvent evaporation without an additive process. The thickness and width of the centro-apically segregated organic semiconductor crystalline stripe in the printed blend pattern were controlled by varying the relative content of the organic semiconductors, printing speed, and solution concentrations. The centro-apical self-organization of organic semiconductor molecules in a printed polymer blend may be attributed to the combination of an energetically favorable vertical phase-separation and hydrodynamic fluids inside the droplet during solvent evaporation. Finally, a centro-apically phase-separated bilayer structure of organic semiconductor: polymer blend was successfully demonstrated as a facile method to form the semiconductor and dielectric layer for OFETs in one- step.

Retroreflector field tracker. [noncontact optical position sensor for space application

NASA Technical Reports Server (NTRS)

Wargocki, F. E.; Ray, A. J.; Hall, G. E.

1984-01-01

An electrooptical position-measuring instrument, the Retroreflector Field Tracker or RFT, is described. It is part of the Dynamic Augmentation Experiment - a part of the payload of Space Shuttle flight 41-D in Summer 1984. The tracker measures and outputs the position of 23 reflective targets placed on a 32-m solar array to provide data for determination of the dynamics of the lightweight structure. The sensor uses a 256 x 256 pixel CID detector; the processor electronics include three Z-80 microprocessors. A pulsed laser diode illuminator is used.

Understanding usage of a hybrid website and smartphone app for weight management: a mixed-methods study.

PubMed

Morrison, Leanne G; Hargood, Charlie; Lin, Sharon Xiaowen; Dennison, Laura; Joseph, Judith; Hughes, Stephanie; Michaelides, Danius T; Johnston, Derek; Johnston, Marie; Michie, Susan; Little, Paul; Smith, Peter Wf; Weal, Mark J; Yardley, Lucy

2014-10-22

Advancements in mobile phone technology offer huge potential for enhancing the timely delivery of health behavior change interventions. The development of smartphone-based health interventions (apps) is a rapidly growing field of research, yet there have been few longitudinal examinations of how people experience and use these apps within their day-to-day routines, particularly within the context of a hybrid Web- and app-based intervention. This study used an in-depth mixed-methods design to examine individual variation in (1) impact on self-reported goal engagement (ie, motivation, self-efficacy, awareness, effort, achievement) of access to a weight management app (POWeR Tracker) when provided alongside a Web-based weight management intervention (POWeR) and (2) usage and views of POWeR Tracker. Thirteen adults were provided access to POWeR and were monitored over a 4-week period. Access to POWeR Tracker was provided in 2 alternate weeks (ie, weeks 1 and 3 or weeks 2 and 4). Participants' goal engagement was measured daily via self-report. Mixed effects models were used to examine change in goal engagement between the weeks when POWeR Tracker was and was not available and whether the extent of change in goal engagement varied between individual participants. Usage of POWeR and POWeR Tracker was automatically recorded for each participant. Telephone interviews were conducted and analyzed using inductive thematic analysis to further explore participants' experiences using POWeR and POWeR Tracker. Access to POWeR Tracker was associated with a significant increase in participants' awareness of their eating (β1=0.31, P=.04) and physical activity goals (β1=0.28, P=.03). The level of increase varied between individual participants. Usage data showed that participants used the POWeR website for similar amounts of time during the weeks when POWeR Tracker was (mean 29 minutes, SD 31 minutes) and was not available (mean 27 minutes, SD 33 minutes). POWeR Tracker was mostly accessed in short bursts (mean 3 minutes, SD 2 minutes) during convenient moments or moments when participants deemed the intervention content most relevant. The qualitative data indicated that nearly all participants agreed that it was more convenient to access information on-the-go via their mobiles compared to a computer. However, participants varied in their views and usage of the Web- versus app-based components and the informational versus tracking tools provided by POWeR Tracker. This study provides evidence that smartphones have the potential to improve individuals' engagement with their health-related goals when used as a supplement to an existing online intervention. The perceived convenience of mobile access to information does not appear to deter use of Web-based interventions or strengthen the impact of app access on goal engagement. A mixed-methods design enabled exploration of individual variation in daily usage of the app-based tools.

Understanding Usage of a Hybrid Website and Smartphone App for Weight Management: A Mixed-Methods Study

PubMed Central

Hargood, Charlie; Lin, Sharon Xiaowen; Dennison, Laura; Joseph, Judith; Hughes, Stephanie; Michaelides, Danius T; Johnston, Derek; Johnston, Marie; Michie, Susan; Little, Paul; Smith, Peter WF; Weal, Mark J; Yardley, Lucy

2014-01-01

Background Advancements in mobile phone technology offer huge potential for enhancing the timely delivery of health behavior change interventions. The development of smartphone-based health interventions (apps) is a rapidly growing field of research, yet there have been few longitudinal examinations of how people experience and use these apps within their day-to-day routines, particularly within the context of a hybrid Web- and app-based intervention. Objective This study used an in-depth mixed-methods design to examine individual variation in (1) impact on self-reported goal engagement (ie, motivation, self-efficacy, awareness, effort, achievement) of access to a weight management app (POWeR Tracker) when provided alongside a Web-based weight management intervention (POWeR) and (2) usage and views of POWeR Tracker. Methods Thirteen adults were provided access to POWeR and were monitored over a 4-week period. Access to POWeR Tracker was provided in 2 alternate weeks (ie, weeks 1 and 3 or weeks 2 and 4). Participants’ goal engagement was measured daily via self-report. Mixed effects models were used to examine change in goal engagement between the weeks when POWeR Tracker was and was not available and whether the extent of change in goal engagement varied between individual participants. Usage of POWeR and POWeR Tracker was automatically recorded for each participant. Telephone interviews were conducted and analyzed using inductive thematic analysis to further explore participants’ experiences using POWeR and POWeR Tracker. Results Access to POWeR Tracker was associated with a significant increase in participants’ awareness of their eating (β1=0.31, P=.04) and physical activity goals (β1=0.28, P=.03). The level of increase varied between individual participants. Usage data showed that participants used the POWeR website for similar amounts of time during the weeks when POWeR Tracker was (mean 29 minutes, SD 31 minutes) and was not available (mean 27 minutes, SD 33 minutes). POWeR Tracker was mostly accessed in short bursts (mean 3 minutes, SD 2 minutes) during convenient moments or moments when participants deemed the intervention content most relevant. The qualitative data indicated that nearly all participants agreed that it was more convenient to access information on-the-go via their mobiles compared to a computer. However, participants varied in their views and usage of the Web- versus app-based components and the informational versus tracking tools provided by POWeR Tracker. Conclusions This study provides evidence that smartphones have the potential to improve individuals’ engagement with their health-related goals when used as a supplement to an existing online intervention. The perceived convenience of mobile access to information does not appear to deter use of Web-based interventions or strengthen the impact of app access on goal engagement. A mixed-methods design enabled exploration of individual variation in daily usage of the app-based tools. PMID:25355131

Examining the role of dopamine D2 and D3 receptors in Pavlovian conditioned approach behaviors.

PubMed

Fraser, Kurt M; Haight, Joshua L; Gardner, Eliot L; Flagel, Shelly B

2016-05-15

Elucidating the neurobiological mechanisms underlying individual differences in the extent to which reward cues acquire the ability to act as incentive stimuli may contribute to the development of successful treatments for addiction and related disorders. We used the sign-tracker/goal-tracker animal model to examine the role of dopamine D2 and D3 receptors in the propensity to attribute incentive salience to reward cues. Following Pavlovian training, wherein a discrete lever-cue was paired with food reward, rats were classified as sign- or goal-trackers based on the resultant conditioned response. We examined the effects of D2/D3 agonists, 7-OH-DPAT (0.01-0.32mg/kg) or pramipexole (0.032-0.32mg/kg), the D2/D3 antagonist raclopride (0.1mg/kg), and the selective D3 antagonist, SB-277011A (6 or 24mg/kg), on the expression of sign- and goal-tracking conditioned responses. The lever-cue acquired predictive value and elicited a conditioned response for sign- and goal-trackers, but only for sign-trackers did it also acquire incentive value. Following administration of either 7-OH-DPAT, pramipexole, or raclopride, the performance of the previously acquired conditioned response was attenuated for both sign- and goal-trackers. For sign-trackers, the D2/D3 agonist, 7-OH-DPAT, also attenuated the conditioned reinforcing properties of the lever-cue. The selective D3 antagonist did not affect either conditioned response. Alterations in D2/D3 receptor signaling, but not D3 signaling alone, transiently attenuate a previously acquired Pavlovian conditioned response, regardless of whether the response is a result of incentive motivational processes. These findings suggest activity at the dopamine D2 receptor is critical for a reward cue to maintain either its incentive or predictive qualities. Copyright © 2016 Elsevier B.V. All rights reserved.

A refined technique to calculate finite helical axes from rigid body trackers.

PubMed

McLachlin, Stewart D; Ferreira, Louis M; Dunning, Cynthia E

2014-12-01

Finite helical axes (FHAs) are a potentially effective tool for joint kinematic analysis. Unfortunately, no straightforward guidelines exist for calculating accurate FHAs using prepackaged six degree-of-freedom (6 DOF) rigid body trackers. Thus, this study aimed to: (1) describe a protocol for calculating FHA parameters from 6 DOF rigid body trackers using the screw matrix and (2) to maximize the number of accurate FHAs generated from a given data set using a moving window analysis. Four Optotrak® Smart Markers were used as the rigid body trackers, two moving and two fixed, at different distances from the hinge joint of a custom-machined jig. 6D OF pose information was generated from 51 static positions of the jig rotated and fixed in 0.5 deg increments up to 25 deg. Output metrics included the FHA direction cosines, the rotation about the FHA, the translation along the axis, and the intercept of the FHA with the plane normal to the jig's hinge joint. FHA metrics were calculated using the relative tracker rotation from the starting position, and using a moving window analysis to define a minimum acceptable rotational displacement between the moving tracker data points. Data analysis found all FHA rotations calculated from the starting position were within 0.15 deg of the prescribed jig rotation. FHA intercepts were most stable when determined using trackers closest to the hinge axis. Increasing the moving window size improved the FHA direction cosines and center of rotation accuracy. Window sizes larger than 2 deg had an intercept deviation of less than 1 mm. Furthermore, compared to the 0 deg window size, the 2 deg window had a 90% improvement in FHA intercept precision while generating almost an equivalent number of FHA axes. This work identified a solution to improve FHA calculations for biomechanical researchers looking to describe changes in 3D joint motion.

Deep coupling of star tracker and MEMS-gyro data under highly dynamic and long exposure conditions

NASA Astrophysics Data System (ADS)

Sun, Ting; Xing, Fei; You, Zheng; Wang, Xiaochu; Li, Bin

2014-08-01

Star trackers and gyroscopes are the two most widely used attitude measurement devices in spacecrafts. The star tracker is supposed to have the highest accuracy in stable conditions among different types of attitude measurement devices. In general, to detect faint stars and reduce the size of the star tracker, a method with long exposure time method is usually used. Thus, under dynamic conditions, smearing of the star image may appear and result in decreased accuracy or even failed extraction of the star spot. This may cause inaccuracies in attitude measurement. Gyros have relatively good dynamic performance and are usually used in combination with star trackers. However, current combination methods focus mainly on the data fusion of the output attitude data levels, which are inadequate for utilizing and processing internal blurred star image information. A method for tracking deep coupling stars and MEMS-gyro data is proposed in this work. The method achieves deep fusion at the star image level. First, dynamic star image processing is performed based on the angular velocity information of the MEMS-gyro. Signal-to-noise ratio (SNR) of the star spot could be improved, and extraction is achieved more effectively. Then, a prediction model for optimal estimation of the star spot position is obtained through the MEMS-gyro, and an extended Kalman filter is introduced. Meanwhile, the MEMS-gyro drift can be estimated and compensated though the proposed method. These enable the star tracker to achieve high star centroid determination accuracy under dynamic conditions. The MEMS-gyro drift can be corrected even when attitude data of the star tracker are unable to be solved and only one navigation star is captured in the field of view. Laboratory experiments were performed to verify the effectiveness of the proposed method and the whole system.

Examining the Role of Dopamine D2 and D3 Receptors in Pavlovian Conditioned Approach Behaviors

PubMed Central

Fraser, Kurt M.; Haight, Joshua L.; Gardner, Eliot L.; Flagel, Shelly B.

2016-01-01

Elucidating the neurobiological mechanisms underlying individual differences in the extent to which reward cues acquire the ability to act as incentive stimuli may contribute to the development of successful treatments for addiction and related disorders. We used the sign-tracker/goal-tracker animal model to examine the role of dopamine D2 and D3 receptors in the propensity to attribute incentive salience to reward cues. Following Pavlovian training, wherein a discrete lever-cue was paired with food reward, rats were classified as sign- or goal-trackers based on the resultant conditioned response. We examined the effects of D2/D3 agonists, 7-OH-DPAT (0.01–0.32 mg/kg) or pramipexole (0.032–0.32 mg/kg), the D2/D3 antagonist raclopride (0.1 mg/kg), and the selective D3 antagonist, SB-277011A (6 or 24 mg/kg), on the expression of sign- and goal-tracking conditioned responses. The lever-cue acquired predictive value and elicited a conditioned response for sign- and goal-trackers, but only for sign-trackers did it also acquire incentive value. Following administration of either 7-OH-DPAT, pramipexole, or raclopride, the performance of the previously acquired conditioned response was attenuated for both sign- and goal-trackers. For sign-trackers, the D2/D3 agonist, 7-OH-DPAT, also attenuated the conditioned reinforcing properties of the lever-cue. The selective D3 antagonist did not affect either conditioned response. Alterations in D2/D3 receptor signaling, but not D3 signaling alone, transiently attenuate a previously acquired Pavlovian conditioned response, regardless of whether the response is a result of incentive motivational processes. These findings suggest activity at the dopamine D2 receptor is critical for a reward cue to maintain either its incentive or predictive qualities. PMID:26909847

Swarm- Validation of Star Tracker and Accelerometer Data

NASA Astrophysics Data System (ADS)

Schack, Peter; Schlicht, Anja; Pail, Roland; Gruber, Thomas

2016-08-01

The ESA Swarm mission is designed to advance studies in the field of magnetosphere, thermosphere and gravity field. To be fortunate on this task precise knowledge of the orientation of the Swarm satellites is required together with knowledge about external forces acting on the satellites. The key sensors providing this information are the star trackers and the accelerometers. Based on star tracker studies conducted by the Denmark Technical University (DTU), we found interesting patterns in the interboresight angles on all three satellites, which are partly induced by temperature alterations. Additionally, structures of horizontal stripes seem to be caused by the unique distribution of observed stars on the charge-coupled device of the star trackers. Our accelerometer analyses focus on spikes and pulses in the observations. Those short term events on Swarm might originate from electrical processes introduced by sunlight illuminating the nadir foil. Comparisons to GOCE and GRACE are included.

Compressed normalized block difference for object tracking

NASA Astrophysics Data System (ADS)

Gao, Yun; Zhang, Dengzhuo; Cai, Donglan; Zhou, Hao; Lan, Ge

2018-04-01

Feature extraction is very important for robust and real-time tracking. Compressive sensing provided a technical support for real-time feature extraction. However, all existing compressive tracking were based on compressed Haar-like feature, and how to compress many more excellent high-dimensional features is worth researching. In this paper, a novel compressed normalized block difference feature (CNBD) was proposed. For resisting noise effectively in a highdimensional normalized pixel difference feature (NPD), a normalized block difference feature extends two pixels in the original formula of NPD to two blocks. A CNBD feature can be obtained by compressing a normalized block difference feature based on compressive sensing theory, with the sparse random Gaussian matrix as the measurement matrix. The comparative experiments of 7 trackers on 20 challenging sequences showed that the tracker based on CNBD feature can perform better than other trackers, especially than FCT tracker based on compressed Haar-like feature, in terms of AUC, SR and Precision.

Combined Feature Based and Shape Based Visual Tracker for Robot Navigation

NASA Technical Reports Server (NTRS)

Deans, J.; Kunz, C.; Sargent, R.; Park, E.; Pedersen, L.

2005-01-01

We have developed a combined feature based and shape based visual tracking system designed to enable a planetary rover to visually track and servo to specific points chosen by a user with centimeter precision. The feature based tracker uses invariant feature detection and matching across a stereo pair, as well as matching pairs before and after robot movement in order to compute an incremental 6-DOF motion at each tracker update. This tracking method is subject to drift over time, which can be compensated by the shape based method. The shape based tracking method consists of 3D model registration, which recovers 6-DOF motion given sufficient shape and proper initialization. By integrating complementary algorithms, the combined tracker leverages the efficiency and robustness of feature based methods with the precision and accuracy of model registration. In this paper, we present the algorithms and their integration into a combined visual tracking system.

Miniaturized star tracker for micro spacecraft with high angular rate

NASA Astrophysics Data System (ADS)

Li, Jianhua; Li, Zhifeng; Niu, Zhenhong; Liu, Jiaqi

2017-10-01

There is a clear need for miniaturized, lightweight, accurate and inexpensive star tracker for spacecraft with large anglar rate. To face these new constraints, the Beijing Institute of Space Long March Vehicle has designed, built and flown a low cost miniaturized star tracker that provides autonomous ("Lost in Space") inertial attitude determination, 2 Hz 3-axis star tracking, and digital imaging with embedded compression. Detector with high sensitivity is adopted to meet the dynamic and miniature requirement. A Sun and Moon avoiding method based on the calculation of Sun and Moon's vector by astronomical theory is proposed. The produced prototype weight 0.84kg, and can be used for a spacecraft with 6°/s anglar rate. The average angle measure error is less than 43 arc second. The ground verification and application of the star tracker during the pick-up flight test showed that the capability of the product meet the requirement.

Semiconductor devices incorporating multilayer interference regions

DOEpatents

Biefeld, Robert M.; Drummond, Timothy J.; Gourley, Paul L.; Zipperian, Thomas E.

1990-01-01

A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration.

Variable temperature semiconductor film deposition

DOEpatents

Li, X.; Sheldon, P.

1998-01-27

A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

Variable temperature semiconductor film deposition

DOEpatents

Li, Xiaonan; Sheldon, Peter

1998-01-01

A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

A room-temperature magnetic semiconductor from a ferromagnetic metallic glass

NASA Astrophysics Data System (ADS)

Liu, Wenjian; Zhang, Hongxia; Shi, Jin-An; Wang, Zhongchang; Song, Cheng; Wang, Xiangrong; Lu, Siyuan; Zhou, Xiangjun; Gu, Lin; Louzguine-Luzgin, Dmitri V.; Chen, Mingwei; Yao, Kefu; Chen, Na

2016-12-01

Emerging for future spintronic/electronic applications, magnetic semiconductors have stimulated intense interest due to their promises for new functionalities and device concepts. So far, the so-called diluted magnetic semiconductors attract many attentions, yet it remains challenging to increase their Curie temperatures above room temperature, particularly those based on III-V semiconductors. In contrast to the concept of doping magnetic elements into conventional semiconductors to make diluted magnetic semiconductors, here we propose to oxidize originally ferromagnetic metals/alloys to form new species of magnetic semiconductors. We introduce oxygen into a ferromagnetic metallic glass to form a Co28.6Fe12.4Ta4.3B8.7O46 magnetic semiconductor with a Curie temperature above 600 K. The demonstration of p-n heterojunctions and electric field control of the room-temperature ferromagnetism in this material reflects its p-type semiconducting character, with a mobility of 0.1 cm2 V-1 s-1. Our findings may pave a new way to realize high Curie temperature magnetic semiconductors with unusual multifunctionalities.

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Science.gov Websites

SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing (ERC ) ** Bringing Sustainability to Semiconductor Manufacturing ** A multi-university research center leading the way to environmentally friendly semiconductor manufacturing, sponsored by the Semiconductor Research

Semiconductor devices incorporating multilayer interference regions

DOEpatents

Biefeld, R.M.; Drummond, T.J.; Gourley, P.L.; Zipperian, T.E.

1987-08-31

A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration. 8 figs.

Method of making silicon on insalator material using oxygen implantation

DOEpatents

Hite, Larry R.; Houston, Ted; Matloubian, Mishel

1989-01-01

The described embodiments of the present invention provide a semiconductor on insulator structure providing a semiconductor layer less susceptible to single event upset errors (SEU) due to radiation. The semiconductor layer is formed by implanting ions which form an insulating layer beneath the surface of a crystalline semiconductor substrate. The remaining crystalline semiconductor layer above the insulating layer provides nucleation sites for forming a crystalline semiconductor layer above the insulating layer. The damage caused by implantation of the ions for forming an insulating layer is left unannealed before formation of the semiconductor layer by epitaxial growth. The epitaxial layer, thus formed, provides superior characteristics for prevention of SEU errors, in that the carrier lifetime within the epitaxial layer, thus formed, is less than the carrier lifetime in epitaxial layers formed on annealed material while providing adequate semiconductor characteristics.

Transient inactivation of the paraventricular nucleus of the thalamus enhances cue-induced reinstatement in goal-trackers, but not sign-trackers.

PubMed

Kuhn, Brittany N; Klumpner, Marin S; Covelo, Ignacio R; Campus, Paolo; Flagel, Shelly B

2018-04-01

The paraventricular nucleus of the thalamus (PVT) has been shown to mediate cue-motivated behaviors, such as sign- and goal-tracking, as well as reinstatement of drug-seeking behavior. However, the role of the PVT in mediating individual variation in cue-induced drug-seeking behavior remains unknown. This study aimed to determine if inactivation of the PVT differentially mediates cue-induced drug-seeking behavior in sign-trackers and goal-trackers. Rats were characterized as sign-trackers (STs) or goal-trackers (GTs) based on their Pavlovian conditioned approach behavior. Rats were then exposed to 15 days of cocaine self-administration, followed by a 2-week forced abstinence period and then extinction training. Rats then underwent tests for cue-induced reinstatement and general locomotor activity, prior to which they received an infusion of either saline (control) or baclofen/muscimol (B/M) to inactivate the PVT. Relative to control animals of the same phenotype, GTs show a robust increase in cue-induced drug-seeking behavior following PVT inactivation, whereas the behavior of STs was not affected. PVT inactivation did not affect locomotor activity in either phenotype. In GTs, the PVT appears to inhibit the expression of drug-seeking, presumably by attenuating the incentive value of the drug cue. Thus, inactivation of the PVT releases this inhibition in GTs, resulting in an increase in cue-induced drug-seeking behavior. PVT inactivation did not affect cue-induced drug-seeking behavior in STs, suggesting that the role of the PVT in encoding the incentive motivational value of drug cues differs between STs and GTs.

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed Central

El-Amrawy, Fatema

2015-01-01

Objectives The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Methods Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. Results The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. Conclusions The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure. PMID:26618039

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed

El-Amrawy, Fatema; Nounou, Mohamed Ismail

2015-10-01

The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure.

Into the deep: Evaluation of SourceTracker for assessment of faecal contamination of coastal waters.

PubMed

Henry, Rebekah; Schang, Christelle; Coutts, Scott; Kolotelo, Peter; Prosser, Toby; Crosbie, Nick; Grant, Trish; Cottam, Darren; O'Brien, Peter; Deletic, Ana; McCarthy, David

2016-04-15

Faecal contamination of recreational waters is an increasing global health concern. Tracing the source of the contaminant is a vital step towards mitigation and disease prevention. Total 16S rRNA amplicon data for a specific environment (faeces, water, soil) and computational tools such as the Markov-Chain Monte Carlo based SourceTracker can be applied to microbial source tracking (MST) and attribution studies. The current study applied artificial and in-laboratory derived bacterial communities to define the potential and limitations associated with the use of SourceTracker, prior to its application for faecal source tracking at three recreational beaches near Port Phillip Bay (Victoria, Australia). The results demonstrated that at minimum multiple model runs of the SourceTracker modelling tool (i.e. technical replicates) were required to identify potential false positive predictions. The calculation of relative standard deviations (RSDs) for each attributed source improved overall predictive confidence in the results. In general, default parameter settings provided high sensitivity, specificity, accuracy and precision. Application of SourceTracker to recreational beach samples identified treated effluent as major source of human-derived faecal contamination, present in 69% of samples. Site-specific sources, such as raw sewage, stormwater and bacterial populations associated with the Yarra River estuary were also identified. Rainfall and associated sand resuspension at each location correlated with observed human faecal indicators. The results of the optimised SourceTracker analysis suggests that local sources of contamination have the greatest effect on recreational coastal water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Parallel Worm Tracker: A Platform for Measuring Average Speed and Drug-Induced Paralysis in Nematodes

PubMed Central

Ramot, Daniel; Johnson, Brandon E.; Berry, Tommie L.; Carnell, Lucinda; Goodman, Miriam B.

2008-01-01

Background Caenorhabditis elegans locomotion is a simple behavior that has been widely used to dissect genetic components of behavior, synaptic transmission, and muscle function. Many of the paradigms that have been created to study C. elegans locomotion rely on qualitative experimenter observation. Here we report the implementation of an automated tracking system developed to quantify the locomotion of multiple individual worms in parallel. Methodology/Principal Findings Our tracking system generates a consistent measurement of locomotion that allows direct comparison of results across experiments and experimenters and provides a standard method to share data between laboratories. The tracker utilizes a video camera attached to a zoom lens and a software package implemented in MATLAB®. We demonstrate several proof-of-principle applications for the tracker including measuring speed in the absence and presence of food and in the presence of serotonin. We further use the tracker to automatically quantify the time course of paralysis of worms exposed to aldicarb and levamisole and show that tracker performance compares favorably to data generated using a hand-scored metric. Conclusions/Signficance Although this is not the first automated tracking system developed to measure C. elegans locomotion, our tracking software package is freely available and provides a simple interface that includes tools for rapid data collection and analysis. By contrast with other tools, it is not dependent on a specific set of hardware. We propose that the tracker may be used for a broad range of additional worm locomotion applications including genetic and chemical screening. PMID:18493300

Individual differences in food cue responsivity are associated with acute and repeated cocaine-induced vocalizations, but not cue-induced vocalizations.

PubMed

Tripi, Jordan A; Dent, Micheal L; Meyer, Paul J

2017-02-01

Individuals prone to attribute incentive salience to food-associated stimuli ("cues") are also more sensitive to cues during drug seeking and drug taking. This may be due in part to a difference in sensitivity to the affective or other stimulus properties of the drug. In rats, these properties are associated with 50-kHz ultrasonic vocalizations (USVs), in that they are elicited during putative positive affective and motivational states, including in response to drugs of abuse. We sought to determine whether individual differences in the tendency to attribute incentive salience to a food cue (as measured by approach) were associated with differences in cocaine-induced USVs. We also tested whether the food cue would elicit USVs and if this response was related to approach to the food cue. In experiment 1, rats underwent Pavlovian conditioned approach (PavCA) training where they learned to associate a cue (an illuminated lever) with the delivery of a food pellet into a food cup. Subjects were categorized based on their approach to the cue ("sign-trackers") or to the food cup ("goal-trackers"). Rats subsequently underwent nine testing days in which they were given saline or cocaine (10 mg/kg i.p) and placed into a locomotor chamber. In experiment 2, rats were first tested in the locomotor chambers for one saline-treated day followed by one cocaine-treated day and then trained in PavCA. USVs were recorded from a subset of individuals during the last day of PavCA to determine if the food cue would elicit USVs. Sign-trackers produced 5-24 times more cocaine-induced 50 kHz USVs compared to goal-trackers for all days of experiment 1, and this response sensitized with repeated cocaine, only in sign-trackers. Similarly in experiment 2, individuals that produced the most cocaine-induced USVs on a single exposure also showed the greatest tendency to sign-track during PavCA. Lastly, while sign-trackers produced more USVs during PavCA generally, the cue itself did not elicit additional USVs in sign- or goal-trackers. These results indicate a robust and consistent relationship between approach to a food cue and cocaine-induced USV production. Thus, these USVs may index the neurobiological differences underlying the behavioral distinctions of sign- and goal-trackers.

Controlling the stoichiometry and doping of semiconductor materials

DOEpatents

Albin, David; Burst, James; Metzger, Wyatt; Duenow, Joel; Farrell, Stuart; Colegrove, Eric

2016-08-16

Methods for treating a semiconductor material are provided. According to an aspect of the invention, the method includes annealing the semiconductor material in the presence of a compound that includes a first element and a second element. The first element provides an overpressure to achieve a desired stoichiometry of the semiconductor material, and the second element provides a dopant to the semiconductor material.

ERC Membership/Boards

Science.gov Websites

SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing (ERC ) ** Bringing Sustainability to Semiconductor Manufacturing ** A multi-university research center leading the way to environmentally friendly semiconductor manufacturing, sponsored by the Semiconductor Research

Bi-Se doped with Cu, p-type semiconductor

DOEpatents

Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

2013-08-20

A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2006-09-05

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon [Pinole, CA; Bruchez, Jr., Marcel; Alivisatos, Paul [Oakland, CA

2004-03-02

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2005-08-09

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2002-01-01

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in he probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Back-side readout semiconductor photomultiplier

DOEpatents

Choong, Woon-Seng; Holland, Stephen E

2014-05-20

This disclosure provides systems, methods, and apparatus related to semiconductor photomultipliers. In one aspect, a device includes a p-type semiconductor substrate, the p-type semiconductor substrate having a first side and a second side, the first side of the p-type semiconductor substrate defining a recess, and the second side of the p-type semiconductor substrate being doped with n-type ions. A conductive material is disposed in the recess. A p-type epitaxial layer is disposed on the second side of the p-type semiconductor substrate. The p-type epitaxial layer includes a first region proximate the p-type semiconductor substrate, the first region being implanted with p-type ions at a higher doping level than the p-type epitaxial layer, and a second region disposed on the first region, the second region being doped with p-type ions at a higher doping level than the first region.

Bulk semiconducting scintillator device for radiation detection

DOEpatents

Stowe, Ashley C.; Burger, Arnold; Groza, Michael

2016-08-30

A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI.sub.2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.

Sintered silver joints via controlled topography of electronic packaging subcomponents

DOEpatents

Wereszczak, Andrew A.

2014-09-02

Disclosed are sintered silver bonded electronic package subcomponents and methods for making the same. Embodiments of the sintered silver bonded EPSs include topography modification of one or more metal surfaces of semiconductor devices bonded together by the sintered silver joint. The sintered silver bonded EPSs include a first semiconductor device having a first metal surface, the first metal surface having a modified topography that has been chemically etched, grit blasted, uniaxial ground and/or grid sliced connected to a second semiconductor device which may also include a first metal surface with a modified topography, a silver plating layer on the first metal surface of the first semiconductor device and a silver plating layer on the first metal surface of the second semiconductor device and a sintered silver joint between the silver plating layers of the first and second semiconductor devices which bonds the first semiconductor device to the second semiconductor device.

Semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Marcel; Alivisatos, Paul

2014-01-28

A semiconductor nanocrystal compound and probe are described. The compound is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with one or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. Also described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and treating materials with the probe.

Semiconductor nanocrystal probes for biological applications and process for making and using such probes

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

Weiss, Shimon; Bruchez, Marcel; Alivisatos, Paul A.

2016-12-27

A semiconductor nanocrystal compound and probe are described. The compound is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with onemore » or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. Also described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and treating materials with the probe.« less

Practical target location and accuracy indicator in digital close range photogrammetry using consumer grade cameras

NASA Astrophysics Data System (ADS)

Moriya, Gentaro; Chikatsu, Hirofumi

2011-07-01

Recently, pixel numbers and functions of consumer grade digital camera are amazingly increasing by modern semiconductor and digital technology, and there are many low-priced consumer grade digital cameras which have more than 10 mega pixels on the market in Japan. In these circumstances, digital photogrammetry using consumer grade cameras is enormously expected in various application fields. There is a large body of literature on calibration of consumer grade digital cameras and circular target location. Target location with subpixel accuracy had been investigated as a star tracker issue, and many target location algorithms have been carried out. It is widely accepted that the least squares models with ellipse fitting is the most accurate algorithm. However, there are still problems for efficient digital close range photogrammetry. These problems are reconfirmation of the target location algorithms with subpixel accuracy for consumer grade digital cameras, relationship between number of edge points along target boundary and accuracy, and an indicator for estimating the accuracy of normal digital close range photogrammetry using consumer grade cameras. With this motive, an empirical testing of several algorithms for target location with subpixel accuracy and an indicator for estimating the accuracy are investigated in this paper using real data which were acquired indoors using 7 consumer grade digital cameras which have 7.2 mega pixels to 14.7 mega pixels.

Semiconductor electrode with improved photostability characteristics

DOEpatents

Frank, A.J.

1985-02-19

An electrode is described for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode consists of a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

Semiconductor electrode with improved photostability characteristics

DOEpatents

Frank, Arthur J.

1987-01-01

An electrode is disclosed for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode includes a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

Remote control radioactive-waste removal system uses modulated laser transmitter

NASA Technical Reports Server (NTRS)

Burcher, E. E.; Kopia, L. P.; Rowland, C. W.; Sinclair, A. R.

1971-01-01

Laser remote control system consists of transmitter, auto tracker, and receiver. Transmitter and tracker, packaged together and bore sighted, constitute control station, receiver is slave station. Model has five command channels and optical link operating range of 110 m.

Design of the forward straw tube tracker for the PANDA experiment

NASA Astrophysics Data System (ADS)

Smyrski, J.; Apostolou, A.; Biernat, J.; Czyżycki, W.; Filo, G.; Fioravanti, E.; Fiutowski, T.; Gianotti, P.; Idzik, M.; Korcyl, G.; Korcyl, K.; Lisowski, E.; Lisowski, F.; Płażek, J.; Przyborowski, D.; Przygoda, W.; Ritman, J.; Salabura, P.; Savrie, M.; Strzempek, P.; Swientek, K.; Wintz, P.; Wrońska, A.

2017-06-01

The design of the Forward Tracker for the Forward Spectrometer of the PANDA experiment is described. The tracker consists of 6 tracking stations, each comprising 4 planar double layers of straw tube detectors, and has a total material budget of only 2% X0. The straws are made self-supporting by a 1 bar over-pressure of the working gas mixture (Ar/CO2). This allows to use lightweight and compact rectangular support frames for the double layers and to split the frames into pairs of C-shaped half-frames for an easier installation on the beam line.

Enhanced online convolutional neural networks for object tracking

NASA Astrophysics Data System (ADS)

Zhang, Dengzhuo; Gao, Yun; Zhou, Hao; Li, Tianwen

2018-04-01

In recent several years, object tracking based on convolution neural network has gained more and more attention. The initialization and update of convolution filters can directly affect the precision of object tracking effective. In this paper, a novel object tracking via an enhanced online convolution neural network without offline training is proposed, which initializes the convolution filters by a k-means++ algorithm and updates the filters by an error back-propagation. The comparative experiments of 7 trackers on 15 challenging sequences showed that our tracker can perform better than other trackers in terms of AUC and precision.

Electrical production testing of the D0 Silicon microstrip tracker detector modules

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

D0, SMT Production Testing Group; /Fermilab

The D0 Silicon Microstrip Tracker (SMT) is the innermost system of the D0 detector in Run 2. It consists of 912 detector units, corresponding to 5 different types of assemblies, which add up to a system with 792,576 readout channels. The task entrusted to the Production Testing group was to thoroughly debug, test and grade each detector module before its installation in the tracker. This note describes the production testing sequence and the procedures by which the detector modules were electrically tested and characterized at the various stages of their assembly.

A laser-based eye-tracking system.

PubMed

Irie, Kenji; Wilson, Bruce A; Jones, Richard D; Bones, Philip J; Anderson, Tim J

2002-11-01

This paper reports on the development of a new eye-tracking system for noninvasive recording of eye movements. The eye tracker uses a flying-spot laser to selectively image landmarks on the eye and, subsequently, measure horizontal, vertical, and torsional eye movements. Considerable work was required to overcome the adverse effects of specular reflection of the flying-spot from the surface of the eye onto the sensing elements of the eye tracker. These effects have been largely overcome, and the eye-tracker has been used to document eye movement abnormalities, such as abnormal torsional pulsion of saccades, in the clinical setting.

Design of a cost-effective laser spot tracker

NASA Astrophysics Data System (ADS)

Artan, Göktuǧ Gencehan; Sari, Hüseyin

2017-05-01

One of the most important aspects of guided systems is detection. The most convenient detection in the sense of precision can be achieved with a laser spot tracker. This study deals with a military grade, high performance and cost-effective laser spot tracker for a guided system. The aim is to develop a high field of view system that will detect a laser spot from a distance of 3 kilometers in which the target is designated from 3 kilometers with a laser. The study basically consists of the system design, modeling, producing and the conducting performance tests of the whole system.

Low-Frequency Error Extraction and Compensation for Attitude Measurements from STECE Star Tracker

PubMed Central

Lai, Yuwang; Gu, Defeng; Liu, Junhong; Li, Wenping; Yi, Dongyun

2016-01-01

The low frequency errors (LFE) of star trackers are the most penalizing errors for high-accuracy satellite attitude determination. Two test star trackers- have been mounted on the Space Technology Experiment and Climate Exploration (STECE) satellite, a small satellite mission developed by China. To extract and compensate the LFE of the attitude measurements for the two test star trackers, a new approach, called Fourier analysis, combined with the Vondrak filter method (FAVF) is proposed in this paper. Firstly, the LFE of the two test star trackers’ attitude measurements are analyzed and extracted by the FAVF method. The remarkable orbital reproducibility features are found in both of the two test star trackers’ attitude measurements. Then, by using the reproducibility feature of the LFE, the two star trackers’ LFE patterns are estimated effectively. Finally, based on the actual LFE pattern results, this paper presents a new LFE compensation strategy. The validity and effectiveness of the proposed LFE compensation algorithm is demonstrated by the significant improvement in the consistency between the two test star trackers. The root mean square (RMS) of the relative Euler angle residuals are reduced from [27.95′′, 25.14′′, 82.43′′], 3σ to [16.12′′, 15.89′′, 53.27′′], 3σ. PMID:27754320

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

Argo, P.E.; DeLapp, D.; Sutherland, C.D.

TRACKER is an extension of a three-dimensional Hamiltonian raytrace code developed some thirty years ago by R. Michael Jones. Subsequent modifications to this code, which is commonly called the {open_quotes}Jones Code,{close_quotes} were documented by Jones and Stephensen (1975). TRACKER incorporates an interactive user`s interface, modern differential equation integrators, graphical outputs, homing algorithms, and the Ionospheric Conductivity and Electron Density (ICED) ionosphere. TRACKER predicts the three-dimensional paths of radio waves through model ionospheres by numerically integrating Hamilton`s equations, which are a differential expression of Fermat`s principle of least time. By using continuous models, the Hamiltonian method avoids false caustics and discontinuousmore » raypath properties often encountered in other raytracing methods. In addition to computing the raypath, TRACKER also calculates the group path (or pulse travel time), the phase path, the geometrical (or {open_quotes}real{close_quotes}) pathlength, and the Doppler shift (if the time variation of the ionosphere is explicitly included). Computational speed can be traded for accuracy by specifying the maximum allowable integration error per step in the integration. Only geometrical optics are included in the main raytrace code; no partial reflections or diffraction effects are taken into account. In addition, TRACKER does not lend itself to statistical descriptions of propagation -- it requires a deterministic model of the ionosphere.« less

EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes.

PubMed

Popelka, Stanislav; Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

2016-01-01

The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe.

EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes

PubMed Central

Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

2016-01-01

The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe. PMID:27087805

Experience from the in-flight calibration of the Extreme Ultraviolet Explorer (EUVE) and Upper Atmosphere Research Satellite (UARS) fixed head star trackers (FHSTs)

NASA Technical Reports Server (NTRS)

Lee, Michael

1995-01-01

Since the original post-launch calibration of the FHSTs (Fixed Head Star Trackers) on EUVE (Extreme Ultraviolet Explorer) and UARS (Upper Atmosphere Research Satellite), the Flight Dynamics task has continued to analyze the FHST performance. The algorithm used for inflight alignment of spacecraft sensors is described and the equations for the errors in the relative alignment for the simple 2 star tracker case are shown. Simulated data and real data are used to compute the covariance of the relative alignment errors. Several methods for correcting the alignment are compared and results analyzed. The specific problems seen on orbit with UARS and EUVE are then discussed. UARS has experienced anomalous tracker performance on an FHST resulting in continuous variation in apparent tracker alignment. On EUVE, the FHST residuals from the attitude determination algorithm showed a dependence on the direction of roll during survey mode. This dependence is traced back to time tagging errors and the original post launch alignment is found to be in error due to the impact of the time tagging errors on the alignment algorithm. The methods used by the FDF (Flight Dynamics Facility) to correct for these problems is described.

Could we do better? Behavioural tracking on recommended consumer health websites.

PubMed

Burkell, Jacquelyn; Fortier, Alexandre

2015-09-01

This study examines behavioural tracking practices on consumer health websites, contrasting tracking on sites recommended by information professionals with tracking on sites returned by Google. Two lists of consumer health websites were constructed: sites recommended by information professionals and sites returned by Google searches. Sites were divided into three groups according to source (Recommended-Only, Google-Only or both) and type (Government, Not-for-Profit or Commercial). Behavioural tracking practices on each website were documented using a protocol that detected cookies, Web beacons and Flash cookies. The presence and the number of trackers that collect personal information were contrasted across source and type of site; a second set of analyses specifically examined Advertising trackers. Recommended-Only sites show lower levels of tracking - especially tracking by advertisers - than do Google-Only sites or sites found through both sources. Government and Not-for-Profit sites have fewer trackers, particularly from advertisers, than do Commercial sites. Recommended sites, especially those from Government or Not-for-Profit organisations, present a lower privacy threat than sites returned by Google searches. Nonetheless, most recommended websites include some trackers, and half include at least one Advertising tracker. To protect patron privacy, information professionals should examine the tracking practices of the websites they recommend. © 2015 Health Libraries Group.

Radiation hardness and timing studies of a monolithic TowerJazz pixel design for the new ATLAS Inner Tracker

NASA Astrophysics Data System (ADS)

Riegel, C.; Backhaus, M.; Van Hoorne, J. W.; Kugathasan, T.; Musa, L.; Pernegger, H.; Riedler, P.; Schaefer, D.; Snoeys, W.; Wagner, W.

2017-01-01

A part of the upcoming HL-LHC upgrade of the ATLAS Detector is the construction of a new Inner Tracker. This upgrade opens new possibilities, but also presents challenges in terms of occupancy and radiation tolerance. For the pixel detector inside the inner tracker, hybrid modules containing passive silicon sensors and connected readout chips are presently used, but require expensive assembly techniques like fine-pitch bump bonding. Silicon devices fabricated in standard commercial CMOS technologies, which include part or all of the readout chain, are also investigated offering a reduced cost as they are cheaper per unit area than traditional silicon detectors. If they contain the full readout chain, as for a fully monolithic approach, there is no need for the expensive flip-chip assembly, resulting in a further cost reduction and material savings. In the outer pixel layers of the ATLAS Inner Tracker, the pixel sensors must withstand non-ionising energy losses of up to 1015 n/cm2 and offer a timing resolution of 25 ns or less. This paper presents test results obtained on a monolithic test chip, the TowerJazz 180nm Investigator, towards these specifications. The presented program of radiation hardness and timing studies has been launched to investigate this technology's potential for the new ATLAS Inner Tracker.

Promoting physical activity using a wearable activity tracker in college students: A cluster randomized controlled trial.

PubMed

Kim, Youngdeok; Lumpkin, Angela; Lochbaum, Marc; Stegemeier, Steven; Kitten, Karla

2018-08-01

This study examined the effects of utilizing a wearable activity tracker in a credit-based physical activity instructional program (PAIP) for promoting physical activity (PA) in college students. Fourteen PAIP courses in a large public university were randomly assigned into intervention (k = 7; n = 101) and control (k = 7; n = 86) groups. All courses focused on a core curriculum that covers basic exercise and behavioral science contents through lectures and activity sessions. A Misfit Flash activity tracker was provided to students in the intervention group. Objective PA assessments occurred at baseline, mid-, and end-of-semester during a 15-week academic semester. The control group showed a significant reduction in moderate- and vigorous-intensity PA (MVPA) minutes from baseline to the end-of-semester (P <.05), whereas the intervention group showed no changes in MVPA minutes over time. However, the intervention group also showed increased sedentary time and decreased time spent in light-intensity PA during the intervention period. Taken together, the present study found null effects of utilizing the wearable activity tracker in promoting PA in college students suggesting that intervention of primary using the wearable activity tracker as a behavior change strategy may not be effective to increase in PA in this setting.

Iterative learning-based decentralized adaptive tracker for large-scale systems: a digital redesign approach.

PubMed

Tsai, Jason Sheng-Hong; Du, Yan-Yi; Huang, Pei-Hsiang; Guo, Shu-Mei; Shieh, Leang-San; Chen, Yuhua

2011-07-01

In this paper, a digital redesign methodology of the iterative learning-based decentralized adaptive tracker is proposed to improve the dynamic performance of sampled-data linear large-scale control systems consisting of N interconnected multi-input multi-output subsystems, so that the system output will follow any trajectory which may not be presented by the analytic reference model initially. To overcome the interference of each sub-system and simplify the controller design, the proposed model reference decentralized adaptive control scheme constructs a decoupled well-designed reference model first. Then, according to the well-designed model, this paper develops a digital decentralized adaptive tracker based on the optimal analog control and prediction-based digital redesign technique for the sampled-data large-scale coupling system. In order to enhance the tracking performance of the digital tracker at specified sampling instants, we apply the iterative learning control (ILC) to train the control input via continual learning. As a result, the proposed iterative learning-based decentralized adaptive tracker not only has robust closed-loop decoupled property but also possesses good tracking performance at both transient and steady state. Besides, evolutionary programming is applied to search for a good learning gain to speed up the learning process of ILC. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Participatory Sensing Marine Debris: Current Trends and Future Opportunities

NASA Astrophysics Data System (ADS)

Jambeck, J.; Johnsen, K.

2016-02-01

The monitoring of litter and debris is challenging at the global scale because of spatial and temporal variability, disconnected local organizations and the use of paper and pen for documentation. The Marine Debris Tracker mobile app and citizen science program allows for the collection of global standardized data at a scale, speed and efficiency that was not previously possible. The app itself also serves as an outreach and education tool, creating an engaged participatory sensing instrument. This instrument is characterized by several aspects including range and frequency, accuracy and precision, accessibility, measurement dimensions, participant performance, and statistical analysis. Also, important to Marine Debris Tracker is open data and transparency. A web portal provides data that users have logged allowing immediate feedback to users and additional education opportunities. The engagement of users through a top tracker competition and social media keeps participants interested in the Marine Debris Tracker community. Over half a million items have been tracked globally, and maps provide both global and local distribution of data. The Marine Debris Tracker community and dataset continues to grow daily. We will present current usage and engagement, participatory sensing data distributions, choropleth maps of areas of active tracking, and discuss future technologies and platforms to expand data collection and conduct statistical analysis.

The influence of a consumer-wearable activity tracker on sedentary time and prolonged sedentary bouts: secondary analysis of a randomized controlled trial.

PubMed

Sloan, Robert A; Kim, Youngdeok; Sahasranaman, Aarti; Müller-Riemenschneider, Falk; Biddle, Stuart J H; Finkelstein, Eric A

2018-03-22

A recent meta-analysis surmised pedometers were a useful panacea to independently reduce sedentary time (ST). To further test and expand on this deduction, we analyzed the ability of a consumer-wearable activity tracker to reduce ST and prolonged sedentary bouts (PSB). We originally conducted a 12-month randomized control trial where 800 employees from 13 organizations were assigned to control, activity tracker, or one of two activity tracker plus incentive groups designed to increase step count. The primary outcome was accelerometer measured moderate-to-vigorous physical activity. We conducted a secondary analysis on accelerometer measured daily ST and PSB bouts. A general linear mixed model was used to examine changes in ST and prolonged sedentary bouts, followed by between-group pairwise comparisons. Regression analyses were conducted to examine the association of changes in step counts with ST and PSB. The changes in ST and PSB were not statistically significant and not different between the groups (P < 0.05). Increases in step counts were concomitantly associated with decreases in ST and PSB, regardless of intervention (P < 0.05). Caution should be taken when considering consumer-wearable activity trackers as a means to reduce sedentary behavior. Trial registration NCT01855776 Registered: August 8, 2012.

Evaluating the effectiveness of organisational-level strategies with or without an activity tracker to reduce office workers' sitting time: a cluster-randomised trial.

PubMed

Brakenridge, C L; Fjeldsoe, B S; Young, D C; Winkler, E A H; Dunstan, D W; Straker, L M; Healy, G N

2016-11-04

Office workers engage in high levels of sitting time. Effective, context-specific, and scalable strategies are needed to support widespread sitting reduction. This study aimed to evaluate organisational-support strategies alone or in combination with an activity tracker to reduce sitting in office workers. From one organisation, 153 desk-based office workers were cluster-randomised (by team) to organisational support only (e.g., manager support, emails; 'Group ORG', 9 teams, 87 participants), or organisational support plus LUMOback activity tracker ('Group ORG + Tracker', 9 teams, 66 participants). The waist-worn tracker provided real-time feedback and prompts on sitting and posture. ActivPAL3 monitors were used to ascertain primary outcomes (sitting time during work- and overall hours) and other activity outcomes: prolonged sitting time (≥30 min bouts), time between sitting bouts, standing time, stepping time, and number of steps. Health and work outcomes were assessed by questionnaire. Changes within each group (three- and 12 months) and differences between groups were analysed by linear mixed models. Missing data were multiply imputed. At baseline, participants (46 % women, 23-58 years) spent (mean ± SD) 74.3 ± 9.7 % of their workday sitting, 17.5 ± 8.3 % standing and 8.1 ± 2.7 % stepping. Significant (p < 0.05) reductions in sitting time (both work and overall) were observed within both groups, but only at 12 months. For secondary activity outcomes, Group ORG significantly improved in work prolonged sitting, time between sitting bouts and standing time, and overall prolonged sitting time (12 months), and in overall standing time (three- and 12 months); while Group ORG + Tracker, significantly improved in work prolonged sitting, standing, stepping and overall standing time (12 months). Adjusted for confounders, the only significant between-group differences were a greater stepping time and step count for Group ORG + Tracker relative to Group ORG (+20.6 min/16 h day, 95 % CI: 3.1, 38.1, p = 0.021; +846.5steps/16 h day, 95 % CI: 67.8, 1625.2, p = 0.033) at 12 months. Observed changes in health and work outcomes were small and not statistically significant. Organisational-support strategies with or without an activity tracker resulted in improvements in sitting, prolonged sitting and standing; adding a tracker enhanced stepping changes. Improvements were most evident at 12 months, suggesting the organisational-support strategies may have taken time to embed within the organisation. Australian New Zealand Clinical Trial Registry: ACTRN12614000252617 . Registered 10 March 2014.

A room-temperature magnetic semiconductor from a ferromagnetic metallic glass.

PubMed

Liu, Wenjian; Zhang, Hongxia; Shi, Jin-An; Wang, Zhongchang; Song, Cheng; Wang, Xiangrong; Lu, Siyuan; Zhou, Xiangjun; Gu, Lin; Louzguine-Luzgin, Dmitri V; Chen, Mingwei; Yao, Kefu; Chen, Na

2016-12-08

Emerging for future spintronic/electronic applications, magnetic semiconductors have stimulated intense interest due to their promises for new functionalities and device concepts. So far, the so-called diluted magnetic semiconductors attract many attentions, yet it remains challenging to increase their Curie temperatures above room temperature, particularly those based on III-V semiconductors. In contrast to the concept of doping magnetic elements into conventional semiconductors to make diluted magnetic semiconductors, here we propose to oxidize originally ferromagnetic metals/alloys to form new species of magnetic semiconductors. We introduce oxygen into a ferromagnetic metallic glass to form a Co 28.6 Fe 12.4 Ta 4.3 B 8.7 O 46 magnetic semiconductor with a Curie temperature above 600 K. The demonstration of p-n heterojunctions and electric field control of the room-temperature ferromagnetism in this material reflects its p-type semiconducting character, with a mobility of 0.1 cm 2  V -1  s -1 . Our findings may pave a new way to realize high Curie temperature magnetic semiconductors with unusual multifunctionalities.

A room-temperature magnetic semiconductor from a ferromagnetic metallic glass

PubMed Central

Liu, Wenjian; Zhang, Hongxia; Shi, Jin-an; Wang, Zhongchang; Song, Cheng; Wang, Xiangrong; Lu, Siyuan; Zhou, Xiangjun; Gu, Lin; Louzguine-Luzgin, Dmitri V.; Chen, Mingwei; Yao, Kefu; Chen, Na

2016-01-01

Emerging for future spintronic/electronic applications, magnetic semiconductors have stimulated intense interest due to their promises for new functionalities and device concepts. So far, the so-called diluted magnetic semiconductors attract many attentions, yet it remains challenging to increase their Curie temperatures above room temperature, particularly those based on III–V semiconductors. In contrast to the concept of doping magnetic elements into conventional semiconductors to make diluted magnetic semiconductors, here we propose to oxidize originally ferromagnetic metals/alloys to form new species of magnetic semiconductors. We introduce oxygen into a ferromagnetic metallic glass to form a Co28.6Fe12.4Ta4.3B8.7O46 magnetic semiconductor with a Curie temperature above 600 K. The demonstration of p–n heterojunctions and electric field control of the room-temperature ferromagnetism in this material reflects its p-type semiconducting character, with a mobility of 0.1 cm2 V−1 s−1. Our findings may pave a new way to realize high Curie temperature magnetic semiconductors with unusual multifunctionalities. PMID:27929059

Where the chips fall: environmental health in the semiconductor industry.

PubMed

Chepesiuk, R

1999-09-01

Three recent lawsuits are focusing public attention on the environmental and occupational health effects of the world's largest and fastest growing manufacturing sector-the $150 billion semiconductor industry. The suits allege that exposure to toxic chemicals in semiconductor manufacturing plants led to adverse health effects such as miscarriage and cancer among workers. To manufacture computer components, the semiconductor industry uses large amounts of hazardous chemicals including hydrochloric acid, toxic metals and gases, and volatile solvents. Little is known about the long-term health consequences of exposure to chemicals by semiconductor workers. According to industry critics, the semiconductor industry also adversely impacts the environment, causing groundwater and air pollution and generating toxic waste as a by-product of the semiconductor manufacturing process. In contrast, the U.S. Bureau of Statistics shows the semiconductor industry as having a worker illness rate of about one-third of the average of all manufacturers, and advocates defend the industry, pointing to recent research collaborations and product replacement as proof that semiconductor manufacturers adequately protect both their employees and the environment.

Where the chips fall: environmental health in the semiconductor industry.

PubMed Central

Chepesiuk, R

1999-01-01

Three recent lawsuits are focusing public attention on the environmental and occupational health effects of the world's largest and fastest growing manufacturing sector-the $150 billion semiconductor industry. The suits allege that exposure to toxic chemicals in semiconductor manufacturing plants led to adverse health effects such as miscarriage and cancer among workers. To manufacture computer components, the semiconductor industry uses large amounts of hazardous chemicals including hydrochloric acid, toxic metals and gases, and volatile solvents. Little is known about the long-term health consequences of exposure to chemicals by semiconductor workers. According to industry critics, the semiconductor industry also adversely impacts the environment, causing groundwater and air pollution and generating toxic waste as a by-product of the semiconductor manufacturing process. In contrast, the U.S. Bureau of Statistics shows the semiconductor industry as having a worker illness rate of about one-third of the average of all manufacturers, and advocates defend the industry, pointing to recent research collaborations and product replacement as proof that semiconductor manufacturers adequately protect both their employees and the environment. PMID:10464084

Semiconductor nanocrystal-based phagokinetic tracking

DOEpatents

Alivisatos, A Paul; Larabell, Carolyn A; Parak, Wolfgang J; Le Gros, Mark; Boudreau, Rosanne

2014-11-18

Methods for determining metabolic properties of living cells through the uptake of semiconductor nanocrystals by cells. Generally the methods require a layer of neutral or hydrophilic semiconductor nanocrystals and a layer of cells seeded onto a culture surface and changes in the layer of semiconductor nanocrystals are detected. The observed changes made to the layer of semiconductor nanocrystals can be correlated to such metabolic properties as metastatic potential, cell motility or migration.

Semiconductor devices having a recessed electrode structure

DOEpatents

Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

2015-05-26

An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

Diode having trenches in a semiconductor region

DOEpatents

Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

2016-03-22

An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

Solid state radiative heat pump

DOEpatents

Berdahl, P.H.

1984-09-28

A solid state radiative heat pump operable at room temperature (300 K) utilizes a semiconductor having a gap energy in the range of 0.03-0.25 eV and operated reversibly to produce an excess or deficit of change carriers as compared equilibrium. In one form of the invention an infrared semiconductor photodiode is used, with forward or reverse bias, to emit an excess or deficit of infrared radiation. In another form of the invention, a homogenous semiconductor is subjected to orthogonal magnetic and electric fields to emit an excess or deficit of infrared radiation. Three methods of enhancing transmission of radiation the active surface of the semiconductor are disclosed. In one method, an anti-refection layer is coated into the active surface of the semiconductor, the anti-reflection layer having an index of refraction equal to the square root of that of the semiconductor. In the second method, a passive layer is speaced trom the active surface of the semiconductor by a submicron vacuum gap, the passive layer having an index of refractive equal to that of the semiconductor. In the third method, a coupler with a paraboloid reflecting surface surface is in contact with the active surface of the semiconductor, the coupler having an index of refraction about the same as that of the semiconductor.

Wafer-fused semiconductor radiation detector

DOEpatents

Lee, Edwin Y.; James, Ralph B.

2002-01-01

Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

Individual Differences in the Attribution of Incentive Salience to a Pavlovian Alcohol Cue

PubMed Central

Villaruel, Franz R.; Chaudhri, Nadia

2016-01-01

Individual differences exist in the attribution of incentive salience to conditioned stimuli associated with food. Here, we investigated whether individual differences also manifested with a Pavlovian alcohol conditioned stimulus (CS). We compiled data from five experiments that used a Pavlovian autoshaping paradigm and tests of conditioned reinforcement. In all experiments, male, Long-Evans rats with unrestricted access to food and water were acclimated to 15% ethanol. Next, rats received Pavlovian autoshaping training, in which a 10 s presentation of a retractable lever served as the CS and 0.2 mL of 15% ethanol served as the unconditioned stimulus (US). Finally, rats underwent conditioned reinforcement tests in which nose-pokes to an active aperture led to brief presentations of the lever-CS, but nose-pokes to an inactive aperture had no consequence. Rats were categorized as sign-trackers, goal-trackers and intermediates based on a response bias score that reflected their tendencies to sign-track or goal-track at different times during training. We found that distinct groups of rats either consistently interacted with the lever-CS (“sign-trackers”) or routinely approached the port during the lever-CS (“goal-trackers”) across a majority of the training sessions. However, some individuals (“shifted sign-trackers”) with an early tendency to goal-track later shifted to comparable asymptotic levels of sign-tracking as the group identified as sign-trackers. The lever-CS functioned as a conditioned reinforcer for sign-trackers and shifted sign-trackers, but not for goal-trackers. These results provide evidence of robust individual differences in the extent to which a Pavlovian alcohol cue gains incentive salience and functions as a conditioned reinforcer. PMID:28082877

78 FR 21344 - Grant of Authority for Subzone Status, Hemlock Semiconductor Corporation, (Polysilicon), Hemlock...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-10

... Status, Hemlock Semiconductor Corporation, (Polysilicon), Hemlock, Michigan Pursuant to its authority... polysilicon manufacturing facility of Hemlock Semiconductor Corporation, located in Hemlock, Michigan (FTZ... manufacturing of polysilicon at the facility of Hemlock Semiconductor Corporation, located in Hemlock, Michigan...

Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors

NASA Astrophysics Data System (ADS)

Biyikli, Necmi; Haider, Ali

2017-09-01

In this paper, we present the progress in the growth of nanoscale semiconductors grown via atomic layer deposition (ALD). After the adoption by semiconductor chip industry, ALD became a widespread tool to grow functional films and conformal ultra-thin coatings for various applications. Based on self-limiting and ligand-exchange-based surface reactions, ALD enabled the low-temperature growth of nanoscale dielectric, metal, and semiconductor materials. Being able to deposit wafer-scale uniform semiconductor films at relatively low-temperatures, with sub-monolayer thickness control and ultimate conformality, makes ALD attractive for semiconductor device applications. Towards this end, precursors and low-temperature growth recipes are developed to deposit crystalline thin films for compound and elemental semiconductors. Conventional thermal ALD as well as plasma-assisted and radical-enhanced techniques have been exploited to achieve device-compatible film quality. Metal-oxides, III-nitrides, sulfides, and selenides are among the most popular semiconductor material families studied via ALD technology. Besides thin films, ALD can grow nanostructured semiconductors as well using either template-assisted growth methods or bottom-up controlled nucleation mechanisms. Among the demonstrated semiconductor nanostructures are nanoparticles, nano/quantum-dots, nanowires, nanotubes, nanofibers, nanopillars, hollow and core-shell versions of the afore-mentioned nanostructures, and 2D materials including transition metal dichalcogenides and graphene. ALD-grown nanoscale semiconductor materials find applications in a vast amount of applications including functional coatings, catalysis and photocatalysis, renewable energy conversion and storage, chemical sensing, opto-electronics, and flexible electronics. In this review, we give an overview of the current state-of-the-art in ALD-based nanoscale semiconductor research including the already demonstrated and future applications.

Semiconductor assisted metal deposition for nanolithography applications

DOEpatents

Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

2001-01-01

An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

Semiconductor assisted metal deposition for nanolithography applications

DOEpatents

Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

2002-01-01

An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

Electrochemical characterization of bilayer lipid membrane-semiconductor junctions

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

Zhao, Xiao Kang; Baral, S.; Fendler, J.H.

Three different systems of glyceryl monooleate (GMO), bilayer lipid membrane (BLM) supported semiconductor particles have been prepared and characterized. A single composition of particulate semiconductor deposited only on one side of the BLM constituted system A, two different compositions of particulate semiconductors sequentially deposited on the same side of the BLM represented system B, and two different compositions of particulate semiconductors deposited on the opposite sides of the BLM made up system C.

78 FR 18563 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

... Tracker (SPOT) System; OMB Control Number 0704-0460. Needs and Uses: In accordance with section 861 of... data into the Synchronized Predeployment and Operational Tracker (SPOT) System before deployment... designated the SPOT as the joint Web- based database to assist the Combatant Commander (CCDR) in maintaining...

Oregon regional intelligent transportation systems (ITS) integration program. Final phase II report

DOT National Transportation Integrated Search

2002-07-12

The purpose of the Transit Tracker evaluation is to collect and analyze data related to a change in bus riders behaviors and perceptions of service and security as a result of the Transit Tracker information displays. Four measures of effectivenes...

Oregon regional intelligent transportation systems (ITS) integration program. Final phase III report, transit tracker information displays

DOT National Transportation Integrated Search

2003-11-14

Transit Tracker uses global positioning system (GPS) technology to track how far a bus is along its scheduled route. This document presents the evaluation strategies and objectives, the data collection methodologies, and the results of the evaluation...

46 CFR 183.360 - Semiconductor rectifier systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Semiconductor rectifier systems. 183.360 Section 183.360... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents...

Semiconductors: A 21st Century Social Studies Topic.

ERIC Educational Resources Information Center

Sunal, Cynthia

2000-01-01

Addresses the reasons for exploring semiconductor technology and organic semiconductors in schools for either middle school or secondary students in an interdisciplinary social studies and science environment. Provides background information on transistors and semiconductors. Offers three social studies lessons and related science lessons if an…

46 CFR 183.360 - Semiconductor rectifier systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Semiconductor rectifier systems. 183.360 Section 183.360... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents...

Semiconductor photoelectrochemistry

NASA Technical Reports Server (NTRS)

Buoncristiani, A. M.; Byvik, C. E.

1983-01-01

Semiconductor photoelectrochemical reactions are investigated. A model of the charge transport processes in the semiconductor, based on semiconductor device theory, is presented. It incorporates the nonlinear processes characterizing the diffusion and reaction of charge carriers in the semiconductor. The model is used to study conditions limiting useful energy conversion, specifically the saturation of current flow due to high light intensity. Numerical results describing charge distributions in the semiconductor and its effects on the electrolyte are obtained. Experimental results include: an estimate rate at which a semiconductor photoelectrode is capable of converting electromagnetic energy into chemical energy; the effect of cell temperature on the efficiency; a method for determining the point of zero zeta potential for macroscopic semiconductor samples; a technique using platinized titanium dioxide powders and ultraviolet radiation to produce chlorine, bromine, and iodine from solutions containing their respective ions; the photoelectrochemical properties of a class of layered compounds called transition metal thiophosphates; and a technique used to produce high conversion efficiency from laser radiation to chemical energy.

A post-processing algorithm for time domain pitch trackers

NASA Astrophysics Data System (ADS)

Specker, P.

1983-01-01

This paper describes a powerful post-processing algorithm for time-domain pitch trackers. On two successive passes, the post-processing algorithm eliminates errors produced during a first pass by a time-domain pitch tracker. During the second pass, incorrect pitch values are detected as outliers by computing the distribution of values over a sliding 80 msec window. During the third pass (based on artificial intelligence techniques), remaining pitch pulses are used as anchor points to reconstruct the pitch train from the original waveform. The algorithm produced a decrease in the error rate from 21% obtained with the original time domain pitch tracker to 2% for isolated words and sentences produced in an office environment by 3 male and 3 female talkers. In a noisy computer room errors decreased from 52% to 2.9% for the same stimuli produced by 2 male talkers. The algorithm is efficient, accurate, and resistant to noise. The fundamental frequency micro-structure is tracked sufficiently well to be used in extracting phonetic features in a feature-based recognition system.

ASME B89.4.19 Performance Evaluation Tests and Geometric Misalignments in Laser Trackers

PubMed Central

Muralikrishnan, B.; Sawyer, D.; Blackburn, C.; Phillips, S.; Borchardt, B.; Estler, W. T.

2009-01-01

Small and unintended offsets, tilts, and eccentricity of the mechanical and optical components in laser trackers introduce systematic errors in the measured spherical coordinates (angles and range readings) and possibly in the calculated lengths of reference artifacts. It is desirable that the tests described in the ASME B89.4.19 Standard [1] be sensitive to these geometric misalignments so that any resulting systematic errors are identified during performance evaluation. In this paper, we present some analysis, using error models and numerical simulation, of the sensitivity of the length measurement system tests and two-face system tests in the B89.4.19 Standard to misalignments in laser trackers. We highlight key attributes of the testing strategy adopted in the Standard and propose new length measurement system tests that demonstrate improved sensitivity to some misalignments. Experimental results with a tracker that is not properly error corrected for the effects of the misalignments validate claims regarding the proposed new length tests. PMID:27504211

Real-Time Visual Tracking through Fusion Features

PubMed Central

Ruan, Yang; Wei, Zhenzhong

2016-01-01

Due to their high-speed, correlation filters for object tracking have begun to receive increasing attention. Traditional object trackers based on correlation filters typically use a single type of feature. In this paper, we attempt to integrate multiple feature types to improve the performance, and we propose a new DD-HOG fusion feature that consists of discriminative descriptors (DDs) and histograms of oriented gradients (HOG). However, fusion features as multi-vector descriptors cannot be directly used in prior correlation filters. To overcome this difficulty, we propose a multi-vector correlation filter (MVCF) that can directly convolve with a multi-vector descriptor to obtain a single-channel response that indicates the location of an object. Experiments on the CVPR2013 tracking benchmark with the evaluation of state-of-the-art trackers show the effectiveness and speed of the proposed method. Moreover, we show that our MVCF tracker, which uses the DD-HOG descriptor, outperforms the structure-preserving object tracker (SPOT) in multi-object tracking because of its high-speed and ability to address heavy occlusion. PMID:27347951

Kernelized correlation tracking with long-term motion cues

NASA Astrophysics Data System (ADS)

Lv, Yunqiu; Liu, Kai; Cheng, Fei

2018-04-01

Robust object tracking is a challenging task in computer vision due to interruptions such as deformation, fast motion and especially, occlusion of tracked object. When occlusions occur, image data will be unreliable and is insufficient for the tracker to depict the object of interest. Therefore, most trackers are prone to fail under occlusion. In this paper, an occlusion judgement and handling method based on segmentation of the target is proposed. If the target is occluded, the speed and direction of it must be different from the objects occluding it. Hence, the value of motion features are emphasized. Considering the efficiency and robustness of Kernelized Correlation Filter Tracking (KCF), it is adopted as a pre-tracker to obtain a predicted position of the target. By analyzing long-term motion cues of objects around this position, the tracked object is labelled. Hence, occlusion could be detected easily. Experimental results suggest that our tracker achieves a favorable performance and effectively handles occlusion and drifting problems.

Action-Driven Visual Object Tracking With Deep Reinforcement Learning.

PubMed

Yun, Sangdoo; Choi, Jongwon; Yoo, Youngjoon; Yun, Kimin; Choi, Jin Young

2018-06-01

In this paper, we propose an efficient visual tracker, which directly captures a bounding box containing the target object in a video by means of sequential actions learned using deep neural networks. The proposed deep neural network to control tracking actions is pretrained using various training video sequences and fine-tuned during actual tracking for online adaptation to a change of target and background. The pretraining is done by utilizing deep reinforcement learning (RL) as well as supervised learning. The use of RL enables even partially labeled data to be successfully utilized for semisupervised learning. Through the evaluation of the object tracking benchmark data set, the proposed tracker is validated to achieve a competitive performance at three times the speed of existing deep network-based trackers. The fast version of the proposed method, which operates in real time on graphics processing unit, outperforms the state-of-the-art real-time trackers with an accuracy improvement of more than 8%.

"Sturdy as a house with four windows," the star tracker of the future

NASA Astrophysics Data System (ADS)

Duivenvoorde, Tom; Leijtens, Johan; van der Heide, Erik J.

2017-11-01

Ongoing miniaturization of spacecraft demands the reduction in size of Attitude and Orbit Control Systems (AOCS). Therefore TNO has created a new design of a multi aperture, high performance, and miniaturized star tracker. The innovative design incorporates the latest developments in camera technology, attitude calculation and mechanical design into a system with 5 arc seconds accuracy, making the system usable for many applications. In this paper the results are presented of the system design and analysis, as well as the performance predictions for the Multi Aperture Baffled Star Tracker (MABS). The highly integrated system consists of multiple apertures without the need for external baffles, resulting in major advantages in mass, volume, alignment with the spacecraft and relative aperture stability. In the analysis part of this paper, the thermal and mechanical stability are discussed. In the final part the simulation results will be described that have lead to the predicted accuracy of the star tracker system and a peek into the future of attitude sensors is given.

Internal alignment and position resolution of the silicon tracker of DAMPE determined with orbit data

NASA Astrophysics Data System (ADS)

Tykhonov, A.; Ambrosi, G.; Asfandiyarov, R.; Azzarello, P.; Bernardini, P.; Bertucci, B.; Bolognini, A.; Cadoux, F.; D'Amone, A.; De Benedittis, A.; De Mitri, I.; Di Santo, M.; Dong, Y. F.; Duranti, M.; D'Urso, D.; Fan, R. R.; Fusco, P.; Gallo, V.; Gao, M.; Gargano, F.; Garrappa, S.; Gong, K.; Ionica, M.; La Marra, D.; Lei, S. J.; Li, X.; Loparco, F.; Marsella, G.; Mazziotta, M. N.; Peng, W. X.; Qiao, R.; Salinas, M. M.; Surdo, A.; Vagelli, V.; Vitillo, S.; Wang, H. Y.; Wang, J. Z.; Wang, Z. M.; Wu, D.; Wu, X.; Zhang, F.; Zhang, J. Y.; Zhao, H.; Zimmer, S.

2018-06-01

The DArk Matter Particle Explorer (DAMPE) is a space-borne particle detector designed to probe electrons and gamma-rays in the few GeV to 10 TeV energy range, as well as cosmic-ray proton and nuclei components between 10 GeV and 100 TeV. The silicon-tungsten tracker-converter is a crucial component of DAMPE. It allows the direction of incoming photons converting into electron-positron pairs to be estimated, and the trajectory and charge (Z) of cosmic-ray particles to be identified. It consists of 768 silicon micro-strip sensors assembled in 6 double layers with a total active area of 6.6 m2. Silicon planes are interleaved with three layers of tungsten plates, resulting in about one radiation length of material in the tracker. Internal alignment parameters of the tracker have been determined on orbit, with non-showering protons and helium nuclei. We describe the alignment procedure and present the position resolution and alignment stability measurements.

Method of Promoting Single Crystal Growth During Melt Growth of Semiconductors

NASA Technical Reports Server (NTRS)

Su, Ching-Hua (Inventor)

2013-01-01

The method of the invention promotes single crystal growth during fabrication of melt growth semiconductors. A growth ampoule and its tip have a semiconductor source material placed therein. The growth ampoule is placed in a first thermal environment that raises the temperature of the semiconductor source material to its liquidus temperature. The growth ampoule is then transitioned to a second thermal environment that causes the semiconductor source material in the growth ampoule's tip to attain a temperature that is below the semiconductor source material's solidus temperature. The growth ampoule so-transitioned is then mechanically perturbed to induce single crystal growth at the growth ampoule's tip.

Will Future Measurement Needs of the Semiconductor Industry Be Met?

PubMed

Bennett, Herbert S

2007-01-01

We discuss the ability of the nation's measurement system to meet future metrology needs of the semiconductor industry. Lacking an acceptable metric for assessing the health of metrology for the semiconductor industry, we identify a limited set of unmet measurement needs. Assuming that this set of needs may serve as proxy for the galaxy of semiconductor measurement needs, we examine it from the perspective of what will be required to continue the semiconductor industry's powerful impact in the world's macro-economy and maintain its exceptional record of numerous technological innovations. This paper concludes with suggestions about ways to strengthen the measurement system for the semiconductor industry.

46 CFR 129.360 - Semiconductor-rectifier systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Semiconductor-rectifier systems. 129.360 Section 129.360... INSTALLATIONS Power Sources and Distribution Systems § 129.360 Semiconductor-rectifier systems. (a) Each semiconductor-rectifier system must have an adequate heat-removal system to prevent overheating. (b) If a...

46 CFR 120.360 - Semiconductor rectifier systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Semiconductor rectifier systems. 120.360 Section 120.360... INSTALLATION Power Sources and Distribution Systems § 120.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents overheating. (b) Where a...

78 FR 40427 - Foreign-Trade Zone (FTZ) 183-Austin, Texas; Notification of Proposed Production Activity; Samsung...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-05

..., Texas; Notification of Proposed Production Activity; Samsung Austin Semiconductor, LLC (Semiconductors); Austin, Texas Samsung Austin Semiconductor, LLC (Samsung), operator of Subzone 183B, submitted a... June 26, 2013. Samsung currently has authority to produce semiconductor memory devices for export...

40 CFR 63.7182 - What parts of my facility does this subpart cover?

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Semiconductor... manufactures semiconductors. (b) An affected source subject to this subpart is the collection of all semiconductor manufacturing process units used to manufacture p-type and n-type semiconductors and active solid...

46 CFR 129.360 - Semiconductor-rectifier systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Semiconductor-rectifier systems. 129.360 Section 129.360... INSTALLATIONS Power Sources and Distribution Systems § 129.360 Semiconductor-rectifier systems. (a) Each semiconductor-rectifier system must have an adequate heat-removal system to prevent overheating. (b) If a...

46 CFR 120.360 - Semiconductor rectifier systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Semiconductor rectifier systems. 120.360 Section 120.360... INSTALLATION Power Sources and Distribution Systems § 120.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents overheating. (b) Where a...

Characterization of the Ecosole HCPV tracker and single module inverter

NASA Astrophysics Data System (ADS)

Carpanelli, Maurizio; Borelli, Gianni; Verdilio, Daniele; De Nardis, Davide; Migali, Fabrizio; Cancro, Carmine; Graditi, Giorgio

2015-09-01

BECAR, the Beghelli group's R&D company, is leading ECOSOLE (Elevated COncentration SOlar Energy), one of the largest European Demonstration projects in solar photovoltaic. ECOSOLE, started in 2012, is focused on the study, design, and realization of new HCPV generator made of high efficiency PV modules equipped with SoG (Silicone on Glass) fresnel lenses and III-V solar cells, and a low cost matched solar tracker with distributed inverters approach. The project also regards the study and demonstration of new high throughput methods for the industrial large scale productions, at very low manufacturing costs. This work reports the description of the characterization of the tracker and single module.

Reconstruction software of the silicon tracker of DAMPE mission

NASA Astrophysics Data System (ADS)

Tykhonov, A.; Gallo, V.; Wu, X.; Zimmer, S.

2017-10-01

DAMPE is a satellite-borne experiment aimed to probe astroparticle physics in the GeV-TeV energy range. The Silicon tracker (STK) is one of the key components of DAMPE, which allows the reconstruction of trajectories (tracks) of detected particles. The non-negligible amount of material in the tracker poses a challenge to its reconstruction and alignment. In this paper we describe methods to address this challenge. We present the track reconstruction algorithm and give insight into the alignment algorithm. We also present our CAD-to-GDML converter, an in-house tool for implementing detector geometry in the software from the CAD drawings of the detector.

P-Type Silicon Strip Sensors for the new CMS Tracker at HL-LHC

NASA Astrophysics Data System (ADS)

Adam, W.; Bergauer, T.; Brondolin, E.; Dragicevic, M.; Friedl, M.; Frühwirth, R.; Hoch, M.; Hrubec, J.; König, A.; Steininger, H.; Waltenberger, W.; Alderweireldt, S.; Beaumont, W.; Janssen, X.; Lauwers, J.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Beghin, D.; Brun, H.; Clerbaux, B.; Delannoy, H.; De Lentdecker, G.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, Th.; Léonard, A.; Luetic, J.; Postiau, N.; Seva, T.; Vanlaer, P.; Vannerom, D.; Wang, Q.; Zhang, F.; Abu Zeid, S.; Blekman, F.; De Bruyn, I.; De Clercq, J.; D'Hondt, J.; Deroover, K.; Lowette, S.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Van Mulders, P.; Van Parijs, I.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Delaere, C.; Delcourt, M.; De Visscher, S.; Francois, B.; Giammanco, A.; Jafari, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Michotte, D.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Szilasi, N.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Härkönen, J.; Lampén, T.; Luukka, P.; Peltola, T.; Tuominen, E.; Tuovinen, E.; Eerola, P.; Tuuva, T.; Baulieu, G.; Boudoul, G.; Caponetto, L.; Combaret, C.; Contardo, D.; Dupasquier, T.; Gallbit, G.; Lumb, N.; Mirabito, L.; Perries, S.; Vander Donckt, M.; Viret, S.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bonnin, C.; Brom, J.-M.; Chabert, E.; Chanon, N.; Charles, L.; Conte, E.; Fontaine, J.-Ch.; Gross, L.; Hosselet, J.; Jansova, M.; Tromson, D.; Autermann, C.; Feld, L.; Karpinski, W.; Kiesel, K. M.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Pierschel, G.; Preuten, M.; Rauch, M.; Schael, S.; Schomakers, C.; Schulz, J.; Schwering, G.; Wlochal, M.; Zhukov, V.; Pistone, C.; Fluegge, G.; Kuensken, A.; Pooth, O.; Stahl, A.; Aldaya, M.; Asawatangtrakuldee, C.; Beernaert, K.; Bertsche, D.; Contreras-Campana, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Gallo, E.; Garay Garcia, J.; Hansen, K.; Haranko, M.; Harb, A.; Hauk, J.; Keaveney, J.; Kalogeropoulos, A.; Kleinwort, C.; Lohmann, W.; Mankel, R.; Maser, H.; Mittag, G.; Muhl, C.; Mussgiller, A.; Pitzl, D.; Reichelt, O.; Savitskyi, M.; Schuetze, P.; Walsh, R.; Zuber, A.; Biskop, H.; Buhmann, P.; Centis-Vignali, M.; Garutti, E.; Haller, J.; Hoffmann, M.; Lapsien, T.; Matysek, M.; Perieanu, A.; Scharf, Ch.; Schleper, P.; Schmidt, A.; Schwandt, J.; Sonneveld, J.; Steinbrück, G.; Vormwald, B.; Wellhausen, J.; Abbas, M.; Amstutz, C.; Barvich, T.; Barth, Ch.; Boegelspacher, F.; De Boer, W.; Butz, E.; Caselle, M.; Colombo, F.; Dierlamm, A.; Freund, B.; Hartmann, F.; Heindl, S.; Husemann, U.; Kornmayer, A.; Kudella, S.; Muller, Th.; Simonis, H. J.; Steck, P.; Weber, M.; Weiler, Th.; Anagnostou, G.; Asenov, P.; Assiouras, P.; Daskalakis, G.; Kyriakis, A.; Loukas, D.; Paspalaki, L.; Siklér, F.; Veszprémi, V.; Bhardwaj, A.; Dalal, R.; Jain, G.; Ranjan, K.; Bakhshiansohl, H.; Behnamian, H.; Khakzad, M.; Naseri, M.; Cariola, P.; Creanza, D.; De Palma, M.; De Robertis, G.; Fiore, L.; Franco, M.; Loddo, F.; Silvestris, L.; Maggi, G.; Martiradonna, S.; My, S.; Selvaggi, G.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Saizu, M. A.; Tricomi, A.; Tuve, C.; Barbagli, G.; Brianzi, M.; Ciaranfi, R.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Latino, G.; Lenzi, P.; Meschini, M.; Paoletti, S.; Russo, L.; Scarlini, E.; Sguazzoni, G.; Strom, D.; Viliani, L.; Ferro, F.; Lo Vetere, M.; Robutti, E.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Pedrini, D.; Azzi, P.; Bacchetta, N.; Bisello, D.; Dall'Osso, M.; Pozzobon, N.; Tosi, M.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Nodari, B.; Riceputi, E.; Re, V.; Traversi, G.; Comotti, D.; Ratti, L.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Cecchi, C.; Checcucci, B.; Ciangottini, D.; Fanò, L.; Gentsos, C.; Ionica, M.; Leonardi, R.; Manoni, E.; Mantovani, G.; Marconi, S.; Mariani, V.; Menichelli, M.; Modak, A.; Morozzi, A.; Moscatelli, F.; Passeri, D.; Placidi, P.; Postolache, V.; Rossi, A.; Saha, A.; Santocchia, A.; Storchi, L.; Spiga, D.; Androsov, K.; Azzurri, P.; Arezzini, S.; Bagliesi, G.; Basti, A.; Boccali, T.; Borrello, L.; Bosi, F.; Castaldi, R.; Ciampa, A.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Magazzu, G.; Martini, L.; Mazzoni, E.; Messineo, A.; Moggi, A.; Morsani, F.; Palla, F.; Palmonari, F.; Raffaelli, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Bellan, R.; Costa, M.; Covarelli, R.; Da Rocha Rolo, M.; Demaria, N.; Rivetti, A.; Dellacasa, G.; Mazza, G.; Migliore, E.; Monteil, E.; Pacher, L.; Ravera, F.; Solano, A.; Fernandez, M.; Gomez, G.; Jaramillo Echeverria, R.; Moya, D.; Gonzalez Sanchez, F. J.; Vila, I.; Virto, A. L.; Abbaneo, D.; Ahmed, I.; Albert, E.; Auzinger, G.; Berruti, G.; Bianchi, G.; Blanchot, G.; Bonnaud, J.; Caratelli, A.; Ceresa, D.; Christiansen, J.; Cichy, K.; Daguin, J.; D'Auria, A.; Detraz, S.; Deyrail, D.; Dondelewski, O.; Faccio, F.; Frank, N.; Gadek, T.; Gill, K.; Honma, A.; Hugo, G.; Jara Casas, L. M.; Kaplon, J.; Kornmayer, A.; Kottelat, L.; Kovacs, M.; Krammer, M.; Lenoir, P.; Mannelli, M.; Marchioro, A.; Marconi, S.; Mersi, S.; Martina, S.; Michelis, S.; Moll, M.; Onnela, A.; Orfanelli, S.; Pavis, S.; Peisert, A.; Pernot, J.-F.; Petagna, P.; Petrucciani, G.; Postema, H.; Rose, P.; Tropea, P.; Troska, J.; Tsirou, A.; Vasey, F.; Vichoudis, P.; Verlaat, B.; Zwalinski, L.; Bachmair, F.; Becker, R.; di Calafiori, D.; Casal, B.; Berger, P.; Djambazov, L.; Donega, M.; Grab, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meinhard, M.; Perozzi, L.; Roeser, U.; Starodumov, A.; Tavolaro, V.; Wallny, R.; Zhu, D.; Amsler, C.; Bösiger, K.; Caminada, L.; Canelli, F.; Chiochia, V.; de Cosa, A.; Galloni, C.; Hreus, T.; Kilminster, B.; Lange, C.; Maier, R.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Taroni, S.; Yang, Y.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Kaestli, H.-C.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Streuli, S.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Jacob, J.; Seif El Nasr-Storey, S.; Cole, J.; Hoad, C.; Hobson, P.; Morton, A.; Reid, I. D.; Auzinger, G.; Bainbridge, R.; Dauncey, P.; Hall, G.; James, T.; Magnan, A.-M.; Pesaresi, M.; Raymond, D. M.; Uchida, K.; Garabedian, A.; Heintz, U.; Narain, M.; Nelson, J.; Sagir, S.; Speer, T.; Swanson, J.; Tersegno, D.; Watson-Daniels, J.; Chertok, M.; Conway, J.; Conway, R.; Flores, C.; Lander, R.; Pellett, D.; Ricci-Tam, F.; Squires, M.; Thomson, J.; Yohay, R.; Burt, K.; Ellison, J.; Hanson, G.; Olmedo, M.; Si, W.; Yates, B. R.; Gerosa, R.; Sharma, V.; Vartak, A.; Yagil, A.; Zevi Della Porta, G.; Dutta, V.; Gouskos, L.; Incandela, J.; Kyre, S.; Mullin, S.; Patterson, A.; Qu, H.; White, D.; Dominguez, A.; Bartek, R.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Apresyan, A.; Bolla, G.; Burkett, K.; Butler, J. N.; Canepa, A.; Cheung, H. W. K.; Chramowicz, J.; Christian, D.; Cooper, W. E.; Deptuch, G.; Derylo, G.; Gingu, C.; Grünendahl, S.; Hasegawa, S.; Hoff, J.; Howell, J.; Hrycyk, M.; Jindariani, S.; Johnson, M.; Kahlid, F.; Lei, C. M.; Lipton, R.; Lopes De Sá, R.; Liu, T.; Los, S.; Matulik, M.; Merkel, P.; Nahn, S.; Prosser, A.; Rivera, R.; Schneider, B.; Sellberg, G.; Shenai, A.; Spiegel, L.; Tran, N.; Uplegger, L.; Voirin, E.; Berry, D. R.; Chen, X.; Ennesser, L.; Evdokimov, A.; Evdokimov, O.; Gerber, C. E.; Hofman, D. J.; Makauda, S.; Mills, C.; Sandoval Gonzalez, I. D.; Alimena, J.; Antonelli, L. J.; Francis, B.; Hart, A.; Hill, C. S.; Parashar, N.; Stupak, J.; Bortoletto, D.; Bubna, M.; Hinton, N.; Jones, M.; Miller, D. H.; Shi, X.; Tan, P.; Baringer, P.; Bean, A.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Wilson, G.; Ivanov, A.; Mendis, R.; Mitchell, T.; Skhirtladze, N.; Taylor, R.; Anderson, I.; Fehling, D.; Gritsan, A.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Monroy, J.; Siado, J.; Hahn, K.; Sevova, S.; Sung, K.; Trovato, M.; Bartz, E.; Gershtein, Y.; Halkiadakis, E.; Kyriacou, S.; Lath, A.; Nash, K.; Osherson, M.; Schnetzer, S.; Stone, R.; Walker, M.; Malik, S.; Norberg, S.; Ramirez Vargas, J. E.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kharchilava, A.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; McDermott, K.; Mirman, N.; Rinkevicius, A.; Ryd, A.; Salvati, E.; Skinnari, L.; Soffi, L.; Tao, Z.; Thom, J.; Tucker, J.; Zientek, M.; Akgün, B.; Ecklund, K. M.; Kilpatrick, M.; Nussbaum, T.; Zabel, J.; Betchart, B.; Covarelli, R.; Demina, R.; Hindrichs, O.; Petrillo, G.; Eusebi, R.; Osipenkov, I.; Perloff, A.; Ulmer, K. A.

2017-06-01

The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. This paper describes the main measurement results and conclusions that motivated this decision.

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, David K.; Tracy, C. Edwin

1987-01-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use thermoelectric generators.

Thermoelectric generator and method for the fabrication thereof

DOEpatents

Benson, D.K.; Tracy, C.E.

1984-08-01

A thermoelectric generator using semiconductor elements for responding to a temperature gradient to produce electrical energy with all of the semiconductor elements being of the same type is disclosed. A continuous process for forming substrates on which the semiconductor elements and superstrates are deposited and a process for forming the semiconductor elements on the substrates are also disclosed. The substrates with the semiconductor elements thereon are combined with superstrates to form modules for use as thermoelectric generators.

Contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication

DOEpatents

Sopori, Bhushan

2014-05-27

Methods for contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication are provided. In one embodiment, a method for fabricating an electrical semiconductor device comprises: a first step that includes gettering of impurities from a semiconductor wafer and forming a backsurface field; and a second step that includes forming a front contact for the semiconductor wafer, wherein the second step is performed after completion of the first step.

Using "Tracker" to Prove the Simple Harmonic Motion Equation

ERIC Educational Resources Information Center

Kinchin, John

2016-01-01

Simple harmonic motion (SHM) is a common topic for many students to study. Using the free, though versatile, motion tracking software; "Tracker", we can extend the students experience and show that the general equation for SHM does lead to the correct period of a simple pendulum.

Radar Detection of Marine Mammals

DTIC Science & Technology

2010-09-30

associative tracker using the Munkres algorithm was used. This was then expanded to include a track - before - detect algorithm, the Baysean Field...small, slow moving objects (i.e. whales). In order to address the third concern (M2 mode), we have tested using a track - before - detect tracker termed

Summer 1980 Directory of Navy Electro-Optical Professionals.

DTIC Science & Technology

1981-01-19

4864 E-0 Oceanographic Applications Pressman , A. 335 4864 Satellite Analysis-, Environinental/Intelligence Tooma. S, 332 4810 E-0 Measurement of Sea...Teate. George 3924 372 1/ TV Trackers 3722 Teppo, E. A. 3151 3723 Laser Technology Thomas, Virgil 31404 5283 TV Camera/Trackers Thompson, Barry 3943

75 FR 45093 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

...; student tracker database updates, 16 hours. Burden Hours: 11,328. Needs and Uses: Under the authority of... application, by academic professors/advisors. NOAA OEd student scholar alumni are also requested to provide... tracker database with the required student information. In addition, the collected student data supports...

MediaTracker system

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

Sandoval, D. M.; Strittmatter, R. B.; Abeyta, J. D.

2004-01-01

The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access tomore » the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can accommodate several methods of positive identification including smart cards and biometrics. Currently, we have three mechanisms that provide added security for accountability and tracking purposes. One mechanism consists of a portable, hand-held inventory scanner, which allows the custodian to physically track the items that are not accessible within a particular area. The second mechanism is a radio frequency identification (RFID) consisting of a monitoring portal, which tracks and logs in a database all activity tagged of items that pass through the portals. The third mechanism consists of an electronic tagging of a flash memory device for automated inventory of CREM in storage. By modifying this USB device the user is provided with added assurance, limiting the data from being obtained from any other computer.« less

78 FR 68814 - Subzone 183B; Authorization of Production Activity; Samsung Austin Semiconductor, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-15

... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-70-2013] Subzone 183B; Authorization of Production Activity; Samsung Austin Semiconductor, LLC (Semiconductors); Austin, Texas On June 26, 2013, Samsung Austin Semiconductor, LLC submitted a notification of proposed export production activity to the...

40 CFR 63.7195 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... units used to manufacture p-type and n-type semiconductors or active solid state devices from a wafer.... Examples of semiconductor or related solid state devices include semiconductor diodes, semiconductor stacks... permanently attached to motor vehicles such as trucks, railcars, barges, or ships; (2) Flow-through tanks...

40 CFR 63.7195 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... units used to manufacture p-type and n-type semiconductors or active solid state devices from a wafer.... Examples of semiconductor or related solid state devices include semiconductor diodes, semiconductor stacks... permanently attached to motor vehicles such as trucks, railcars, barges, or ships; (2) Flow-through tanks...

40 CFR 63.7195 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... units used to manufacture p-type and n-type semiconductors or active solid state devices from a wafer.... Examples of semiconductor or related solid state devices include semiconductor diodes, semiconductor stacks... permanently attached to motor vehicles such as trucks, railcars, barges, or ships; (2) Flow-through tanks...

Uncertainty estimation and multi sensor fusion for kinematic laser tracker measurements

NASA Astrophysics Data System (ADS)

Ulrich, Thomas

2013-08-01

Laser trackers are widely used to measure kinematic tasks such as tracking robot movements. Common methods to evaluate the uncertainty in the kinematic measurement include approximations specified by the manufacturers, various analytical adjustment methods and the Kalman filter. In this paper a new, real-time technique is proposed, which estimates the 4D-path (3D-position + time) uncertainty of an arbitrary path in space. Here a hybrid system estimator is applied in conjunction with the kinematic measurement model. This method can be applied to processes, which include various types of kinematic behaviour, constant velocity, variable acceleration or variable turn rates. The new approach is compared with the Kalman filter and a manufacturer's approximations. The comparison was made using data obtained by tracking an industrial robot's tool centre point with a Leica laser tracker AT901 and a Leica laser tracker LTD500. It shows that the new approach is more appropriate to analysing kinematic processes than the Kalman filter, as it reduces overshoots and decreases the estimated variance. In comparison with the manufacturer's approximations, the new approach takes account of kinematic behaviour with an improved description of the real measurement process and a reduction in estimated variance. This approach is therefore well suited to the analysis of kinematic processes with unknown changes in kinematic behaviour as well as the fusion among laser trackers.

ATP-containing vesicles in stria vascular marginal cell cytoplasms in neonatal rat cochlea are lysosomes.

PubMed

Liu, Jun; Liu, Wenjing; Yang, Jun

2016-02-11

We confirmed that ATP is released from cochlear marginal cells in the stria vascular but the cell organelle in which ATP stores was not identified until now. Thus, we studied the ATP-containing cell organelles and suggest that these are lysosomes. Primary cultures of marginal cells of Sprague-Dawley rats aged 1-3 days was established. Vesicles within marginal cells stained with markers were identified under confocal laser scanning microscope and transmission electron microscope (TEM). Then ATP release from marginal cells was measured after glycyl-L-phenylalanine-ß- naphthylamide (GPN) treatment using a bioluminescent assay. Quinacrine-stained granules within marginal cells were labeled with LysoTracker, a lysosome tracer, and lysosomal-associated membrane protein 1(LAMP1), but not labeled with the mitochondrial tracer MitoTracker. Furthermore, LysoTracker-labelled puncta showed accumulation of Mant-ATP, an ATP analog. Treatment with 200 μM GPN quenched fluorescently labeled puncta after incubation with LysoTracker or quinacrine, but not MitoTracker. Quinacrine-labeled organelles observed by TEM were lysosomes, and an average 27.7 percent increase in ATP luminescence was observed in marginal cells extracellular fluid after GPN treatment. ATP-containing vesicles in cochlear marginal cells of the stria vascular from neonatal rats are likely lysosomes. ATP release from marginal cells may be via Ca(2+)-dependent lysosomal exocytosis.

Acute Care for Elders (ACE) Tracker and e-Geriatrician: Methods to Disseminate ACE Concepts to Hospitals with No Geriatricians on Staff

PubMed Central

Malone, Michael L.; Vollbrecht, Marsha; Stephenson, Jeff; Burke, Laura; Pagel, Patti; Goodwin, James S.

2014-01-01

This article describes an innovative method to disseminate the Acute Care for Elders (ACE) model of care for hospitalized older patients implemented at 11 community hospitals in Wisconsin. The ACE Tracker is a computer-generated checklist of all older patients in a facility that takes information from multiple areas of the electronic medical record to identify the older patients’ risk factors for functional decline and poor outcomes. The ACE Tracker report was validated against in-person observation of the older patients and found to be accurate. Interdisciplinary teams on medical–surgical units use this summary report to review each patient’s plan of care and to efficiently assess the patients who are vulnerable to poor hospital outcomes. The ACE Tracker is also used during regular consultation provided through teleconferencing between an off-site geriatrician (e-Geriatrician) and the local ACE team. The effect of the ACE Tracker and e-Geriatrician models was assessed by measuring use of urinary catheters, physical restraints, high-risk medications, and social service evaluation at a single hospital for the 6 months before and after implementation of the models. There were significant improvements in urinary catheter and physical therapy referrals but no significant changes in the other outcomes. There was no change in the length of stay or in the rate of hospital readmission within 30 days. PMID:20122048

Contradictions in digital health engagement: An activity tracker’s ambiguous influence on vulnerable young adults’ engagement in own health

PubMed Central

Bertelsen, Pernille

2018-01-01

Objective Activity trackers are designed to support individuals in monitoring and increasing their physical activity. The use of activity trackers among individuals diagnosed with depression and anxiety has not yet been examined. This pilot study investigates how this target group engages with an activity tracker during a 10-week health intervention aimed to increase their physical activity level and improve their physical and mental health. Methods Two groups of 11 young adults (aged 18–29 years) diagnosed with depression or anxiety participated in the digital health intervention. The study used mixed methods to investigate the research question. Quantitative health data were used to assess the intervention’s influence on the participants’ health and qualitative data provided insights into the participants’ digital health experience. Results The study demonstrated an ambiguous influence from the use of an activity tracker with positive physical and mental health results, but a fading and even negative digital health engagement and counterproductive competition. Conclusions The ambiguous results identify a need for (1) developing strategies for health professionals to provide supervised use of activity trackers and support the target groups’ abilities to convert health information about physical activity into positive health strategies, and (2) designing alternatives for health promoting IT targeted users who face challenges and need motivation beyond self-tracking and competition.

Effective star tracking method based on optical flow analysis for star trackers.

PubMed

Sun, Ting; Xing, Fei; Wang, Xiaochu; Li, Jin; Wei, Minsong; You, Zheng

2016-12-20

Benefiting from rapid development of imaging sensor technology, modern optical technology, and a high-speed computing chip, the star tracker's accuracy, dynamic performance, and update rate have been greatly improved with low power consumption and miniature size. The star tracker is currently one of the most competitive attitude measurement sensors. However, due to restrictions of the optical imaging system, difficulties still exist in moving star spot detection and star tracking when in special motion conditions. An effective star tracking method based on optical flow analysis for star trackers is proposed in this paper. Spot-based optical flow, based on a gray gradient between two adjacent star images, is analyzed to distinguish the star spot region and obtain an accurate star spot position so that the star tracking can keep continuous under high dynamic conditions. The obtained star vectors and extended Kalman filter (EKF) are then combined to conduct an angular velocity estimation to ensure region prediction of the star spot; this can be combined with the optical flow analysis result. Experiment results show that the method proposed in this paper has advantages in conditions of large angular velocity and large angular acceleration, despite the presence of noise. Higher functional density and better performance can be achieved; thus, the star tracker can be more widely applied in small satellites, remote sensing, and other complex space missions.

ATP-containing vesicles in stria vascular marginal cell cytoplasms in neonatal rat cochlea are lysosomes

PubMed Central

Liu, Jun; Liu, Wenjing; Yang, Jun

2016-01-01

We confirmed that ATP is released from cochlear marginal cells in the stria vascular but the cell organelle in which ATP stores was not identified until now. Thus, we studied the ATP-containing cell organelles and suggest that these are lysosomes. Primary cultures of marginal cells of Sprague-Dawley rats aged 1–3 days was established. Vesicles within marginal cells stained with markers were identified under confocal laser scanning microscope and transmission electron microscope (TEM). Then ATP release from marginal cells was measured after glycyl-L-phenylalanine-ß- naphthylamide (GPN) treatment using a bioluminescent assay. Quinacrine-stained granules within marginal cells were labeled with LysoTracker, a lysosome tracer, and lysosomal-associated membrane protein 1(LAMP1), but not labeled with the mitochondrial tracer MitoTracker. Furthermore, LysoTracker-labelled puncta showed accumulation of Mant-ATP, an ATP analog. Treatment with 200 μM GPN quenched fluorescently labeled puncta after incubation with LysoTracker or quinacrine, but not MitoTracker. Quinacrine-labeled organelles observed by TEM were lysosomes, and an average 27.7 percent increase in ATP luminescence was observed in marginal cells extracellular fluid after GPN treatment. ATP-containing vesicles in cochlear marginal cells of the stria vascular from neonatal rats are likely lysosomes. ATP release from marginal cells may be via Ca2+-dependent lysosomal exocytosis. PMID:26864824

Bar coded retroreflective target

DOEpatents

Vann, Charles S.

2000-01-01

This small, inexpensive, non-contact laser sensor can detect the location of a retroreflective target in a relatively large volume and up to six degrees of position. The tracker's laser beam is formed into a plane of light which is swept across the space of interest. When the beam illuminates the retroreflector, some of the light returns to the tracker. The intensity, angle, and time of the return beam is measured to calculate the three dimensional location of the target. With three retroreflectors on the target, the locations of three points on the target are measured, enabling the calculation of all six degrees of target position. Until now, devices for three-dimensional tracking of objects in a large volume have been heavy, large, and very expensive. Because of the simplicity and unique characteristics of this tracker, it is capable of three-dimensional tracking of one to several objects in a large volume, yet it is compact, light-weight, and relatively inexpensive. Alternatively, a tracker produces a diverging laser beam which is directed towards a fixed position, and senses when a retroreflective target enters the fixed field of view. An optically bar coded target can be read by the tracker to provide information about the target. The target can be formed of a ball lens with a bar code on one end. As the target moves through the field, the ball lens causes the laser beam to scan across the bar code.

Electrodes for Semiconductor Gas Sensors

PubMed Central

Lee, Sung Pil

2017-01-01

The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode–semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode–semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect. PMID:28346349

Epitaxial Growth of Cubic Crystalline Semiconductor Alloys on Basal Plane of Trigonal or Hexagonal Crystal

NASA Technical Reports Server (NTRS)

Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor)

2011-01-01

Hetero-epitaxial semiconductor materials comprising cubic crystalline semiconductor alloys grown on the basal plane of trigonal and hexagonal substrates, in which misfit dislocations are reduced by approximate lattice matching of the cubic crystal structure to underlying trigonal or hexagonal substrate structure, enabling the development of alloyed semiconductor layers of greater thickness, resulting in a new class of semiconductor materials and corresponding devices, including improved hetero-bipolar and high-electron mobility transistors, and high-mobility thermoelectric devices.

Physical Activity Assessment Using an Activity Tracker in Patients with Rheumatoid Arthritis and Axial Spondyloarthritis: Prospective Observational Study

PubMed Central

Servy, Hervé; Molto, Anna; Sellam, Jérémie; Foltz, Violaine; Gandjbakhch, Frédérique; Hudry, Christophe; Mitrovic, Stéphane; Fautrel, Bruno; Gossec, Laure

2018-01-01

Background Physical activity can be tracked using mobile devices and is recommended in rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) management. The World Health Organization (WHO) recommends at least 150 min per week of moderate to vigorous physical activity (MVPA). Objective The objectives of this study were to assess and compare physical activity and its patterns in patients with RA and axSpA using an activity tracker and to assess the feasibility of mobile devices in this population. Methods This multicentric prospective observational study (ActConnect) included patients who had definite RA or axSpA, and a smartphone. Physical activity was assessed over 3 months using a mobile activity tracker, recording the number of steps per minute. The number of patients reaching the WHO recommendations was calculated. RA and axSpA were compared, using linear mixed models, for number of steps, proportion of morning steps, duration of total activity, and MVPA. Physical activity trajectories were identified using the K-means method, and factors related to the low activity trajectory were explored by logistic regression. Acceptability was assessed by the mean number of days the tracker was worn over the 3 months (ie, adherence), the percentage of wearing time, and by an acceptability questionnaire. Results A total of 157 patients (83 RA and 74 axSpA) were analyzed; 36.3% (57/157) patients were males, and their mean age was 46 (standard deviation [SD] 12) years and mean disease duration was 11 (SD 9) years. RA and axSpA patients had similar physical activity levels of 16 (SD 11) and 15 (SD 12) min per day of MVPA (P=.80), respectively. Only 27.4% (43/157) patients reached the recommendations with a mean MVPA of 106 (SD 77) min per week. The following three trajectories were identified with constant activity: low (54.1% [85/157] of patients), moderate (42.7% [67/157] of patients), and high (3.2% [5/157] of patients) levels of MVPA. A higher body mass index was significantly related to less physical activity (odds ratio 1.12, 95% CI 1.11-1.14). The activity trackers were worn during a mean of 79 (SD 17) days over the 90 days follow-up. Overall, patients considered the use of the tracker very acceptable, with a mean score of 8 out 10. Conclusions Patients with RA and axSpA performed insufficient physical activity with similar levels in both groups, despite the differences between the 2 diseases. Activity trackers allow longitudinal assessment of physical activity in these patients. The good adherence to this study and the good acceptability of wearing activity trackers confirmed the feasibility of the use of a mobile activity tracker in patients with rheumatic diseases. PMID:29295810

Tracker: Image-Processing and Object-Tracking System Developed

NASA Technical Reports Server (NTRS)

Klimek, Robert B.; Wright, Theodore W.

1999-01-01

Tracker is an object-tracking and image-processing program designed and developed at the NASA Lewis Research Center to help with the analysis of images generated by microgravity combustion and fluid physics experiments. Experiments are often recorded on film or videotape for analysis later. Tracker automates the process of examining each frame of the recorded experiment, performing image-processing operations to bring out the desired detail, and recording the positions of the objects of interest. It can load sequences of images from disk files or acquire images (via a frame grabber) from film transports, videotape, laser disks, or a live camera. Tracker controls the image source to automatically advance to the next frame. It can employ a large array of image-processing operations to enhance the detail of the acquired images and can analyze an arbitrarily large number of objects simultaneously. Several different tracking algorithms are available, including conventional threshold and correlation-based techniques, and more esoteric procedures such as "snake" tracking and automated recognition of character data in the image. The Tracker software was written to be operated by researchers, thus every attempt was made to make the software as user friendly and self-explanatory as possible. Tracker is used by most of the microgravity combustion and fluid physics experiments performed by Lewis, and by visiting researchers. This includes experiments performed on the space shuttles, Mir, sounding rockets, zero-g research airplanes, drop towers, and ground-based laboratories. This software automates the analysis of the flame or liquid s physical parameters such as position, velocity, acceleration, size, shape, intensity characteristics, color, and centroid, as well as a number of other measurements. It can perform these operations on multiple objects simultaneously. Another key feature of Tracker is that it performs optical character recognition (OCR). This feature is useful in extracting numerical instrumentation data that are embedded in images. All the results are saved in files for further data reduction and graphing. There are currently three Tracking Systems (workstations) operating near the laboratories and offices of Lewis Microgravity Science Division researchers. These systems are used independently by students, scientists, and university-based principal investigators. The researchers bring their tapes or films to the workstation and perform the tracking analysis. The resultant data files generated by the tracking process can then be analyzed on the spot, although most of the time researchers prefer to transfer them via the network to their offices for further analysis or plotting. In addition, many researchers have installed Tracker on computers in their office for desktop analysis of digital image sequences, which can be digitized by the Tracking System or some other means. Tracker has not only provided a capability to efficiently and automatically analyze large volumes of data, saving many hours of tedious work, but has also provided new capabilities to extract valuable information and phenomena that was heretofore undetected and unexploited.

Method for manufacturing electrical contacts for a thin-film semiconductor device

DOEpatents

Carlson, David E.; Dickson, Charles R.; D'Aiello, Robert V.

1988-11-08

A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Electrical contacts for a thin-film semiconductor device

DOEpatents

Carlson, David E.; Dickson, Charles R.; D'Aiello, Robert V.

1989-08-08

A method of fabricating spaced-apart back contacts on a thin film of semiconductor material by forming strips of buffer material on top of the semiconductor material in locations corresponding to the desired dividing lines between back contacts, forming a film of metal substantially covering the semiconductor material and buffer strips, and scribing portions of the metal film overlying the buffer strips with a laser without contacting the underlying semiconductor material to separate the metal layer into a plurality of back contacts. The buffer material serves to protect the underlying semiconductor material from being damaged during the laser scribing. Back contacts and multi-cell photovoltaic modules incorporating such back contacts also are disclosed.

Lattice matched semiconductor growth on crystalline metallic substrates

DOEpatents

Norman, Andrew G; Ptak, Aaron J; McMahon, William E

2013-11-05

Methods of fabricating a semiconductor layer or device and said devices are disclosed. The methods include but are not limited to providing a metal or metal alloy substrate having a crystalline surface with a known lattice parameter (a). The methods further include growing a crystalline semiconductor alloy layer on the crystalline substrate surface by coincident site lattice matched epitaxy. The semiconductor layer may be grown without any buffer layer between the alloy and the crystalline surface of the substrate. The semiconductor alloy may be prepared to have a lattice parameter (a') that is related to the lattice parameter (a). The semiconductor alloy may further be prepared to have a selected band gap.

Will Future Measurement Needs of the Semiconductor Industry Be Met?

PubMed Central

Bennett, Herbert S.

2007-01-01

We discuss the ability of the nation’s measurement system to meet future metrology needs of the semiconductor industry. Lacking an acceptable metric for assessing the health of metrology for the semiconductor industry, we identify a limited set of unmet measurement needs. Assuming that this set of needs may serve as proxy for the galaxy of semiconductor measurement needs, we examine it from the perspective of what will be required to continue the semiconductor industry’s powerful impact in the world’s macro-economy and maintain its exceptional record of numerous technological innovations. This paper concludes with suggestions about ways to strengthen the measurement system for the semiconductor industry. PMID:27110452

Teaching Astronomy Using Tracker

ERIC Educational Resources Information Center

Belloni, Mario; Christian, Wolfgang; Brown, Douglas

2013-01-01

A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

75 FR 20981 - Proposed Information Collection; Comment Request; Educational Partnership Program (EPP) and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

... completion of a NOAA student scholar reference form in support of the scholarship application by academic... internal tracking purposes. NOAA OEd grantees are required to update the student tracker database with the... tracker database form, 16 hours; graduate application form, 8 hours; undergraduate application form, 8...

76 FR 36883 - Defense Federal Acquisition Regulation Supplement; Synchronized Predeployment and Operational...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-23

... Tracker (SPOT) (DFARS Case 2011-D030) AGENCY: Defense Acquisition Regulations System, Department of... requirements associated with the Synchronized Predeployment and Operational Tracker (SPOT) system. DATES... (SPOT)-generated letter of authorization.'' The change in title is being made at DFARS 225.7402-3(e) and...

A Bio-Energetic Model for North Atlantic Right Whales: Locomotion, Anatomy and Diving Behavior

DTIC Science & Technology

2008-01-01

tracker was visualized with Avizo , formerly Amira, software (Mercury Computing, Inc.) (Figure 3). The particle tracker feature greatly increased our...plots in Figures 3 and 4, respectively. Figure 3. Example of a network script from Avizo that controls the manipulation and visualization

Band-Gap Engineering at a Semiconductor-Crystalline Oxide Interface

DOE PAGES

Jahangir-Moghadam, Mohammadreza; Ahmadi-Majlan, Kamyar; Shen, Xuan; ...

2015-02-09

The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZr xTi 1-xO₃ and Ge, in which the band gap of the former is enhanced with Zr content x.more » We present structural and electrical characterization of SrZr xTi 1-xO₃-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.« less

Light emitting diode with porous SiC substrate and method for fabricating

DOEpatents

Li, Ting; Ibbetson, James; Keller, Bernd

2005-12-06

A method and apparatus for forming a porous layer on the surface of a semiconductor material wherein an electrolyte is provided and is placed in contact with one or more surfaces of a layer of semiconductor material. The electrolyte is heated and a bias is introduced across said electrolyte and the semiconductor material causing a current to flow between the electrolyte and the semiconductor material. The current forms a porous layer on the one or more surfaces of the semiconductor material in contact with the electrolyte. The semiconductor material with its porous layer can serve as a substrate for a light emitter. A semiconductor emission region can be formed on the substrate. The emission region is capable of emitting light omnidirectionally in response to a bias, with the porous layer enhancing extraction of the emitting region light passing through the substrate.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe.

PubMed

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe

NASA Astrophysics Data System (ADS)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Organic photosensitive cells grown on rough electrode with nano-scale morphology control

DOEpatents

Yang, Fan [Piscataway, NJ; Forrest, Stephen R [Ann Arbor, MI

2011-06-07

An optoelectronic device and a method for fabricating the optoelectronic device includes a first electrode disposed on a substrate, an exposed surface of the first electrode having a root mean square roughness of at least 30 nm and a height variation of at least 200 nm, the first electrode being transparent. A conformal layer of a first organic semiconductor material is deposited onto the first electrode by organic vapor phase deposition, the first organic semiconductor material being a small molecule material. A layer of a second organic semiconductor material is deposited over the conformal layer. At least some of the layer of the second organic semiconductor material directly contacts the conformal layer. A second electrode is deposited over the layer of the second organic semiconductor material. The first organic semiconductor material is of a donor-type or an acceptor-type relative to the second organic semiconductor material, which is of the other material type.

Photovoltaic healing of non-uniformities in semiconductor devices

DOEpatents

Karpov, Victor G.; Roussillon, Yann; Shvydka, Diana; Compaan, Alvin D.; Giolando, Dean M.

2006-08-29

A method of making a photovoltaic device using light energy and a solution to normalize electric potential variations in the device. A semiconductor layer having nonuniformities comprising areas of aberrant electric potential deviating from the electric potential of the top surface of the semiconductor is deposited onto a substrate layer. A solution containing an electrolyte, at least one bonding material, and positive and negative ions is applied over the top surface of the semiconductor. Light energy is applied to generate photovoltage in the semiconductor, causing a redistribution of the ions and the bonding material to the areas of aberrant electric potential. The bonding material selectively bonds to the nonuniformities in a manner such that the electric potential of the nonuniformities is normalized relative to the electric potential of the top surface of the semiconductor layer. A conductive electrode layer is then deposited over the top surface of the semiconductor layer.

Semiconductor films on flexible iridium substrates

DOEpatents

Goyal, Amit

2005-03-29

A laminate semiconductor article includes a flexible substrate, an optional biaxially textured oxide buffer system on the flexible substrate, a biaxially textured Ir-based buffer layer on the substrate or the buffer system, and an epitaxial layer of a semiconductor. Ir can serve as a substrate with an epitaxial layer of a semiconductor thereon.

Semiconductor apparatus utilizing gradient freeze and liquid-solid techniques

NASA Technical Reports Server (NTRS)

Fleurial, Jean-Pierre (Inventor); Caillat, Thierry F. (Inventor); Borshchevsky, Alexander (Inventor)

1998-01-01

Transition metals of Group VIII (Co, Rh and Ir) have been prepared as semiconductor compounds with the general formula TSb.sub.3. The skutterudite-type crystal lattice structure of these semiconductor compounds and their enhanced thermoelectric properties results in semiconductor materials which may be used in the fabrication of thermoelectric elements to substantially improve the efficiency of the resulting thermoelectric device. Semiconductor materials having the desired skutterudite-type crystal lattice structure may be prepared in accordance with the present invention by using vertical gradient freezing techniques and/or liquid phase sintering techniques. Measurements of electrical and thermal transport properties of selected semiconductor materials prepared in accordance with the present invention, demonstrated high Hall mobilities (up to 1200 cm.sup.2.V.sup.-1.s.sup.-1) and good Seebeck coefficients (up to 150 .mu.VK.sup.-1 between 300.degree. C. and 700.degree. C.). Optimizing the transport properties of semiconductor materials prepared from elemental mixtures Co, Rh, Ir and Sb resulted in a substantial increase in the thermoelectric figure of merit (ZT) at temperatures as high as 400.degree. C. for thermoelectric elements fabricated from such semiconductor materials.

Toward designing semiconductor-semiconductor heterojunctions for photocatalytic applications

NASA Astrophysics Data System (ADS)

Zhang, Liping; Jaroniec, Mietek

2018-02-01

Semiconductor photocatalysts show a great potential for environmental and energy-related applications, however one of the major disadvantages is their relatively low photocatalytic performance due to the recombination of electron-hole pairs. Therefore, intensive research is being conducted toward design of heterojunctions, which have been shown to be effective for improving the charge-transfer properties and efficiency of photocatalysts. According to the type of band alignment and direction of internal electric field, heterojunctions are categorized into five different types, each of which is associated with its own charge transfer characteristics. Since the design of heterojunctions requires the knowledge of band edge positions of component semiconductors, the commonly used techniques for the assessment of band edge positions are reviewed. Among them the electronegativity-based calculation method is applied for a large number of popular visible-light-active semiconductors, including some widely investigated bismuth-containing semiconductors. On basis of the calculated band edge positions and the type of component semiconductors reported, heterojunctions composed of the selected bismuth-containing semiconductors are proposed. Finally, the most popular synthetic techniques for the fabrication of heterojunctions are briefly discussed.

Semiconductor sensors

NASA Technical Reports Server (NTRS)

Gatos, Harry C. (Inventor); Lagowski, Jacek (Inventor)

1977-01-01

A semiconductor sensor adapted to detect with a high degree of sensitivity small magnitudes of a mechanical force, presence of traces of a gas or light. The sensor includes a high energy gap (i.e., .about. 1.0 electron volts) semiconductor wafer. Mechanical force is measured by employing a non-centrosymmetric material for the semiconductor. Distortion of the semiconductor by the force creates a contact potential difference (cpd) at the semiconductor surface, and this cpd is determined to give a measure of the force. When such a semiconductor is subjected to illumination with an energy less than the energy gap of the semiconductors, such illumination also creates a cpd at the surface. Detection of this cpd is employed to sense the illumination itself or, in a variation of the system, to detect a gas. When either a gas or light is to be detected and a crystal of a non-centrosymmetric material is employed, the presence of gas or light, in appropriate circumstances, results in a strain within the crystal which distorts the same and the distortion provides a mechanism for qualitative and quantitative evaluation of the gas or the light, as the case may be.

Ambipolar Small-Molecule:Polymer Blend Semiconductors for Solution-Processable Organic Field-Effect Transistors.

PubMed

Kang, Minji; Hwang, Hansu; Park, Won-Tae; Khim, Dongyoon; Yeo, Jun-Seok; Kim, Yunseul; Kim, Yeon-Ju; Noh, Yong-Young; Kim, Dong-Yu

2017-01-25

We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

Solid state radiative heat pump

DOEpatents

Berdahl, Paul H.

1986-01-01

A solid state radiative heat pump (10, 50, 70) operable at room temperature (300.degree. K.) utilizes a semiconductor having a gap energy in the range of 0.03-0.25 eV and operated reversibly to produce an excess or deficit of charge carriers as compared to thermal equilibrium. In one form of the invention (10, 70) an infrared semiconductor photodiode (21, 71) is used, with forward or reverse bias, to emit an excess or deficit of infrared radiation. In another form of the invention (50), a homogeneous semiconductor (51) is subjected to orthogonal magnetic and electric fields to emit an excess or deficit of infrared radiation. Three methods of enhancing transmission of radiation through the active surface of the semiconductor are disclosed. In one method, an anti-reflection layer (19) is coated into the active surface (13) of the semiconductor (11), the anti-reflection layer (19) having an index of refraction equal to the square root of that of the semiconductor (11). In the second method, a passive layer (75) is spaced from the active surface (73) of the semiconductor (71) by a submicron vacuum gap, the passive layer having an index of refractive equal to that of the semiconductor. In the third method, a coupler (91) with a paraboloid reflecting surface (92) is in contact with the active surface (13, 53) of the semiconductor (11, 51), the coupler having an index of refraction about the same as that of the semiconductor.

FOREWORD: Focus on Superconductivity in Semiconductors Focus on Superconductivity in Semiconductors

NASA Astrophysics Data System (ADS)

Takano, Yoshihiko

2008-12-01

Since the discovery of superconductivity in diamond, much attention has been given to the issue of superconductivity in semiconductors. Because diamond has a large band gap of 5.5 eV, it is called a wide-gap semiconductor. Upon heavy boron doping over 3×1020 cm-3, diamond becomes metallic and demonstrates superconductivity at temperatures below 11.4 K. This discovery implies that a semiconductor can become a superconductor upon carrier doping. Recently, superconductivity was also discovered in boron-doped silicon and SiC semiconductors. The number of superconducting semiconductors has increased. In 2008 an Fe-based superconductor was discovered in a research project on carrier doping in a LaCuSeO wide-gap semiconductor. This discovery enhanced research activities in the field of superconductivity, where many scientists place particular importance on superconductivity in semiconductors. This focus issue features a variety of topics on superconductivity in semiconductors selected from the 2nd International Workshop on Superconductivity in Diamond and Related Materials (IWSDRM2008), which was held at the National Institute for Materials Science (NIMS), Tsukuba, Japan in July 2008. The 1st workshop was held in 2005 and was published as a special issue in Science and Technology of Advanced Materials (STAM) in 2006 (Takano 2006 Sci. Technol. Adv. Mater. 7 S1). The selection of papers describe many important experimental and theoretical studies on superconductivity in semiconductors. Topics on boron-doped diamond include isotope effects (Ekimov et al) and the detailed structure of boron sites, and the relation between superconductivity and disorder induced by boron doping. Regarding other semiconductors, the superconducting properties of silicon and SiC (Kriener et al, Muranaka et al and Yanase et al) are discussed, and In2O3 (Makise et al) is presented as a new superconducting semiconductor. Iron-based superconductors are presented as a new series of high-TC superconductors (Tamegai et al), and the mechanism of superconductivity is discussed. Last but not least, a novel highest-density phase of boron is produced and characterized (Zarechnaya et al). We hope that this focus issue will help readers to understand the frontiers of superconductivity in semiconductors and assist in the application of new devices using a combination of superconductivity and semiconductivity.

Onorbit IMU alignment error budget

NASA Technical Reports Server (NTRS)

Corson, R. W.

1980-01-01

The Star Tracker, Crew Optical Alignment Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU alignment accuracy for STS-1. The expected standard deviation in the IMU alignment error for STS-1 type alignments was determined to be 72 arc seconds per axis for star tracker alignments and 188 arc seconds per axis for COAS alignments. These estimates are based on current knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.

P-Type Silicon Strip Sensors for the new CMS Tracker at HL-LHC

DOE PAGES

Adam, W.; Bergauer, T.; Brondolin, E.; ...

2017-06-27

The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. Furthermore, this paper describes the main measurement results and conclusions thatmore » motivated this decision.« less

CMS tracker towards the HL-LHC

NASA Astrophysics Data System (ADS)

Alunni Solestizi, L.

2015-01-01

In sight of the incoming new LHC era (High Luminosity - LHC), characterized by a jump forward in the precision boundary and in the event rate, all the CMS sub-detector are developing and studying innovative strategies of trigger, pattern recognition, event timing and so on. A crucial aspect will be the online event selection: a totally new paradigm is needed, given the huge amount of events. In this picture the most granular and innermost sub-detector, the tracker, will play a decisive role. The phase-2 tracker will be involved in the L1 Trigger and, taking advantage of both the Associative Memories and the FPGA, it can ensure a trigger decision in proper time and with satisfactory performances.

Muon trackers for imaging a nuclear reactor

NASA Astrophysics Data System (ADS)

Kume, N.; Miyadera, H.; Morris, C. L.; Bacon, J.; Borozdin, K. N.; Durham, J. M.; Fuzita, K.; Guardincerri, E.; Izumi, M.; Nakayama, K.; Saltus, M.; Sugita, T.; Takakura, K.; Yoshioka, K.

2016-09-01

A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. The system consists of a pair of drift-tube tracking detectors of 7.2× 7.2-m2 area. Each muon tracker consists of 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-μ Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when the core is imaged from outside the reactor building.

Fast Deep Tracking via Semi-Online Domain Adaptation

NASA Astrophysics Data System (ADS)

Li, Xiaoping; Luo, Wenbing; Zhu, Yi; Li, Hanxi; Wang, Mingwen

2018-04-01

Deep tracking has been illustrating overwhelming superiorities over the shallow methods. Unfortunately, it also suffers from low FPS rates. To alleviate the problem, a number of real-time deep trackers have been proposed via removing the online updating procedure on the CNN model. However, the absent of the online update leads to a significant drop on tracking accuracy. In this work, we propose to perform the domain adaptation for visual tracking in two stages for transferring the information from the visual tracking domain and the instance domain respectively. In this way, the proposed visual tracker achieves comparable tracking accuracy to the state-of-the-art trackers and runs at real-time speed on an average consuming GPU.

Feedback from video for virtual reality Navigation

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

Tsap, L V

2000-10-27

Important preconditions for wide acceptance of virtual reality (VR) systems include their comfort, ease and naturalness to use. Most existing trackers super from discomfort-related issues. For example, body-based trackers (hand controllers, joysticks, helmet attachments, etc.) restrict spontaneity and naturalness of motion, while ground-based devices (e.g., hand controllers) limit the workspace by literally binding an operator to the ground. There are similar problems with controls. This paper describes using real-time video with registered depth information (from a commercially available camera) for virtual reality navigation. Camera-based setup can replace cumbersome trackers. The method includes selective depth processing for increased speed, and amore » robust skin-color segmentation for accounting illumination variations.« less

P-Type Silicon Strip Sensors for the new CMS Tracker at HL-LHC

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

Adam, W.; Bergauer, T.; Brondolin, E.

The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. Furthermore, this paper describes the main measurement results and conclusions thatmore » motivated this decision.« less

Advanced application flight experiments precision attitude determination system. Volume 2: System tests

NASA Technical Reports Server (NTRS)

1976-01-01

The performance capability of each of two precision attitude determination systems (PADS), one using a strapdown star tracker, and the other using a single-axis gimbal star tracker was measured in the laboratory under simulated orbit conditions. The primary focus of the evaluation was on the contribution to the total system accuracy by the star trackers, and the effectiveness of the software algorithms in functioning with actual sensor signals. A brief description of PADS, the laboratory test configuration and the test facility, is given along with a discussion of the data handling and display, laboratory computer programs, PADS performance evaluation programs, and the strapdown and gimbal system tests. Results are presented and discussed.

Semiconductor liquid crystal composition and methods for making the same

DOEpatents

Alivisatos, A. Paul; Li, Liang-shi

2005-04-26

Semiconductor liquid crystal compositions and methods for making such compositions are disclosed. One embodiment of the invention is directed to a liquid crystal composition including a solvent and semiconductor particles in the solvent. The solvent and the semiconductor particles are in an effective amount in the liquid crystal composition to form a liquid crystal phase.

Integrated three-dimensional module heat exchanger for power electronics cooling

DOEpatents

Bennion, Kevin; Lustbader, Jason

2013-09-24

Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

Tuning and synthesis of semiconductor nanostructures by mechanical compression

DOEpatents

Fan, Hongyou; Li, Binsong

2015-11-17

A mechanical compression method can be used to tune semiconductor nanoparticle lattice structure and synthesize new semiconductor nanostructures including nanorods, nanowires, nanosheets, and other three-dimensional interconnected structures. II-VI or IV-VI compound semiconductor nanoparticle assemblies can be used as starting materials, including CdSe, CdTe, ZnSe, ZnS, PbSe, and PbS.

Photoelectrochemical cell including Ga(Sb.sub.x)N.sub.1-x semiconductor electrode

DOEpatents

Menon, Madhu; Sheetz, Michael; Sunkara, Mahendra Kumar; Pendyala, Chandrashekhar; Sunkara, Swathi; Jasinski, Jacek B.

2017-09-05

The composition of matter comprising Ga(Sb.sub.x)N.sub.1-x where x=0.01 to 0.06 is characterized by a band gap between 2.4 and 1.7 eV. A semiconductor device includes a semiconductor layer of that composition. A photoelectric cell includes that semiconductor device.

Method of passivating semiconductor surfaces

DOEpatents

Wanlass, M.W.

1990-06-19

A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

Surface preparation of substances for continuous convective assembly of fine particles

DOEpatents

Rossi, Robert

2003-01-01

A method for producing periodic nanometer-scale arrays of metal or semiconductor junctions on a clean semiconductor substrate surface is provided comprising the steps of: etching the substrate surface to make it hydrophilic, forming, under an inert atmosphere, a crystalline colloid layer on the substrate surface, depositing a metal or semiconductor material through the colloid layer onto the surface of the substrate, and removing the colloid from the substrate surface. The colloid layer is grown on the clean semiconductor surface by withdrawing the semiconductor substrate from a sol of colloid particles.

High resolution three-dimensional doping profiler

DOEpatents

Thundat, Thomas G.; Warmack, Robert J.

1999-01-01

A semiconductor doping profiler provides a Schottky contact at one surface and an ohmic contact at the other. While the two contacts are coupled to a power source, thereby establishing an electrical bias in the semiconductor, a localized light source illuminates the semiconductor to induce a photocurrent. The photocurrent changes in accordance with the doping characteristics of the semiconductor in the illuminated region. By changing the voltage of the power source the depth of the depletion layer can be varied to provide a three dimensional view of the local properties of the semiconductor.

Methods for enhancing P-type doping in III-V semiconductor films

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

Liu, Feng; Stringfellow, Gerald; Zhu, Junyi

2017-08-01

Methods of doping a semiconductor film are provided. The methods comprise epitaxially growing the III-V semiconductor film in the presence of a dopant, a surfactant capable of acting as an electron reservoir, and hydrogen, under conditions that promote the formation of a III-V semiconductor film doped with the p-type dopant. In some embodiments of the methods, the epitaxial growth of the doped III-V semiconductor film is initiated at a first hydrogen partial pressure which is increased to a second hydrogen partial pressure during the epitaxial growth process.

Method of transferring a thin crystalline semiconductor layer

DOEpatents

Nastasi, Michael A [Sante Fe, NM; Shao, Lin [Los Alamos, NM; Theodore, N David [Mesa, AZ

2006-12-26

A method for transferring a thin semiconductor layer from one substrate to another substrate involves depositing a thin epitaxial monocrystalline semiconductor layer on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the thin semiconductor layer is bonded to a second substrate and the thin layer is separated away at the interface, which results in transferring the thin epitaxial semiconductor layer from one substrate to the other substrate.

Reflection technique for thermal mapping of semiconductors

DOEpatents

Walter, Martin J.

1989-06-20

Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

Capital investment in semiconductors: The lifeblood of the US semiconductor industry

NASA Astrophysics Data System (ADS)

Finan, William F.

1990-09-01

An analysis is given of four proposals designed to improve capital formation for U.S. industry in general, and the semiconductor industry in particular. The National Advisory Committee on Semiconductors recommendations were to make the current research and experimentation (R and E) tax credit more effective, to reduce taxes on capital gains, to increase personal savings incentives, and to improve semiconductor manufacturing equipment depreciation rules. The results of the qualitative analysis of the proposals as well as a description of the methodology employed are given.

Method of passivating semiconductor surfaces

DOEpatents

Wanlass, Mark W.

1990-01-01

A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

Method and apparatus for use of III-nitride wide bandgap semiconductors in optical communications

DOEpatents

Hui, Rongqing [Lenexa, KS; Jiang, Hong-Xing [Manhattan, KS; Lin, Jing-Yu [Manhattan, KS

2008-03-18

The present disclosure relates to the use of III-nitride wide bandgap semiconductor materials for optical communications. In one embodiment, an optical device includes an optical waveguide device fabricated using a III-nitride semiconductor material. The III-nitride semiconductor material provides for an electrically controllable refractive index. The optical waveguide device provides for high speed optical communications in an infrared wavelength region. In one embodiment, an optical amplifier is provided using optical coatings at the facet ends of a waveguide formed of erbium-doped III-nitride semiconductor materials.