Dr. Tirupati Kumara Sridharan Profile

Dr. Tirupati Kumara Sridharan

Scientist/Astronomer at National Radio Astronomy Observatory

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 11 September 2024 Presentation + Paper

Presentation + Paper

Advanced metrology sensor applications for improved pointing performance of the Greenland Telescope

Nimesh Patel, Pierre Martin-Cocher, Philippe Raffin, George Nystrom, Satoki Matsushita, Chih-Wei Huang, Klaus Willmeroth, Teddy Huang, Derek Kubo, Jun-Yi Koay, Cristina Romero-Canizales, Keiichi Asada, Ming-Tang Chen, Johnson Han, Paul T. Ho, Timothy Norton, T. Sridharan

Proceedings Volume 13094, 130940G (2024) https://doi.org/10.1117/12.3019144

KEYWORDS: Sensors, Antennas, Temperature sensors, Metrology, Telescopes, Receivers, Wind speed, Data modeling

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Proceedings Article | 26 August 2024 Presentation + Paper

Presentation + Paper

Ultra-low-noise laser and optical frequency comb-based timing system for the Black Hole Explorer (BHEX) mission

Hannah Tomio, Guangning Yang, Holly Leopardi, Kenji Numata, Anthony Yu, Andrew Attar, Xiaozhen Xu, Wei Lu, Cheryl Gramling, T. Sridharan, Peter Kurczynski

Proceedings Volume 13100, 131000O (2024) https://doi.org/10.1117/12.3020732

KEYWORDS: Laser frequency, Laser stabilization, Frequency combs, Laser optics, Microwave radiation, Laser development, Telescopes, Astronomical telescopes, Astronomical interferometers

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Proceedings Article | 23 August 2024 Presentation + Paper

Presentation + Paper

The Black Hole Explorer: instrument system overview

Daniel Marrone, Janice Houston, Kazunori Akiyama, Bryan Bilyeu, Don Boroson, Paul Grimes, Kari Haworth, Robert Lehmensiek, Eliad Peretz, Hannah Rana, Laura Sinclair, Sridharan Tirupati Kumara, Ranjani Srinivasan, Edward Tong, Jade Wang, Jonathan Weintroub, Michael Johnson

Proceedings Volume 13092, 130922G (2024) https://doi.org/10.1117/12.3019589

KEYWORDS: Telescopes, Receivers, Design, Radio interferometry, Laser communications, Optical clocks

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Proceedings Article | 23 August 2024 Poster + Paper

Poster + Paper

The Black Hole Explorer (BHEX): preliminary antenna design

T. Sridharan, R. Lehmensiek, D. Marrone, P. Cheimets, M. Freeman, P. Galison, J. Houston, M. Johnson, M. Silver

Proceedings Volume 13092, 130926S (2024) https://doi.org/10.1117/12.3020504

KEYWORDS: Antennas, Design, Reflectors, Carbon fiber reinforced plastics, Spatial resolution, Telescopes, Physics, Optical design

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Proceedings Article | 23 August 2024 Presentation + Paper

Presentation + Paper

The Black Hole Explorer: astrophysics mission concept engineering study report

Eliad Peretz, Peter Kurczynski, Michael Johnson, Janice Houston, Tirupati Kumara Sridharan, Jade Wang, Peter Galison, Ronald Gamble, Daniel Marrone, Scott Noble, Gary Melnick, Leonid Petrov, Hannah Rana, Kari Haworth, Sheperd Doeleman, Sara Issaoun, Shahar Hadar, Alexandru Lupsasca, Edward Tong, Kazunori Akiyama, Ranjani Srinivasan, Dan Boroson, Guangning Yang, Tiffany Hoerbelt, Jeffrey Small, Mareki Honma, Bryan Bilyeu, Ed Canavan, Katia Shtyrkova, Robert Lafon, Lenny Paritsky, Laura Sinclair, Mark Silver, Leonid Gurvits, Yuri Kovalev, Robert Lehmensiek, Hua Jiao, Lindy Blackburn, Alexandra Brosius, Rick Butler, Andrew Chael, Dominic Chang, Koushik Chatterjee, Peter Cheimets, Daniel D'Orazio, Thomas Essinger-Hileman, Vincent Fish, Garret Fitzpatrick, Charles Gammie, Zachary Gelles, Michael Hecht, Jens Kauffmann, Jared Lucey, Chung-Pei Ma, Mark Matsumura, Daniel Palumbo, Dominic Pesce, Jeff Piepmeier, Christopher Roberts, Freek Roelofs, Paul Tiede, Jaye Verniero, Maciek Wielgus, Ed Wollack, George Wong, Kelsey Gilchrist, Kayla Carmical, Andrew Lewis, Maya Wertheim, Keshet Shavit

Proceedings Volume 13092, 130922F (2024) https://doi.org/10.1117/12.3019010

KEYWORDS: Antennas, Engineering, Telescopes, Laser frequency, Design, Oscillators, Optical clocks, Data transmission, Optical communications, Clocks

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Proceedings Article | 23 August 2024 Presentation + Paper

Presentation + Paper

The Black Hole Explorer: motivation and vision

Michael Johnson, Kazunori Akiyama, Rebecca Baturin, Bryan Bilyeu, Lindy Blackburn, Don Boroson, Alejandro Cárdenas-Avendaño, Andrew Chael, Chi-kwan Chan, Dominic Chang, Peter Cheimets, Cathy Chou, Sheperd Doeleman, Joseph Farah, Peter Galison, Ronald Gamble, Charles Gammie, Zachary Gelles, José Gómez, Samuel Gralla, Paul Grimes, Leonid Gurvits, Shahar Hadar, Kari Haworth, Kazuhiro Hada, Michael Hecht, Mareki Honma, Janice Houston, Ben Hudson, Sara Issaoun, He Jia, Svetlana Jorstad, Jens Kauffman, Yuri Kovalev, Peter Kurczynski, Robert Lafon, Alexandru Lupsasca, Robert Lehmensiek, Chung-Pei Ma, Daniel Marrone, Alan Marscher, Gary Melnick, Ramesh Narayan, Kotaro Niinuma, Scott Noble, Eric Palmer, Daniel C. Palumbo, Lenny Paritsky, Eliad Peretz, Dominic Pesce, Alexander Plavin, Eliot Quataert, Hannah Rana, Angelo Ricarte, Freek Roelofs, Katia Shtyrkova, Laura Sinclair, Jeffrey Small, Sridharan Tirupati Kumara, Ranjani Srinivasan, Andrew Strominger, Paul Tiede, Edward Tong, Jade Wang, Jonathan Weintroub, Maciek Wielgus, George Wong

Proceedings Volume 13092, 130922D (2024) https://doi.org/10.1117/12.3019835

KEYWORDS: Telescopes, Galactic astronomy, Spatial resolution, Shadows

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Proceedings Article | 27 August 2022 Presentation + Paper

Presentation + Paper

The Event Horizon Explorer mission concept

Peter Kurczynski, Michael Johnson, Sheperd Doeleman, Kari Haworth, Eliad Peretz, Tirupati Kumara Sridharan, Byran Bilyeu, Lindy Blackburn, Don Boroson, Alexandra Brosius, Richard Butler, Dave Caplan, Koushik Chatterjee, Peter Cheimets, Daniel D'Orazio, Thomas Essinger-Hileman, Peter Galison, Ronald Gamble, Shahar Hadar, Tiffany Hoerbelt, Hua Jiao, Jens Kauffmann, Robert Lafon, Chung-Pei Ma, Gary Melnick, Nathan Newbury, Scott Noble, Daniel Palumbo, Lenny Paritsky, Dominic Pesce, Leonid Petrov, Jeff Piepmeier, Christopher Roberts, Bryan Robinson, Curt Shieler, Jeffrey Small, Neal Spellmeyer, Paul Tiede, Jaye Verniero, Jade Wang, Maciek Wielgus, Ed Wollack, George Wong, Guangning Yang

Proceedings Volume 12180, 121800M (2022) https://doi.org/10.1117/12.2630313

KEYWORDS: Space operations, Antennas, Spatial resolution, Astrophysics, Astronomical telescopes, Telescopes, Optical communications, Laser communications, Physics, Interferometry

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Proceedings Article | 13 December 2020 Poster + Paper

Poster + Paper

Control and monitoring software for the Greenland Telescope

Chih-Wei Locutus Huang, Satoki Matsushita, Nimesh Patel, Ranjani Srinivasan, Keiichi Asada, Geoffrey Bower, Shu-Hao Chang, Chung-Cheng Chen, Ming-Tang Chen, Ryan Chilson, Chih-Chiang Han, Paul T. Ho, Yau-De Huang, Makoto Inoue, Homin Jiang, Jun Yi Koay, Patrick Koch, Shoko Koyama, Derek Kubo, Cheng-Yu Kuo, Chao-Te Li, Ching-Tang Liu, Kuan-Yu Liu, Wen-Ping Lo, Pierre Martin-Cocher, Masanori Nakamura, Timothy Norton, George Nystrom, Peter Oshiro, Jongho Park, Hung-Yi Pu, Philippe Raffin, Ramprasad Rao, Cristina Romero-Cañizales, Paul Shaw, T. Sridharan, Ta-Shun Wei, Chen-Yu Yu

Proceedings Volume 11452, 114521S (2020) https://doi.org/10.1117/12.2561430

KEYWORDS: Telescopes, Control systems, Telecommunications, Interfaces, Receivers, Radio telescopes, Interferometry, Antennas, Adaptive control, Databases

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

Status of scientific commissioning of the Greenland Telescope

Jun Yi Koay, Satoki Matsushita, Keiichi Asada, Nimesh Patel, Chih-Wei Huang, Geoffrey Bower, Shu-Hao Chang, Ming-Tang Chen, Chung-Cheng Chen, Ryan Chilson, Chih-Chiang Han, Paul T. Ho, Yau-De Huang, Makoto Inoue, Homin Jiang, Patrick Koch, Shoko Koyama, Cheng-Yu Kuo, Derek Kubo, Chao-Te Li, Ching-Tang Liu, Kuan-Yu Liu, Wen-Ping Lo, Pierre Martin-Cocher, Masanori Nakamura, Timothy Norton, George Nystrom, Peter Oshiro, Jongho Park, Hung-Yi Pu, Philippe Raffin, Ramprasad Rao, Cristina Romero-Canizales, Paul Shaw, Tirupati Sridharan, Ranjani Srinivasan, Ta-Shun Wei, Chen-Yu Yu

Proceedings Volume 11445, 114450Q (2020) https://doi.org/10.1117/12.2561491

KEYWORDS: Telescopes, Atmospheric modeling, Antennas, Refraction, Photogrammetry

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Proceedings Article | 6 July 2018 Paper

Paper

Commissioning status of the Greenland Telescope (GLT)

Satoki Matsushita, Keiichi Asada, Makoto Inoue, Hiroaki Nishioka, Chih-Wei Huang, Nimesh Patel, Jun Yi Koay, Shoko Koyama, Patrick Koch, Zheng Meyer-Zhao, Lupin C.-C. Lin, Paul T. Ho, Ming-Tang Chen, Timothy Norton, Kuan-Yu Liu, Chen-Yu Yu, Do-Young Byun, Juan-Carlos Algaba Marcos, Alex Allardi, Geoffrey Bower, Shu-Hao Chang, Chung-Chen Chen, Ryan Chilson, Aaron Faber, Chih-Chiang Han, Yau-De Huang, Homin Jiang, Derek Kubo, Ching-Tang Liu, Wen-Ping Lo, Pierre Martin-Cocher, Masanori Nakamura, George Nystrom, Peter Oshiro, Hung-Yi Pu, Philippe Raffin, Paul Shaw, Williams Snow, Ranjani Srinivasan, Ta-Shun Wei, Ryan Berthold, Daniel Bintley, Jessica Dempsey, Per Friberg, Craig Walther, Jonathan Weintroub, André Young, Ken Young, T. Sridharan, Sheperd Doeleman, Roger Brissenden, Hideo Ogawa, Kimihiro Kimura, Yutaka Hasegawa, Jinchi Hao, Kou-Chang Han, Song-Chu Chang, Li-Ming Lu

Proceedings Volume 10700, 1070029 (2018) https://doi.org/10.1117/12.2310046

KEYWORDS: Receivers, Telescopes, Antennas, Astronomy, Observatories, Radio optics, Radio astronomy, Radio interferometry, Submillimeter telescopes

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Proceedings Article | 6 July 2018 Presentation + Paper

Presentation + Paper

The Greenland telescope: Thule operations

Ming-Tang Chen, Philippe Raffin, Paul T. Ho, Makoto Inoue, Ching-Tang Liu, Yau-De Huang, Chih-Chiang Han, Timothy Norton, Satoki Matsushita, Keiichi Asada, George Nystrom, Derek Kubo, Nimesh Patel, Shu-Hao Chang, Ta-Shun Wei, Pierre Martin-Cocher, Homin Jiang, Paul Shaw, Hiroaki Nishioka, Chih-Wei L. Huang, Chung-Chen Chen, Patrick Koch, Ryan Chilson, Ranjani Srinivasan, Kuan-Yu Liu, Chen-Yu Yu, Geoffrey Bower, Peter Oshiro, William Snow, Shoko Koyama, Jun Yi Koay, Chao-Te Li, Wen-Ping Lo, Chih-Cheng Chang, Masanori Nakamura, Zheng Meyer-Zhao, Hung-Yi Pu, Lupin Lin, Daniel Bintley, Craig Walther, Per Friberg, Jessica Dempsey, T. Sridharan, Sheperd Doeleman, Roger Brissenden, Hideo Ogawa, Kimihiro Kimura, Yutaka Hasegawa, Jinchi Hao, Kuo-Chang Han, Song-Chu Chang, Li-Ming Lu, Juan-Carlos Algaba Marcos, Alex Allardi, Aaron Faber, Fu-li Hsu, Wei-Long Chen, Fang-Chia Hsieh

Proceedings Volume 10700, 107000H (2018) https://doi.org/10.1117/12.2313378

KEYWORDS: Antennas, Telescopes, Receivers, Observatories, Astronomy, Astrophysics

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Proceedings Article | 27 July 2016 Paper

Paper

The Greenland Telescope: antenna retrofit status and future plans

Philippe Raffin, Paul T. Ho, Keiichi Asada, Raymond Blundell, Geoffrey Bower, Roberto Burgos, Chih-Cheng Chang, Ming-Tang Chen, Robert Christensen, You-Hua Chu, Paul Grimes, C. Han, Chih-Wei Huang, Yau-De Huang, Fang-Chia Hsieh, Makoto Inoue, Patrick Koch, Derek Kubo, Steve Leiker, Lupin Lin, Ching-Tang Liu, Shih-Hsiang Lo, Pierre Martin-Cocher, Satoki Matsushita, Masanori Nakamura, Zheng Meyer-Zhao, Hiroaki Nishioka, Tim Norton, George Nystrom, Scott Paine, Nimesh Patel, Hung-Yi Pu, William Snow, T. Sridharan, Ranjani Srinivasan, Jackie Wang

Proceedings Volume 9906, 99060U (2016) https://doi.org/10.1117/12.2232889

KEYWORDS: Antennas, Telescopes, Reflectors, Astrophysics, Electronics, Receivers, Space telescopes, Servomechanisms, 3D modeling, Foam

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Proceedings Article | 23 July 2014 Paper

Paper

Vector near-field beam scanner for the SMA

Robert Christensen, Ramprasad Rao, T. Sridharan, Edward Tong

Proceedings Volume 9153, 915330 (2014) https://doi.org/10.1117/12.2057124

KEYWORDS: Receivers, Mirrors, Scanners, Antennas, Shape memory alloys, Transmitters, Polarization, Near field, Astronomy, Near field optics

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Proceedings Article | 23 July 2014 Paper

Paper

Instrumentation for single-dish observations with The Greenland Telescope

Paul Grimes, K. Asada, R. Blundell, R. Burgos, H-H. Chang, M. Chen, D. Goldie, C. Groppi, C. Han, P. T. Ho, Y. Huang, M. Inoue, D. Kubo, P. Koch, J. Leech, E. de Lera Acedo, P. Martin-Cocher, H. Nishioka, M. Nakamura, S. Matsushita, S. Paine, N. Patel, P. Raffin, W. Snow, T. Sridharan, R. Srinivasan, C. Thomas, E. Tong, M.-J. Wang, C. Wheeler, S. Withington, G. Yassin, L.-Z. Zeng

Proceedings Volume 9153, 91531V (2014) https://doi.org/10.1117/12.2056969

KEYWORDS: Antennas, Telescopes, Terahertz radiation, Prototyping, Galactic astronomy, Astronomy, Heterodyning, Receivers, Field programmable gate arrays, Observatories

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The Greenland Telescope project will deploy and operate a 12m sub-millimeter telescope at the highest point of the Greenland i e sheet. The Greenland Telescope project is a joint venture between the Smithsonian As- trophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). In this paper we discuss the concepts, specifications, and science goals of the instruments being developed for single-dish observations with the Greenland Telescope, and the coupling optics required to couple both them and the mm-VLBI receivers to antenna. The project will outfit the ALMA North America prototype antenna for Arctic operations and deploy it to Summit Station,1 a NSF operated Arctic station at 3,100m above MSL on the Greenland I e Sheet. This site is exceptionally dry, and promises to be an excellent site for sub-millimeter astronomical observations. The main science goal of the Greenland Telescope is to carry out millimeter VLBI observations alongside other telescopes in Europe and the Americas, with the aim of resolving the event horizon of the super-massive black hole at the enter of M87. The Greenland Telescope will also be outfitted for single-dish observations from the millimeter-wave to Tera-hertz bands. In this paper we will discuss the proposed instruments that are currently in development for the Greenland Telescope - 350 GHz and 650 GHz heterodyne array receivers; 1.4 THz HEB array receivers and a W-band bolometric spectrometer. SAO is leading the development of two heterodyne array instruments for the Greenland Telescope, a 48- pixel, 325-375 GHz SIS array receiver, and a 4 pixel, 1.4 THz HEB array receiver. A key science goal for these instruments is the mapping of ortho and para H2D+ in old protostellar ores, as well as general mapping of CO and other transitions in molecular louds. An 8-pixel prototype module for the 350 GHz array is currently being built for laboratory and operational testing on the Greenland Telescope. Arizona State University are developing a 650 GHz 256 pixel SIS array receiver based on the KAPPa SIS mixer array technology and ASIAA are developing 1.4 THz HEB single pixel and array receivers. The University of Cambridge and SAO are collaborating on the development of the CAMbridge Emission Line Surveyor (CAMELS), a W-band `on- hip' spectrometer instrument with a spectral resolution of R ~ 3000. CAMELS will consist of two pairs of horn antennas, feeding super conducting niobium nitride filter banks read by tantalum based Kinetic Inductance Detectors.

Proceedings Article | 22 July 2014 Paper

Paper

The Greenland Telescope (GLT): antenna status and future plans

Philippe Raffin, Juan Carlos Algaba-Marcosa, Keiichi Asada, Raymond Blundell, Roberto Burgos, Chih-Cheng Chang, Ming-Tang Chen, Robert Christensen, Paul Grimes, C. Han, Paul T. Ho, Yau-De Huang, Makoto Inoue, Patrick Koch, Derek Kubo, Steve Leiker, Ching-Tang Liu, Pierre Martin-Cocher, Satoki Matsushita, Masanori Nakamura, Hiroaki Nishioka, George Nystrom, Scott Paine, Nimesh Patel, Nicolas Pradel, Hung-Yi Pu, H.-Y. Shen, William Snow, Tirupati Sridharan, Ranjani Srinivasan, Edward Tong, Jackie Wang

Proceedings Volume 9145, 91450G (2014) https://doi.org/10.1117/12.2056836

KEYWORDS: Antennas, Telescopes, Inspection, Prototyping, Servomechanisms, Computer programming, Manufacturing, Carbon, Reflectors, Astrophysics

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Proceedings Article | 27 June 2006 Paper

Paper

Elevation angle dependence of the SMA antenna focus position

Satoki Matsushita, Masao Saito, Kazushi Sakamoto, Todd Hunter, Nimesh Patel, Tirupati Sridharan, Robert Wilson

Proceedings Volume 6275, 62751W (2006) https://doi.org/10.1117/12.670642

KEYWORDS: Antennas, Shape memory alloys, Jupiter, Reflectors, Astronomy, Radio optics, Telescopes, Planets, Oscillators, Temperature metrology

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Proceedings Article | 22 June 2006 Paper

Paper

APEX: the Atacama Pathfinder EXperiment

R. Güsten, R. Booth, C. Cesarsky, K. Menten, C. Agurto, M. Anciaux, F. Azagra, V. Belitsky, A. Belloche, P. Bergman, C. De Breuck, C. Comito, M. Dumke, C. Duran, W. Esch, J. Fluxa, A. Greve, H. Hafok, W. Häupl, L. Helldner, A. Henseler, S. Heyminck, L. Johansson, C. Kasemann, B. Klein, A. Korn, E. Kreysa, R. Kurz, I. Lapkin, S. Leurini, D. Lis, A. Lundgren, F. Mac-Auliffe, M. Martinez, J. Melnick, D. Morris, D. Muders, L. Nyman, M. Olberg, R. Olivares, M. Pantaleev, N. Patel, K. Pausch, S. Philipp, S. Philipps, T. Sridharan, E. Polehampton, V. Reveret, C. Risacher, M. Roa, P. Sauer, P. Schilke, J. Santana, G. Schneider, J. Sepulveda, G. Siringo, J. Spyromilio, K.-H. Stenvers, F. van der Tak, D. Torres, L. Vanzi, V. Vassilev, A. Weiss, K. Willmeroth, A. Wunsch, F. Wyrowski

Proceedings Volume 6267, 626714 (2006) https://doi.org/10.1117/12.670798

KEYWORDS: Telescopes, Receivers, Reflectors, Antennas, Bolometers, Space telescopes, Stars, Calibration, Heterodyning, Mirrors

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Proceedings Article | 29 September 2004 Paper

Paper

Holographic surface setting of the Sub-millimeter Array antennas

Tirupati Sridharan, Masao Saito, Nimesh Patel, Robert Christensen

Proceedings Volume 5495, (2004) https://doi.org/10.1117/12.550939

KEYWORDS: Antennas, Holography, Shape memory alloys, Near field, Astronomy, Spatial resolution, Telescopes, Receivers, Efficient operations, Optical testing

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Proceedings Article | 15 September 2004 Paper

Paper

Pointing calibration of the SMA antennas

Nimesh Patel, Tirupati Sridharan

Proceedings Volume 5496, (2004) https://doi.org/10.1117/12.549655

KEYWORDS: Radio optics, Antennas, Shape memory alloys, Stars, Calibration, Computer programming, Optical testing, Collimation, Receivers, Electroluminescence

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Showing 5 of 19 publications

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