Sverre Holm
I am a professor of acoustic imaging and signal processing at the University of Oslo and an elected member of the Norwegian Academy of Technological Sciences. Our group is part of "Centre for Innovative Ultrasound Solutions (CIUS)"  a centre for researchbased innovation.
My main research interest is to understand complexity, in the sense that cosmologist and astrophysicist Martin Rees spells it out: "We can expect huge advances on three frontiers: the very small, the very large, and the very complex."
More specifically my desire is to understand the physics of wave propagation in complex media like biological tissue in the context of medical ultrasound and elastography. A special focus is on understanding why this often results in power law frequency characteristics (attenuation and dispersion), and to uncover the physical basis for noninteger (fractional) derivative descriptions of waves in these media  if indeed there is one.
Once per semester or so I am on the panel of the popular national radio show NRK P2, "Tower of Abel" answering mostly questions on acoustics in a wide sense and from time to time also commenting on the philosophy of science. I have blogged since 2010, mainly in Norwegian, but also some in English.
Apart from that I probably have too many interestes. That includes indoor positioning with ultrasound, history and philosophy of science, audio/HiFi/audio coding, and ham radio.
Research

"Waves with PowerLaw Attenuation," 2019, Springer  Classical & Continuum Physics  and ASA Press (Acoustical Society of America) series.

Lecture "Waves with PowerLaw Attenuation", 28 February 2020.


"Advantages of fractional models in dealing with real world problems," COST Action training school Istanbul, Turkey, October, 2018. I was one of nine lecturers presenting models for wave propagation and applications in medical imaging and acoustics.

Invited presentations:

"Grain shearing models and relevance beyond sediment acoustics," Acoust. Soc. Am. Conference, San Diego, Dec 2019.

"Thermodynamically viable wave equations for power law attenuation in viscoelastic media," Acoustics '17, Boston.

“Thermodynamically viable fractional wave equations for power law attenuation in viscoelastic media,” SIAM Conference on Computational Science, Atlanta, GA, 2017

Am. Inst. Ultrasound in Med., "Processing the data twice: Minimum variance as an alternative to geometrybased beamforming", New York, NY, 2016.

IEEE/OES China Ocean Acoustic Symposium, "Wave propagation in marine sediments expressed by fractional wave and diffusion equations," 2016, Harbin, China.

 Member of the Scientific Committee of the Indoor Positioning and Indoor Navigation Conference 20122017. In 2012 and 2013 I also lead industry panel debates at the IPIN conferences.
Presentations for download
 Differential arrays  from cardioid microphones to Yagi antennas (2020)
 Abel’s 1823 Paper on Fractional Derivatives (Colloquium talk, 27 Feb 2020)
 Lecture notes: From Diffraction to the Fourier Transform (ver 1.2, 2020)
 Second harmonic imaging in active sonar (2016)
 Fractional derivatives and integrals (2016)
 Fascinating wave phenomena: Where Newton and Hooke fall short (2016)
 Processing the data twice: Minimum variance as an alternative to geometrybased beamforming (2016)
 Long delayed radio echoes – 80 years with an unexplained phenomenon (2016) first heard in Oslo in 1927. See also these web pages which the Wikipedia page to some extent builds on:
 The Five Most Likely Explanations for Long Delayed Echoes  Natural explanations or aliens trying to tell us something?
 15 Possible Explanations for Long Delayed Echoes
 The Art of Writing a Scientific Paper (2015).
 See also blog with same title.
 Experience with sparse arrays (2007)
 Limited diffraction beams and a new decomposition of arbitrary annular beams (2002)
Demos and Software
 The best demonstration of a fractional derivative physical device is capacitor soakage or dielectric absorption. Here's a YouTube video showing this effect.
 Some videos showing the fractional derivative of functions like the exponential function, the power function, and the sine function. They were developed by former PhD student Vikash Pandey.
 Acoustic radiation force visualization. Notice how the force can both push as well as pull. (YouTube video by former PhD student/ PostDoc Fabrice Prieur)
 Realtime GPU simulator for ultrasound fields, "Huygens on Speed" (YouTube video by former PhD student Jon Petter Åsen)
 Theremin controlled by ultrasound rangefinder (YouTube video by Eirik Renton)
 Ultrasoundbased thermometer (YouTube video by Martin A. Brinkmann)
 Touch sensitive blackboard (YouTube video)
 Try our applet for optimization of a sparse array's layout. Can you make it to the hiscore list?
 Interactive program, Ultrasim, a Matlab toolbox for ultrasound field simulation.
 Magnitude squared coherence analysis software (Climate data).
Videos from spinoff and collaborating companies
 Elliptic Labs: Ultrasound proximity technology in Xiaomi phones, Multilayer Interaction with Touchless Gesture
 Squarehead Technology:
 Audioscope and Acoustic Camera: Wind Turbine Noise, Acoustic Leak (with Norsonic)
 Sonitor Technologies: Real Time Location Systems
The publication list from the database Cristin is not always so useful as it seems to be unable to distinguish between publications from several persons with the same name as me. Therefore it may be better to use this list.
Publications
Most cited papers
 J.F. Synnevåg, A. Austeng, and S. Holm, "Adaptive beamforming applied to medical ultrasound imaging," IEEE Trans. Ultrason., Ferroelect., Freq. Contr. (Special issue on high resolution ultrasonic imaging), vol. 54(8), Aug. 2007, pp. 16061613.
 W. Chen and S. Holm, "Fractional Laplacian timespace models for linear and nonlinear lossy media exhibiting arbitrary frequency dependency," J. Acoust. Soc. Amer., pp. 14241430, Apr. 2004.
 J.F. Synnevåg, A. Austeng, and S. Holm, ”Benefits of MinimumVariance Beamforming in Medical Ultrasound Imaging”, IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Sept. 2009.
 A. Austeng and S. Holm, "Sparse 2D Arrays for 3D Phased Array Imaging  Design Methods," IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control, Aug. 2002, pp. 10731086.
 S. Holm, B. Elgetun, G. Dahl, "Properties of the beampattern of weight and layoutoptimized sparse arrays," IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control, vol. 44, no. 5, pp. 983991, Sept. 1997.
 W.Chen and S. Holm, "Modified Szabo’s wave equation models for lossy media obeying frequency power law," J. Acoust. Soc. Amer., pp. 25702574, Nov. 2003.
 Esmonde, Harry & Holm, Sverre (2020). Fractional derivative modelling of adhesive cure. Applied Mathematical Modelling. ISSN 0307904X. 77(2), s 1041 1053 . doi: 10.1016/j.apm.2019.08.021
 Esmonde, Harry & Holm, Sverre (2020). Fractional derivative modelling of adhesive cure. Applied Mathematical Modelling. ISSN 0307904X. 77, s 1041 1053 . doi: https://doi.org/10.1016/j.apm.2019.08.021 Show summary
 Yang, Xu; Cai, Wei; Liang, Yingjie & Holm, Sverre (2020). A novel representation of timevarying viscosity with powerlaw and comparative study. International Journal of NonLinear Mechanics. ISSN 00207462. 119, s 1 10 . doi: 10.1016/j.ijnonlinmec.2019.103372
 Yang, Xu; Cai, Wei; Liang, Yingjie & Holm, Sverre (2020). A novel representation of timevarying viscosity with powerlaw and comparative study. International Journal of NonLinear Mechanics. ISSN 00207462. 119, s 103372 . doi: https://doi.org/10.1016/j.ijnonlinmec.2019.103372
 Chandrasekaran, Sri Nivas & Holm, Sverre (2019). A multiple relaxation interpretation of the extended Biot model. Journal of the Acoustical Society of America. ISSN 00014966. 146(1), s 330 339 . doi: 10.1121/1.5116139
 Holm, Sverre (2019). Dispersion analysis for wave equations with fractional Laplacian loss operators. Fractional Calculus and Applied Analysis. ISSN 13110454. 22(6), s 1596 1606 . doi: 10.1515/fca20190082
 Kvam, Johannes; Holm, Sverre & Angelsen, Bjørn Atle Johan (2019). Exploiting Ballou's rule for better tissue classification. Journal of the Acoustical Society of America. ISSN 00014966. 145(4), s 2103 2112 . doi: 10.1121/1.5096533
 Parker, Kevin; Szabo, Thomas & Holm, Sverre (2019). Towards a consensus on rheological models for elastography in soft tissues. Physics in Medicine and Biology. ISSN 00319155. 64(21) . doi: 10.1088/13616560/ab453d Show summary
 Patz, Samuel; Fovargue, Daniel; Schregel, Katharina; Nazari, Navid; Palotai, Miklos; Barbone, Paul E.; Fabry, Ben; Hammers, Alexander; Holm, Sverre; Kozerke, Sebastian; Nordsletten, David & Sinkus, Ralph (2019). Imaging localized neuronal activity at fast time scales through biomechanics. Science Advances. ISSN 23752548. 5(4) . doi: 10.1126/sciadv.aav3816 Show summary
 Evensen, Karen Brastad; O'Rourke, Michael; Prieur, Fabrice Jean Gabriel; Holm, Sverre & Eide, Per Kristian (2018). Noninvasive Estimation of the Intracranial Pressure Waveform from the Central Arterial Blood Pressure Waveform in Idiopathic Normal Pressure Hydrocephalus Patients. Scientific Reports. ISSN 20452322. 8:4714, s 1 11 . doi: 10.1038/s41598018231427
 Evensen, Karen Brastad; Paulat, Klaus; Prieur, Fabrice Jean Gabriel; Holm, Sverre & Eide, Per Kristian (2018). Utility of the Tympanic Membrane Pressure Waveform for Noninvasive Estimation of The Intracranial Pressure Waveform. Scientific Reports. ISSN 20452322. 8, s 1 11 . doi: 10.1038/s41598018340836 Full text in Research Archive.
 Holm, Sverre (2018). Spring–damper equivalents of the fractional, poroelastic, and poroviscoelastic models for elastography. NMR in Biomedicine. ISSN 09523480. 31(10), s 1 12 . doi: 10.1002/nbm.3854 Full text in Research Archive. Show summary
 Sinkus, Ralph; Lambert, Simon; AbdElmoniem, Khaled Z.; Morse, Caryn; Heller, Theo; Guenthner, Christian; Ghanem, Ahmed M.; Holm, Sverre & Gharib, Ahmed (2018). Rheological determinants for simultaneous staging of hepatic fibrosis and inflammation in patients with chronic liver disease. NMR in Biomedicine. ISSN 09523480. 31(10) . doi: 10.1002/nbm.3956 Show summary
 Wei, Cai; Chen, Wen; Fang, Jun & Holm, Sverre (2018). A Survey on Fractional Derivative Modeling of PowerLaw FrequencyDependent Viscous Dissipative and Scattering Attenuation in Acoustic Wave Propagation. Applied Mechanics Review. ISSN 00036900. 70(3) . doi: 10.1115/1.4040402 Show summary
 Bergh, Trond; Hafizovic, Ines & Holm, Sverre (2017). Acoustic imaging of sparse Sources with Orthogonal Matching Pursuit and clustering of basis vectors. Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing. ISSN 15206149. s 6030 6034 . doi: 10.1109/ICASSP.2017.7953314
 Chandrasekaran, Sri Nivas; Holm, Sverre & Prieur, Fabrice Jean Gabriel (2017). Focused ultrasound setup for the study of acoustic radiation force induced biological effects in cells. Proceedings  IEEE Ultrasonics Symposium. ISSN 19485719. . doi: 10.1109/ULTSYM.2017.8091996
 Chen, Wen; Fang, Jun; Pang, Guofei & Holm, Sverre (2017). Fractional biharmonic operator equation model for arbitrary frequencydependent scattering attenuation in acoustic wave propagation. Journal of the Acoustical Society of America. ISSN 00014966. 141(1), s 244 253 . doi: 10.1121/1.4973865 Full text in Research Archive.
 Gregersen, Ida; Sandanger, Øystein; Askevold, Erik Tandberg; Sagen, Ellen Lund; Yang, Kuan; Holm, Sverre; Pedersen, Turid Margrethe; Skjelland, Mona; KrohgSørensen, Kirsten; Hansen, Trond Vidar; Dahl, Tuva Børresdatter; Otterdal, Kari; Espevik, Terje; Aukrust, Pål; Yndestad, Arne & Halvorsen, Bente (2017). Interleukin 27 is increased in carotid atherosclerosis and promotes NLRP3 inflammasome activation.. PLOS ONE. ISSN 19326203. 12(11) . doi: 10.1371/journal.pone.0188387 Full text in Research Archive.
 Holm, Sverre & Holm, Martin Blomhoff (2017). Restrictions on wave equations for passive media. Journal of the Acoustical Society of America. ISSN 00014966. 142(4), s 1888 1896 . doi: 10.1121/1.5006059
 Prieur, Fabrice Jean Gabriel; Rindal, Ole Marius Hoel; Holm, Sverre & Austeng, Andreas (2017). Influence of the DelayMultiplyAndSum beamformer on the ultrasound image amplitude. Proceedings  IEEE Ultrasonics Symposium. ISSN 19485719. . doi: 10.1109/ULTSYM.2017.8092637
 Rindal, Ole Marius Hoel; Aakhus, Svend; Holm, Sverre & Austeng, Andreas (2017). Hypothesis of Improved Visualization of Microstructures in the Interventricular Septum with Ultrasound and Adaptive Beamforming. Ultrasound in Medicine and Biology. ISSN 03015629. 43(10), s 2494 2499 . doi: 10.1016/j.ultrasmedbio.2017.05.023
 Bergh, Trond; Hafizovic, Ines & Holm, Sverre (2016). Multispeaker voice activity detection using a cameraassisted microphone array. International Conference on Systems, Signals, and Image Processing. ISSN 21578672. 2016June . doi: 10.1109/IWSSIP.2016.7502768
 Holm, Sverre (2019). Waves with PowerLaw Attenuation. Springer Nature. ISBN 9783030149277. 312 s. Show summary
 Holm, Sverre (2020). Abel’s 1823 Paper on Fractional Derivatives and Waves with PowerLaw Attenuation. Show summary
 Holm, Sverre (2020). Waves with PowerLaw Attenuation. Show summary
 Holm, Sverre (2020). Waves with PowerLaw Attenuation. Show summary
 Aparicio, Joaquin; Alvarez, Fernando; Hernandez, Alvaro & Holm, Sverre (2019). A review of techniques for ultrasonic indoor localization systems.
 Holm, Sverre (2019). Er naturvitenskap Teorien om Alt?.
 Holm, Sverre (2019). Evolusjon og klassisk kristen tro.
 Holm, Sverre (2019). Evolusjon og klassisk kristen tro. Teistisk evolusjon ‐ Evolusjonær kreasjonisme.
 Holm, Sverre (2019). Troende naturforskere gjennom 400 år ved seks av dem.
 Holm, Sverre (2019). Troende naturforskere gjennom 400 år ved seks av dem.
 Holm, Sverre (2019). Troende naturforskere gjennom 400 år ved åtte av dem.
 Holm, Sverre (2019). Troende naturforskere gjennom 400 år ved åtte av dem.
 Chandrasekaran, Sri Nivas; Evensen, Karen Brastad; Ramsdal, Elisabeth Grønn & Holm, Sverre (2018). Integrating the BiotStoll model with contact squirt flow and shear drag (BICSQS) in the Biot viscosity extended framework. Journal of the Acoustical Society of America. ISSN 00014966. . doi: https://asa.scitation.org/doi/10.1121/1.5036507
 Chandrasekaran, Sri Nivas & Holm, Sverre (2018). Integrating the BiotStoll model with contact squirt flow and shear drag (BICSQS) in the Biot viscosity extended framework.
 Holm, Sverre (2018). Kristen tro og naturvitenskap: Troende naturforskere og fire modeller.
 Holm, Sverre (2018). Kristne vitenskapsfolk gjennom historien.
 Holm, Sverre (2018). Stephen Hawking som filosof. Avisa Vårt land. Show summary
 Holm, Sverre (2018). Vitenskap og skapertro: 8 forskere og 4 perspektiver.
 Chandrasekaran, Sri Nivas; Holm, Sverre & Prieur, Fabrice Jean Gabriel (2017). Focused ultrasound setup for the study of acoustic radiation force induced biological effects in cells. Show summary
 Holm, Sverre (2017). Det går bra med månen. Dagen : kristelig dagblad. ISSN 08054738. Show summary
 Holm, Sverre (2017). Lemfeldig omgang med naturvitenskap. Dagen : kristelig dagblad. ISSN 08054738.
 Holm, Sverre (2017). New insights from applying linear viscoelasticity to acoustics.
 Holm, Sverre (2017). Sannhet er det viktigste vi kan søke. Dagen : kristelig dagblad. ISSN 08054738.
 Holm, Sverre (2017). Thermodynamically viable fractional wave equations for power law attenuation in viscoelastic media. Show summary
 Holm, Sverre (2017). Thermodynamically viable wave equations for power law attenuation in viscoelastic media. Show summary
 Prieur, Fabrice Jean Gabriel; Rindal, Ole Marius Hoel; Holm, Sverre & Austeng, Andreas (2017). Influence of the DelayMultiplyAndSum beamformer on the ultrasound image amplitude.
 Holm, Sverre (2016). – Kristne bør ikke bli forskere, og særlig ikke innen biologi. Dagen : kristelig dagblad. ISSN 08054738. s 3 3
 Holm, Sverre (2016). Bedre alternativ enn Intelligent Design. Dagen : kristelig dagblad. ISSN 08054738. s 19 19