## Priv.-Doz. Dr. Richard Kowar

ECMI-Contact Person

E-Mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Phone: +43 512 507 53842

Address: Technikerstraße 13, 6020 Innsbruck - Austria

Room: 711a | 7^{th} floor Civil Engineer Building

## Published 2017

**Iterative Methods for Photoacoustic Tomography in Attenuating Acoustic Media**

M. Haltmeier, R. Kowar, L. V. Nguyen

Inverse Probl 33(11):115009, 2017 [pdf ] [arxiv.org]

## Published 2015

**Causality analysis of the fractional state and wave equations based on fractional Laplacians**

R. Kowar

Wave Motion 58, pp.244-258, 2015 [arxiv.org]

## Published 2014

**On time reversal in photoacoustic tomography for tissue similar to water**

R. Kowar

SIAM J Imaging Sci 7(1), pp.509-527, 2014 [arxiv.org] [pdf ]

**Time reversal for photoacoustic tomography based on the wave equation of Nachman, Smith and Waag.**

R. Kowar

Phys Rev E Stat Nonlin Soft Matter Phys 89(2):023203, 2014, [arxiv.org] [pdf ]

## Published 2013

**Analysis of a causal diffusion model and its backwards diffusion problem**

R. Kowar

J Math Anal Appl 400(1), pp.222-238, 2013 [arxiv.org]

## Published 2012 and earlier

**Small frequency approximation of (causal) dissipative pressure waves**

R. Kowar

Proc. The Fifth Symposium on Fractional Differentiation and Its Applications 2012 [arxiv.org]

**Attenuation Models in Photoacoustics**

R. Kowar, O. Scherzer

Chapter in H. Ammari (Editor); Mathematical Modeling in Biomedical Imaging II: pp.85-130, 2012 [arxiv.org]

**On the causality of real-valued semigroups and diffusion**

R. Kowar

Math Methods in the Appl Sci 35(2), pp.207-227, 2012 [arxiv.org]

### 2011

**Causality analysis of frequency-dependent wave attenuation**

R. Kowar, and O. Scherzer and X. Bonnefond

Math Methods in the Appl Sci 34(1), pp.108-124, 2011 [arxiv.org]

**Real-valued Semigroups and (Causal) Diffusion**

R. Kowar

AIP Conf Proc 1389, pp.886-888, 2011 (3 pages)

### 2010

**Integral equation models for thermoacoustic imaging of acoustic dissipative tissue**

R. Kowar

Inverse Probl. 26, 2010 [arxiv.org]

### 2009

**Causality analysis of waves and wave equations obeying attenuation**

R. Kowar

Research Report: Network FWF S105: Photoacoustic Imaging in Medicine and Biology, 2009, 6, January [arxiv.org]

### 2007

**Kaczmarz methods for regularizing nonlinear ill-posed equations II: Applications**

M. Haltmeier, R. Kowar, A. Leitao, O. Scherzer

Inverse Probl Imaging 1(3), pp.507-523, 2007

### 2006

**Computer aided location of avalanche victims with ground penetrating radar mounted on a helicopter**

M. Haltmeier, R. Kowar, O. Scherzer

Proc. 30^{th}Workshop of the Austrian Association for Pattern Recognition, pp.65-74, 2006 [pdf ]

**Reconstruction of Transducer Pressure Fields from Schlieren Data**

R. Kowar

Proc. ECMI 2006, 2006

**Rapid location of avalanche victims with ground penetrating radar**

M. Haltmeier, R. Kowar

ECMI-Newsletter 39, pp.31-33, 2006

### 2005

**Estimation of the density, the wave speed and the acoustic impedance function in ultrasound imaging**

R. Kowar

Inverse Probl. 21, pp.93-112, 2005

### 2004

**Numerical estimation of the acoustic impedance function of nonhomogeneous media**

R. Kowar

Proc. ECCOMAS 2004, 2004