European Conference „Meetbike“. Information

The information is devoted European Conference „Meetbike“ 3-4 April2008 in Dresden, Germany. Stronger networking of European bicycle-friendly cities and better cooperation of bike use and public transport has been considered. Results of the European Conference „MeetBike“ are presented

Evaluating the auralization of a small room in a virtual sound environment using objective room acoustic measures

To study human auditory perception in realistic environments, loudspeakerbased reproduction techniques have recently become state-of-the-art. To evaluate the accuracy of a simulation-based room auralization of a small room, objective measures were evaluated. In particular: - early-decay time (EDT) & reverberation time (T20, T30); - clarity (C7, C50, C80); - interaural cross-correlation (IACC); - speech transmission index (STI); - direct-to-reverberant ratio (DRR). Impulse responses (IRs) were measured in an IEC listening room. The room was then modeled in the room acoustics software ODEON, and the same objective measures were evaluated for auralized versions of the playback room. The auralizations were realized using higher-order ambisonics (HOA), mixed-order ambisonics (MOA), and a nearest-loudspeaker method (NL) and reproduced in a virtual sound environment

Verkehrsplanung

Verkehrsplanung hat sich von einer sektoralen Fachplanung zu einer zielorientierten, beeinflussenden räumlichen Planung entwickelt (integrierte Verkehrentwicklungsplanung). Neben der Sicherung und Verbesserung von Mobilität und Verkehr strebt diese einen nachhaltigeren Verkehr mit weniger Beeinträchtigungen und Ressourcenverbrauch an. Dargestellt werden Arbeitsmethodik, Anforderungen und Einordnung der Verkehrsplanung

Sound source localization with varying amount of visual information in virtual reality

To achieve accurate spatial auditory perception, subjects typically require personal head-related transfer functions (HRTFs) and the freedom for head movements. Loudspeaker-based virtual sound environments allow for realism without individualized measurements. To study audio-visual perception in realistic environments, the combination of spatially tracked head mounted displays (HMDs), also known as virtual reality glasses, and virtual sound environments may be valuable. However, HMDs were recently shown to affect the subjects' HRTFs and thus might influence sound localization performance. Furthermore, due to limitations of the reproduction of visual information on the HMD, audio-visual perception might be influenced. Here, a sound localization experiment was conducted both with and without an HMD and with a varying amount of visual information provided to the subjects. Furthermore, interaural time and level difference errors (ITDs and ILDs) as well as spectral perturbations induced by the HMD were analyzed and compared to the perceptual localization data. The results showed a reduction of the localization accuracy when the subjects were wearing an HMD and when they were blindfolded. The HMD-induced error in azimuth localization was found to be larger in the left than in the right hemisphere. When visual information of the limited set of source locations was provided, the localization error induced by the HMD was found to be negligible. Presenting visual information of hand-location and room dimensions showed better sound localization performance compared to the condition with no visual information. The addition of possible source locations further improved the localization accuracy. Also adding pointing feedback in form of a virtual laser pointer improved the accuracy of elevation perception but not of azimuth perception

Photodisintegration of Ultra-High-Energy Cosmic Rays revisited

Recent microscopic and phenomenological calculations of giant dipole resonances for A <= 56 nuclei are presented. The derived photodisintegration cross sections are exhaustively compared to the photonuclear data available to date. An accurate description of the data is found. Our new calculations are also compared with the previous and widely-used estimates of Puget, Stecker and Bredekamp. The present calculations also include all the possible paths down the nuclear chart. The impact on the photodisintegration of ultra-high-energy cosmic rays (UHECR) is illustrated for a Fe source with typical energies of 10^{20-21} eV. At energies around 10^20 eV, the new cross sections are found to modify the UHECR photodisintegration rates. At energies around 10^21 eV, it is recommended to solve a full reaction network to estimate the photodisintegration rate of the UHECR.Comment: 16 pages, 8 figures, accepted for publication in Astroparticle Physic