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Proceedings of the ICA 2019 and EAA Euroregio : 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019 : 9-13 September 2019, Aachen, Germany / proceedings editor: Martin Ochmann, Michael Vorländer, Janina Fels 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019, ICA 2019, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019; Aachen (2019)., Published by Aachen

Proceedings of the ICA 2019 and EAA Euroregio : 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019 : 9-13 September 2019, Aachen, Germany / proceedings editor: Martin Ochmann, Michael Vorländer, Janina Fels 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019, ICA 2019, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019; Aachen (2019)., Published by Aachen

Proceedings of the ICA 2019 and EAA Euroregio : 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019 : 9-13 September 2019, Aachen, Germany / proceedings editor: Martin Ochmann, Michael Vorländer, Janina Fels 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019, ICA 2019, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019; Aachen (2019)., Published by Aachen

Temperature, secchi depth, and chlorophyll-a (in relation to secchi depth) of Zinav Lake in Turkey were modeled and mapped by using Geographic Information Systems (GIS) and Remote Sensing (RS). Temperature (oC), secchi depth (m), and chlorophyll-a (mg/l) field data were collected from geo-referenced 5 stations on the lake between September- 2011 and October-2012 in monthly basis. Secchi depth was measured by Hidrobios brand secchi disc with 25 cm diameter. A multi-measuring device (YSI-556MPS) was utilized to determine temperature values. Chlorophyll-a was measured by using Helios-α model UV-Vis spectrophotometer and monochromatic method. Utilizing geo-referenced field data and the digital number (DN) values of thermal (6.1) band of Landsat-7 ETM+ image (date: 27 April 2012 and pat/row: 175/32), temperature raster map of Zinav Lake was created. Relationships between secchi depth and band1/band3 values of Landsat-7 ETM+ image, and between secchi depth and chlorophyll-a were modeled by curve fit analysis. Running the produced models in GIS, secchi depth, temperature and chlorophyll-a raster maps of Zinav Lake were generated. The results showed that the lake has anoxic conditions and it exhibits eutrophic characters.

Visible Light Communication(VLC) has been considered as a potential access option for 5G wireless systems to solve performance limitation due to bandwidth shortage at radio frequency (RF) band. In (VLC) system, illumination infrastructure has dual usage at the same time namely illumination and wireless data transmission. DC Biased optical (DCO)-OFDM has been proposed for VLC systems to provide optically power efficient solution and easy implementation. Wireless communication systems generally require estimating and tracking the fading channel in order to detect transmitted data coherently. In this work, comb type pilot arrangement with interpolation and block type pilot arrangement are proposed for the DCO-OFDM systems over visible light channels. Simulation results have verified that the proposed block type pilot arrangement based channel estimation has clear BER performance advantages compared with comb type pilot arrangement based channel estimation.

Diese Arbeit befasste sich mit den Fragen, wie sich einerseits ein Vertrauensschock in Folge einer unerwarteten Zwangssteuer und andererseits Feedback über erfolgte Steuerprüfungen auf die Steuerehrlichkeit auswirken. Als theoretisches Modell wurde das Slippery Slope Framework herangezogen. In einem computergestützten Steuerexperiment wurden insgesamt 126 Studierende verschiedener Studienrichtungen über 22 Runden bei der Steuerabgabe ihres experimentellen Einkommens beobachtet. Die Prüfwahrscheinlichkeit (ca. 15%) sowie die Höhe der Strafe (Nachzahlung des hinterzogenen Betrags mal zwei) war den TeilnehmerInnen bekannt. Ergänzend wurden Einstellungen zu Steuern und zum Experiment sowie demographische Daten der TeilnehmerInnen erhoben. Das Steuerexperiment war als 2 (Einbußen/Zwangssteuer) x 2 (Feedback/Verzögertes Feedback) Design mit Messwiederholungen konzipiert. Um das Vertrauen in die Behörde zu manipulieren, mussten zwar alle TeilnehmerInnen in bestimmten Runden einen finanziellen Verlust hinnehmen, zwei Gruppen (Einbußen) bekamen dazu jedoch eine neutrale Erklärung, in den anderen zwei Gruppen (Zwangssteuer) erhob der „Staat…eine verbindliche Zusatzsteuer“. Um das Feedback seitens der Behörden zu untersuchen, wurden zwei Versuchsgruppen (Feedback) nach jeder Runde über eine erfolgte Steuerprüfung informiert, zwei weitere (Verzögertes Feedback) erst am Ende des Experimentes. Wie in anderen Studien konnte nachgewiesen werden, dass die Feedback-Gruppen unabhängig vom gezeigten „Bomb Crater“ Effekt signifikant mehr Steuern hinterzogen als die Verzögertes Feedback-Gruppen. Die unerwartete Zwangssteuer als Manipulation des Vertrauens hatte hingegen weder einen signifikanten Einfluss auf das wahrgenommene Vertrauen noch auf die Steuerehrlichkeit der TeilnehmerInnen. Die Ergebnisse lassen in Bezug auf das Slippery Slope Framework keine klaren Schlüsse zu, werfen aber neben beobachteten Auffälligkeiten im Steuerverhalten interessante Fragen auf., The present study investigated how tax compliance according to the slippery slope framework is influenced by (1) a shock to trust induced by a compulsory tax and (2) immediate feedback on audits. Therefore a computer-aided experiment was conducted to collect behavioral data from 126 university students receiving experimental income and reporting taxes in 22 rounds while being aware of audit probability (approximately 15%) and fines (two times the evaded amount). Participants were randomly assigned to the conditions of a 2 (compulsory tax/income drop) x 2 (immediate feedback/delayed feedback) between-subjects design. While all participants suffered the same financial losses in certain rounds, some participants were informed that the authorities had kept part of the income as additional tax, the others were told about a change in income. The second manipulation separated the sample by either providing feedback on audits after every round or only once at the end of the experiment. In addition, each participant filled in a questionnaire regarding attitudes towards the experiment and tax in general. As shown in other experiments immediate feedback resulted in significantly higher tax evasion than delayed feedback, even after excluding rounds affected by the bomb crater effect. The compulsory tax was not perceived as a shock to trust and led to equal tax compliance as the income drop. The results may be ambiguous in terms of the slippery slope framework, but tendencies as well as anomalies in tax behavior raise interesting questions.

More than three decades ago, Anderson and Hampton [1980a, 1980b] (A&H) presented the theories for wave propagation in gassy water, saturated sediments and gassy sediments in their two-part review, which has been cited by many researchers in the geoacoustics and underwater acoustics areas. They gave an empirical formulation based on the theory of Spitzer [1943] for the wave propagation in gassy water by adapting that for a viscoelastic, lossy medium, though without providing a detailed derivation. Following Leighton [2007], this paper presents a theory based on non-stationary nonlinear dynamics of spherical gas bubbles and extends that 2007 paper to include liquid compressibility and thermal damping effects. The paper then shows how that nonlinear formulation can be reduced to the linear limit, and from this it derives the expressions for the damping coefficients, the scattering cross section, the speed of sound and the attenuation, and compares these with the A&H theory. The current formulation has certain advantages over A&H theory such as implementing an energy conservation based, nonlinear model for the gas pressure inside the bubble, having no sign ambiguity for the speed of sound formula (which is important when estimating the bubble void fraction in marine sediments) and correcting the ambiguity on the expression for scattering cross section, as identified in the recent work of Ainslie and Leighton [2011].

More than three decades ago, Anderson and Hampton [1, 2] (A&H) presented theories for wave propagation in gassy water, saturated sediments and gassy sediments in their two part review, which has been cited by many researchers in the geoacoustics and underwater acoustics areas. They gave an empirical formulation based on the theory of Spitzer [3] for the wave propagation in gassy water by adapting that for a viscoelastic, lossy medium. Following Leighton [4], this paper presents a theory based on non-stationary nonlinear dynamics of spherical gas bubbles and extends that 2007 paper to include liquid compressibility and thermal damping effects. The paper then shows how that nonlinear formulation can be reduced to the linear limit, and derives the expressions for the damping coefficients, the scattering cross section, the speed of sound and the attenuation, and compares these with the A&H theory. The current formulation has certain advantages over A&H theory such as implementing an energy conservation based nonlinear model for the gas pressure inside the bubble, having no sign ambiguity for the speed of sound formula (which is important when estimating the bubble void fraction) and correcting the ambiguity on the expression for scattering cross section, as identified in the recent work of Ainslie and Leighton [5]. Moreover, the theory presented here forms a basis for a nonlinear, time-dependent acoustic estimation model for gas bubble distributions in viscoelastic mediums since it avoids the commonly encountered assumptions on the bubble dynamics such as linearity, steady-state behaviour and monochromaticity.

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconfiguration example results and performance. QC 20121114

The current conservation status of the Salvia L. (sage) taxa of the family Lamiaceae distributed in the East, South-East, Central, North Anatolian, and Marmara geographic regions of Turkey was reassessed at regional, national, and global levels using IUCN Red List categories and criteria. In accordance with the present taxonomic revision of the genus since 2005, the study area seems to cover 79 taxa, 36 of which are endemic and 4 of which are rare nonendemic; the remaining 39 taxa are widely distributed. The rate of endemism is 46% in the area. Based on new field observations of populations and distribution data, taxa were classified into the following threat categories at the global scale: Critically Endangered (CR) (5 taxa), Endangered (EN) (8 taxa), Vulnerable (VU) (11 taxa), Near Threatened (NT) (12 taxa), and Least Concern (LC) (43 taxa). The most threatened species at the global scale are S. anatolica, S. ballsiana, S. freyniana, S. odontochlamys, and S. pseudeuphratica. The threatened taxa are under pressure from intensive human activities such as overgrazing, construction (e.g., road construction), land clearing (e.g., agricultural activities), and urbanisation. The threatened endemic taxa are concentrated in 3 main areas. The first area includes Sivas, Divrigi, Gurun, Pinarbasi, and Kemaliye. The second area includes Ankara, Beypazari, Polatli, and Sivrihisar. The third area includes Yozgat, Akdagmadeni, Nevsehir, and Kayseri. Some significant measures are recommended here for the conservation and management of the high number of endemic taxa under threat in the research area.