46 research outputs found
Average Probability of Bit Error of MPSK in Combined Flat Ionospheric Scintillation and Flat Fading Channels
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A Lightweight Treatment of Inexact Dates
No full textThis paper presents a lightweight approach to representing inexact dates on the semantic web, in that it imposes minimal ontological commitments on the ontology author and provides data that can be queried using standard approaches. The approach is presented in the context of a significant need to represent inexact dates but the heavyweight nature of existing proposals which can handle such information. Approaches to querying the represented information and an example user interface for creating such information are presented
Low-latitude equinoctial spread-F occurrence at different longitude sectors under low solar activity
No full textWe present the results of a comparative study of spread-F signatures over five low-latitude sites: Chiangmai (CGM; 18.8° N, 98.9° E, mag. Lat. 8.8° N), Thailand; Tanjungsari (TNJ; 6.9° S, 107.6° E, mag. Lat. 16.9° S), Indonesia; Palmas (PAL; 10.2° S, 311.8° E, mag. Lat. 0.9° S) and São José Dos Campos (SJC; 23.2° S, 314.1° E, mag. Lat. 14.0° S), Brazil; and Tucumán (TUC; 26.9° S, 294.6° E, mag. Lat. 16.8° S), Argentina. The investigation was based on simultaneous ionograms recorded by an FMCW (frequency-modulated continuous-wave) at CGM, an IPS-71 (digital ionosonde from KEL aerospace) at TNJ, a CADI (Canadian Advanced Digital Ionosonde) at PAL and SJC, and an AIS-INGV (Advanced Ionospheric Sounder – Istituto Nazionale di Geofisica e Vulcanologia) at TUC, during the equinoctial periods March–April (R12 = 2.0 and R12 = 2.2) and September–October (R12 = 6.1 and R12 = 7.0) 2009, for very low solar activity. Spread-F signatures were categorized into two types: the range spread-F (RSF) and the frequency spread-F (FSF). The study confirms that the dynamics and the physical processes responsible for these phenomena are actually complicated. In fact, the features that arise from the investigation are different, depending on both the longitude sector and on the hemisphere. For instance, TUC, under the southern crest of the ionospheric equatorial ionization anomaly (EIA), shows a predominance of RSF signatures, while both SJC, under the southern crest of EIA but in a different longitude sector, and CGM, under the northern crest of EIA, show a predominance of FSF signatures. Moreover, the spread-F occurrence over the longitude sector that includes CGM and TNJ is significantly lower than the spread-F occurrence over the longitude sector of PAL, SJC, and TUC.Fil: Pezzopane, M.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Zuccheretti, E.. Istituto Nazionale Di Geofisica E Vulcanologia; Italia;Fil: Abadi, P.. Indonesian National Institute of Aeronautics and Space. Space Science Center. Division of Ionosphere and Telecommunication; Indonesia;Fil: de Abreu, A. J.. Universidade do Vale do Paraíba; Brazil;Fil: de Jesus, R.. Universidade do Vale do Paraíba; Brazil;Fil: Fagundes, P. R.. Universidade do Vale do Paraíba; Brazil;Fil: Supnithi, P.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Rungraengwajiake, S.. King Mongkut’s Institute of Technology Ladkrabang . Faculty of Engineering; Tailandia;Fil: Nagatsuma, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Tsugawa, T.. National Institute of Information and Communications Technology. Space Weather and Environment Informatics Laboratory; Japón;Fil: Cabrera, Miguel Angel. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Electricidad, Electrónica y Computación. Laboratorio de Telecomunicaciones; Argentina; Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina;Fil: Ezquer, Rodolfo Gerardo. Universidad Tecnológica Nacional. Facultad Regional Tucumán. Centro de Investigación de Atmósfera Superior y Radiopropagación; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina; Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionosfera; Argentina
The Development of an Audible Pattani Malay-Thai Electronic Phrasebook for Military Purposes
No full textAbstractPattani Malay is a minority language spoken by ethnic Malays in southernmost provinces of Thailand, and it plays a strategically and politically crucial role in municipal governance in the area. This paper presents the development of a multimodal Pattani Malay-Thai corpus and its application to an audible electronic phrasebook for military purposes. The bilingual corpus contains 10,000 parallel sentences and sound recordings in both languages. A mobile application based on Android platform is developed on top of the corpus and offers the search engine for on-field usage and reconnoiters, as well as language lessons for military personnels
A study of multiple reads of target track prior to detection for two-dimensional magnetic recording
No full textUnequal error correction strategy for magnetic recording systems with multi-track processing
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