Considering Bluetooth's Subband Codec (SBC) for Wideband Speech and Audio on the Internet

The Bluetooth Special Interest Group (SIG) has standardized the subband coding (SBC) audio codec to connect headphones via wireless Bluetooth links. SBC compresses audio at high fidelity while having an ultra-low algorithm delay. To make SBC suitable for the Internet, we extend it by using a time and packet loss concealment (PLC) algorithm that is based on ITU's G.711 Appendix I. The design is novel in the aspect of the interface between codec and speech receiver. We developed a new approach on how to distribute the functionality of a speech receiver between codec and application. Our approach leads to easier implementations of high quality VoIP applications. We conducted subjective and objective listening tests of the audio quality of SBC and PLC in order to determine an optimal coding mode and the trade-off between coding mode and packet loss rate. More precisely, we conducted MUSHRA listening tests for selected sample items. These tests results are then compared with the results of multiple objective assessment algorithms (ITU P.862 PESQ, ITU BS.1387-1 PEAQ, Creusere's algorithm). We found out that a combination of the PEAQ basic and advanced values best matches---after third order linear regression---the subjective MUSHRA results . The linear regression has coefficient of determination of R²=0.907². By comparison, our individual human ratings show a correlation of about R=0.9 compared to our averaged human rating results. Using the combination of both PEAQ algorithms, we calculate hundred thousands of objective audio quality ratings varying audio content and algorithmic parameters of SBC and PLC. The results show which set of parameters value are best suitable for a bandwidth and delay constrained link. The transmission quality of SBC is enhanced significantly by selecting optimal encoding parameters as compared to the default parameter sets given in the standard. Finally, we present preliminary objective tests results on the comparison of the audio codecs SBC, CELT, APT-X and ULD coding speech and audio transmission. They all allow a mono and stereo transmission of music at ultra-low coding delays (<10ms), which is especially useful for distributed ensemble performances over the Internet

Modeling user’s trust in M-commerce acceptance: A conceptual framework in context of Pakistan

With the emergence of Intern ate and world wide web traditional business got new opportunity to complete globally. Traditional bricks-and-mortar business became electronic business ( e-business) by utilizing information and communication technology (ICT) tools. A new term of Mobile Commerce (M-Commerce) has created tremendous spectrum of business opportunities for businesses. Although there has been large scale adoption of M-Commerce in developing economies, but little growth is observed in developing economies such as Pakistan. There are doubts that users of M-Commerce demonstrate a lack of enthusiasm, which may be due to lack of trustworthiness. Based on the well-known and widely used technology acceptance model (TAM), this research study provides the conceptual framework, underpinning the relationship of trust with adoption of M-Commerce in Pakistan. The aim of this paper is to study the role of trust and its relationship with the acceptance of M-Commerce in Pakistan

Cooperative Communications: A New Trend in the Wireless World

Abstract—This Wireless channel while offering independence of movement also introduces un-reliability in the messages received at the destination. Various strategies have been introduced so far to mitigate the effects of the channel on the message received. In this paper, we give an introductory overview of cooperative communications, a new trend in this field of wireless Communications where the transmitting users help each other to overcome the Effects of wireless channel on the message received at the destination. We compare the new idea of cooperative communications with traditional direct or noncooperative communications. In particular, we discuss the achievable rates and simulate the system to get the probability of outage performance of cooperative communications and compare it with direct or noncooperative communications

A survey of searching and information extraction on a classical text using ontology-based semantics modeling: a case of Quran

Quran is the religious text of Islam. Followers of Islam believe that it is the verbatim word of Allah (God). In the last few years, the Quran has become a target of interest for researchers in the field of computer science, for exploring the divine knowledge encapsulated in it. Since the last few years ontologies have gained significant importance in computer science research because of its machine understandable and semantic nature. Ontologies play an important role in supporting the notion of the semantic web. Some work has been done on the Quran exploiting the platform of ontologies. This paper presents a survey based on recent works which uses ontologies as a means of representing and encapsulating the knowledge of the Quran. In order to compare the reviewed literature, an authentic framework is used which is applicable to any ontology application. Furthermore, the paper includes a comprehensive comparison table based on the framework which allows the readers to understand the details of all works in a glance. At the end of the paper, the conclusion and future work section highlights the shortcomings of the existing works and give a sense of direction to aspiring researchers in order to contribute to the domain of the Quran

The Saudi National Mental Health Survey: Survey instrument and field procedures

ObjectivesTo present an overview of the survey and field procedures developed for the Saudi National Mental Health Survey (SNMHS).MethodsThe SNMHS is a face- to- face community epidemiological survey of DSM- IV mental disorders in a nationally representative sample of the household population in the Kingdom of Saudi Arabia (KSA) (n = 4,004). The SNMHS was implemented as part of the WHO World Mental Health (WMH) Survey Initiative. WMH carries out coordinated psychiatric epidemiological surveys in countries throughout the world using standardized procedures designed to provide valid cross- national comparative data on prevalence and correlates of common mental disorders. However, these procedures need to be adapted to the unique experiences in each country. We focus here on the adaptations made for the SNMHS.ResultsModifications were needed to several interview sections and expansions were needed to address issues of special policy importance in KSA. Several special field implementation challenges also had to be addressed because of the need for female interviewers to travel with male escorts and for respondents to be interviewed by interviewers of the same gender.ConclusionsThoughtful revisions led to a high- quality field implementation in the SNMHS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162792/2/mpr1830.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162792/1/mpr1830_am.pd

Implications of risk conferred by 5p15.33 loci genetic variants; human telomerase reverse transcriptase rs2736098 and rs2736100 in predisposition of bladder cancer

Background: The polymorphic variations of human telomerase reverse transcriptase (hTERT) gene play an important role in predisposition to carcinogenesis. The current study aimed to elucidate the genetic predisposition to bladder cancer in two important variants, rs2736098 and rs2736100 of hTERT gene. Materials and methods: Confirmed 130 patients of bladder cancer and 200 healthy controls were genotyped by PCR-RFLP to determine different variants of hTERT rs2736098 and rs2736100. Results: hTERT rs2736098 homozygous variant AA genotype frequency was observed to significantly differ 2-fold between cases and controls (26.15% vs. 13.5%) (p = 0.02). In addition, rare ‘A’ allele significantly differed among two groups (cases: 47% versus controls: 39%: p = 0.03). hTERT rs2736098 was observed to be presented significantly more in high stage tumors (p = 0.02). hTERT rs2736100 genotype AA or variant allele A showed no significant difference between cases and controls. Haplotype CA displayed significantly different pattern of frequency as 0.5 in cases as compared to 0.16 in controls (p &lt; 0.0001). Combination of variant A/G haplotype frequency implicated more in cases than in controls (0.34 vs. 0.16, p = 0.001). Conclusions: It is concluded that hTERT rs2736098 polymorphic variant has a vital role to confer a strong risk to bladder cancer in our population. Further, hTERT haplotypes CA and AG inhTERT could prove to be a promising tool to screen the risk for bladder cancer

Optimierung von Spatial Audio Telefonie und Telekonferenz

The invention of telephony has brought a significant revolution to our lives and is undoubtedly considered one of the most important inventions of the modern-day world. But over the last decades hardly any improvements in audio quality have been achieved. Telephony still suffers from issues such as low speech intelligibility, poor audio quality and extraneous noise. To improve the quality of telephony the use of spatial (or 3D) audio has been proposed. 3D audio can offer significant advantages, such as enhanced overall audio and speech quality, since our natural listening ability is inherently three dimensional. Here, the nature of Virtual Acoustic Environments (VAE), which are used in most of the 3D audio simulations, play a very important rule in the perception of spatial audio. Due to the importance of VAEs, there is need for studying various VAE parameters to properly design virtual acoustic rooms for the benefit of better audio quality, speech intelligibility and enhanced localization performance. This thesis introduces a telephony and teleconferencing system supporting three dimensional audio and customizable virtual acoustic environments. The system consists of a VoIP based telephone extended by low-delay audio codecs, three dimensional renderers, and head phones extended by head-tracking sensors. This thesis also presents a series of experiments conducted to optimize the 3D telephony system. In the experimental study various parameters are considered to validate speech quality, locatability and speech intelligibility of the teleconferencing participants. Within two different VAEs, seven different placement of participants were studied. In addition, eleven sets of user experiments are described in this thesis that examine the effects of simulated acoustic room properties, virtual sitting arrangements, reflections of a conference table, number of concurrent talkers and voice characteristics. This thesis also presents three interlocutor based live conversational tests to compare the audio qualities of mono, stereo and spatial conversations with and without head-tracking. A conceptual and holistic Quality of Experience (QoE) model comprising all domains of a communication ecosystem and the relationships between QoE and virtual acoustic environments is also presented. The model is evaluated through user studies and empirical analysis. Based on this model, a use case study is presented for three dimensional telephony. Also the interaction and classification of QoE factors and contextual aspects are presented.Die Erfindung des Telefons übt einen signifikanten Einfluss auf das moderne Leben aus und kann zweifelsohne als eine der wichtigsten Erfindungen der Moderne angesehen werden. Doch während der letzten Jahrzehnte hat sich die sprachliche Qualität dieser Erfindung kaum gebessert. So leiden Nutzer des Telefons noch immer an Problemen wie Verständnisschwierigkeiten, mangelhafter Audioqualität und Störgeräuschen. Um diese Probleme zu beheben wurde der Einsatz von Raumklang (3D-Audio) vorgeschlagen. 3D Audio bietet erhebliche Vorteile für die Audio- und Sprachqualität, da der Mensch von Natur aus räumlich hört. Die Beschaffenheit der Virtuellen Akustischen Umgebung (VAU) übt dabei einen großen Einfluss auf die Wahrnehmung des Raumklanges aus. Aus diesem Grund ist es notwendig, unterschiedliche Parameter einer VAU auf ihren Einfluss auf die Sprachverständlichkeit, Audioqualität und Lokalisierbarkeit zu untersuchen. Diese Arbeit stellt daher ein Telefon- und Telekonferenzsystem vor, das 3D Audiotechnologien und individuell konfigurierbare VAUs unterstützt. Das System besteht aus einem VoIP-Softphone, das um Codecs mit geringer Verzögerung erweitert wurde, 3D Renderern und Kopfhörern mit Head-Tracking Sensoren. Weiterhin beschreibt diese Arbeit eine Reihe experimenteller Messungen zur Optimierung des Telefonsystems. Die Experimente umfassen die Evaluierung unterschiedlicher Parameter zur Beschreibung der Sprachqualität, Sprachverständlichkeit und Lokalisierbarkeit der Teilnehmer einer Telekonferenz. So wurden sieben unterschiedliche Teilnehmerplatzierungen in zwei unterschiedlichen VAUs evaluiert. In elf weiteren Szenarien wurde der Einfluss unterschiedlicher Umgebungsparameter, Teilnehmerplatzierungen, eines Konferenztisches sowie der Anzahl simultaner Sprecher und deren Stimmcharakteristika untersucht. Zusätzlich wurden Konversationstests durchgeführt, die den Einfluss von Mono-, Stereo- und Raumklang sowie den Einsatz von Head-Tracking-Kopfhörern auf die Audioqualität messen. Letztendlich beschreibt diese Arbeit ein konzeptuelles, ganzheitliches Quality of Experience (QoE)-Modell, das alle Domänen eines Kommunikations-Ökosystems sowie die Beziehungen zwischen QoE-Aspekten und VAUs umfasst. Eine Auswertung des Modells anhand von Nutzerstudien und empirischer Analyse wird dargestellt. Auf der Basis dieses Modells wird außerdem eine Fallstudie mit dem Schwerpunkt 3D Telefonie beschrieben, und eine Klassifikation von QoE-Faktoren und deren Interaktionen mit kontextuellen Aspekten präsentiert

Measuring 3D Audio Localization Performance and Speech Quality of Conferencing Calls for a Multiparty Communication System

Communication systems which support 3D (Three Dimensional) audio offer a couple of advantages to the users/customers. Firstly, within the virtual acoustic environments all participants could easily be recognized through their placement/sitting positions. Secondly, all participants can turn their focus on any particular talker when multiple participants start talking at the same time by taking advantage of the natural listening tendency which is called the Cocktail Party Effect. On the other hand, 3D audio is known as a decreasing factor for overall speech quality because of the commencement of reverberations and echoes within the listening environment. In this article, we study the tradeoff between speech quality and human natural ability of localizing audio events/or talkers within our three dimensional audio supported telephony and teleconferencing solution. Further, we performed subjective user studies by incorporating two different HRTFs (Head Related Transfer Functions), different placements of the teleconferencing participants and different layouts of the virtual environments. Moreover, subjective user studies results for audio event localization and subjective speech quality are presented in this article. This subjective user study would help the research community to optimize the existing 3D audio systems and to design new 3D audio supported teleconferencing solutions based on the quality of experience requirements of the users/customers for agriculture personal in particular and for all potential users in general