Adaptive wireless multimedia communication systems

In recent years, due to the rapid convergence of multimedia services, Internet and wireless communications, there has been a growing trend of heterogeneity (in terms of channel bandwidths, mobility levels of terminals, end-user quality-of-service (QoS) requirements) for emerging integrated wired/wireless networks. Moreover, in nowadays systems, a multitude of users coexists within the same network, each of them with his own QoS requirement and bandwidth availability. In this framework, embedded source coding allowing partial decoding at various resolution is an appealing technique for multimedia transmissions. This dissertation includes my PhD research, mainly devoted to the study of embedded multimedia bitstreams in heterogenous networks, developed at the University of Bologna, advised by Prof. O. Andrisano and Prof. A. Conti, and at the University of California, San Diego (UCSD), where I spent eighteen months as a visiting scholar, advised by Prof. L. B. Milstein and Prof. P. C. Cosman. In order to improve the multimedia transmission quality over wireless channels, joint source and channel coding optimization is investigated in a 2D time-frequency resource block for an OFDM system. We show that knowing the order of diversity in time and/or frequency domain can assist image (video) coding in selecting optimal channel code rates (source and channel code rates). Then, adaptive modulation techniques, aimed at maximizing the spectral efficiency, are investigated as another possible solution for improving multimedia transmissions. For both slow and fast adaptive modulations, the effects of imperfect channel estimation errors are evaluated, showing that the fast technique, optimal in ideal systems, might be outperformed by the slow adaptive modulation, when a real test case is considered. Finally, the effects of co-channel interference and approximated bit error probability (BEP) are evaluated in adaptive modulation techniques, providing new decision regions concepts, and showing how the widely used BEP approximations lead to a substantial loss in the overall performance.

Research on the vocal culture of Orcinus orca in the Loro Parque, Tenerife: a pilot study

This research is focussed on the study of Orcinus orca's communication system. The analysis of vocalizations emitted by marine mammals has started in the '80s and most studies have been carried out in the wild. In this regard the most studied animal has been common dolphin (Tursiops truncatus) as the numerous presence of captive individuals worldwide made researches easier to be carried out. Studies about Orcinus orca's vocalizations have mainly been carried out in the wild (most in British Columbia) because its maintenance in a controlled environment results to be very difficult, only 17 among parks and oceanaria worldwide have some Orcinus orca (45 overall among which 64% born in captivity). These researches showed that Orcinus orca emit three main different types of sounds, classified as: whistles, clicks and calls. Besides, it was discovered that different groups (pods) produce sounds belonging only to the relevant pod (dialects). It is rare to find two pods sharing some calls. The two pods usually live in adjacent areas and can form a clan. This study was carried out in a controlled environment in the Orca ocean structure (Loro Parque, Tenerife, Spain) where, at the moment (March 2012) 6 individuals are hosted. Here it was developed an automatic sound recording system. Thanks to the use of suitable mathematical algorithms that allow to isolate only "interesting" sound events that differ from the "background noise", it was possible to create a database. The visualization of the sound events collected in the database is carried out with the use of a software. By looking at this output and at the observation register we could match the animal to the sound produced. Three situations were detected and studied: 1) Chosen alone: the animal chooses to go to the recording pool but it is free to move to another pool with other individuals. 2) Put alone: the animal is put alone in the recording pool. 3) With other orcas: more animals are together in the recording pool. The statistic analysis show that animals emit more vocalizations when they are in the situation "Chosen alone". The research will continue in order to observe eventual differences in the individual repertoire of each Orcinus orca.

Enabling Techniques and Algorithms for Integrated Communication and Navigation Satellite Systems

This thesis presents the outcomes of my Ph.D. course in telecommunications engineering. The focus of my research has been on Global Navigation Satellite Systems (GNSS) and in particular on the design of aiding schemes operating both at position and physical level and the evaluation of their feasibility and advantages. Assistance techniques at the position level are considered to enhance receiver availability in challenging scenarios where satellite visibility is limited. Novel positioning techniques relying on peer-to-peer interaction and exchange of information are thus introduced. More specifically two different techniques are proposed: the Pseudorange Sharing Algorithm (PSA), based on the exchange of GNSS data, that allows to obtain coarse positioning where the user has scarce satellite visibility, and the Hybrid approach, which also permits to improve the accuracy of the positioning solution. At the physical level, aiding schemes are investigated to improve the receiver’s ability to synchronize with satellite signals. An innovative code acquisition strategy for dual-band receivers, the Cross-Band Aiding (CBA) technique, is introduced to speed-up initial synchronization by exploiting the exchange of time references between the two bands. In addition vector configurations for code tracking are analyzed and their feedback generation process thoroughly investigated.

An Input-Process-Output Approach to Interorganizational Teams: The Influence of Work Group Diversity, Trust and Shared Leadership on Communication Network and Team Outputs.

The market’s challenges bring firms to collaborate with other organizations in order to create Joint Ventures, Alliances and Consortia that are defined as “Interorganizational Networks” (IONs) (Provan, Fish and Sydow; 2007). Some of these IONs are managed through a shared partecipant governance (Provan and Kenis, 2008): a team composed by entrepreneurs and/or directors of each firm of an ION. The research is focused on these kind of management teams and it is based on an input-process-output model: some input variables (work group’s diversity, intra-team's friendship network density) have a direct influence on the process (team identification, shared leadership, interorganizational trust, team trust and intra-team's communication network density), which influence some team outputs, individual innovation behaviors and team effectiveness (team performance, work group satisfaction and ION affective commitment). Data was collected on a sample of 101 entrepreneurs grouped in 28 ION’s government teams and the research hypotheses are tested trough the path analysis and the multilevel models. As expected trust in team and shared leadership are positively and directly related to team effectiveness while team identification and interorganizational trust are indirectly related to the team outputs. The friendship network density among the team’s members has got positive effects on the trust in team and on the communication network density, and also, through the communication network density it improves the level of the teammates ION affective commitment. The shared leadership and its effects on the team effectiveness are fostered from higher level of team identification and weakened from higher level of work group diversity, specifically gender diversity. Finally, the communication network density and shared leadership at the individual level are related to the frequency of individual innovative behaviors. The dissertation’s results give a wider and more precise indication about the management of interfirm network through “shared” form of governance.

Brain-Computer Interfaces for augmented communication: Asynchronous and adaptive algorithms and evaluation with end users

This thesis aimed at addressing some of the issues that, at the state of the art, avoid the P300-based brain computer interface (BCI) systems to move from research laboratories to end users’ home. An innovative asynchronous classifier has been defined and validated. It relies on the introduction of a set of thresholds in the classifier, and such thresholds have been assessed considering the distributions of score values relating to target, non-target stimuli and epochs of voluntary no-control. With the asynchronous classifier, a P300-based BCI system can adapt its speed to the current state of the user and can automatically suspend the control when the user diverts his attention from the stimulation interface. Since EEG signals are non-stationary and show inherent variability, in order to make long-term use of BCI possible, it is important to track changes in ongoing EEG activity and to adapt BCI model parameters accordingly. To this aim, the asynchronous classifier has been subsequently improved by introducing a self-calibration algorithm for the continuous and unsupervised recalibration of the subjective control parameters. Finally an index for the online monitoring of the EEG quality has been defined and validated in order to detect potential problems and system failures. This thesis ends with the description of a translational work involving end users (people with amyotrophic lateral sclerosis-ALS). Focusing on the concepts of the user centered design approach, the phases relating to the design, the development and the validation of an innovative assistive device have been described. The proposed assistive technology (AT) has been specifically designed to meet the needs of people with ALS during the different phases of the disease (i.e. the degree of motor abilities impairment). Indeed, the AT can be accessed with several input devices either conventional (mouse, touchscreen) or alterative (switches, headtracker) up to a P300-based BCI.

A model for radiofrequency electromagnetic field predictions at outdoor and indoor locations in the context of epidemiological research

We present a geospatial model to predict the radiofrequency electromagnetic field from fixed site transmitters for use in epidemiological exposure assessment. The proposed model extends an existing model toward the prediction of indoor exposure, that is, at the homes of potential study participants. The model is based on accurate operation parameters of all stationary transmitters of mobile communication base stations, and radio broadcast and television transmitters for an extended urban and suburban region in the Basel area (Switzerland). The model was evaluated by calculating Spearman rank correlations and weighted Cohen's kappa (kappa) statistics between the model predictions and measurements obtained at street level, in the homes of volunteers, and in front of the windows of these homes. The correlation coefficients of the numerical predictions with street level measurements were 0.64, with indoor measurements 0.66, and with window measurements 0.67. The kappa coefficients were 0.48 (95%-confidence interval: 0.35-0.61) for street level measurements, 0.44 (95%-CI: 0.32-0.57) for indoor measurements, and 0.53 (95%-CI: 0.42-0.65) for window measurements. Although the modeling of shielding effects by walls and roofs requires considerable simplifications of a complex environment, we found a comparable accuracy of the model for indoor and outdoor points.

Communication skills training in oncology: a position paper based on a consensus meeting among European experts in 2009

Background: Communication in cancer care has become a major topic of interest. Since there is evidence that ineffective communication affects both patients and oncology clinicians (physicians and nurses), so-called communication skills trainings (CSTs) have been developed over the last decade. While these trainings have been demonstrated to be effective, there is an important heterogeneity with regard to implementation and with regard to evidence of different aspects of CST. Methods: In order to review and discuss the scientific literature on CST in oncology and to formulate recommendations, the Swiss Cancer League has organised a consensus meeting with European opinion leaders and experts in the field of CST, as well as oncology clinicians, representatives of oncology societies and patient organisations. On the basis of a systematic review and a meta-analysis, recommendations have been developed and agreed upon. Results: Recommendations address (i) the setting, objectives and participants of CST, (ii) its content and pedagogic tools, (iii) organisational aspects, (iv) outcome and (v) future directions and research. Conclusion: This consensus meeting, on the basis of European expert opinions and a systematic review and meta-analysis, defines key elements for the current provision and future development and evaluation of CST in oncology.

Making Research Relevant to Development - Experience from the NCCR North-South

Making research relevant to development is a complex, non-linear and often unpredictable process which requires very particular skills and strategies on the part of researchers. The National Centre of Competence in Research (NCCR) North-South provides financial and technical support for researchers so that they can effectively cooperate with policy-makers and practitioners. An analysis of 10 years of experience translating research into development practise in the NCCR North-South revealed the following four strategies as particularly relevant: a) research orientation towards the needs and interests of partners; b) implementation of promising methods and approaches; c) communication and dissemination of research results; and d) careful analysis of the political context through monitoring and learning approaches. The NCCR North-South experience shows that “doing excellent research” is just one piece of the mosaic. It is equally important to join hands with non-academic partners from the very beginning of a research project, in order to develop and test new pathways for sustainable development. Capacity building – in the North and South – enables researchers to do both: To do excellent research and to make it relevant for development.

The Mountain Research Initiative Reaches Outward and Clombs Upward

Mountain regions provide a multitude of goods and services for much of humanity (Price and Butt 2000; Becker and Bugmann 2001), especially in the realms of water supply, biodiversity, and other ecosystem services (Schimel et al 2002; Körner et al 2005; Viviroli et al 2007; Viviroli et al 2011). However, the future ability of mountain regions to provide goods and services to both highland and lowland residents is seriously threatened by climatic changes, environmental pollution, unsustainable management of natural resources, and serious gaps in understanding of mountain systems (Huber et al 2005). Disciplinary, interdisciplinary, and transdisciplinary research is required to maintain these goods and services in the face of these forces. The global mountain research community, however, has historically operated at a suboptimal level because of insufficient communication across geographic and linguistic barriers, less than desirable coordination of research frameworks, and a lack of funding.

Communication in troubled waters: responses of fish communication systems to changing environments

Fish populations are increasingly being subjected to anthropogenic changes to their sensory environments. The impact of these changes on inter- and intra-specific communication, and its evolutionary consequences, has only recently started to receive research attention. A disruption of the sensory environment is likely to impact communication, especially with respect to reproductive interactions that help to maintain species boundaries. Aquatic ecosystems around the world are being threatened by a variety of environmental stressors, causing dramatic losses of biodiversity and bringing urgency to the need to understand how fish respond to rapid environmental changes. Here, we discuss current research on different communication systems (visual, chemical, acoustic, electric) and explore the state of our knowledge of how complex systems respond to environmental stressors using fish as a model. By far the bulk of our understanding comes from research on visual communication in the context of mate selection and competition for mates, while work on other communication systems is accumulating. In particular, it is increasingly acknowledged that environmental effects on one mode of communication may trigger compensation through other modalities. The strength and direction of selection on communication traits may vary if such compensation occurs. However, we find a dearth of studies that have taken a multimodal approach to investigating the evolutionary impact of environmental change on communication in fish. Future research should focus on the interaction between different modes of communication, especially under changing environmental conditions. Further, we see an urgent need for a better understanding of the evolutionary consequences of changes in communication systems on fish diversity.

Coping With a Family Member's Death: Parenting, Religiosity, and Parent-Child Communication

The present study had three major aims. First, this study was a basic descriptive exploration of the frequency and nature of parent-child communication about death. Second, this study conducted a quantitative analysis to identify predictors of communication and bereaved children¿s emotional and behavioral problems. Third, this study was also a qualitative analysis of parents¿ descriptions of how religious views shape conversations about death and how conversations are beneficial. Based on prior research, it was predicted that positive child outcomes would be associated with parental warmth, religiosity, adaptive coping, positive religious coping, and frequent parent-child communication about death. Conversely, it was predicted that negative child outcomes would be associated with parental psychological control, maladaptive coping, negative religious coping, and less frequent parent-child communication about death. Additionally, it was hypothesized that parents¿ religious and spiritual views would shape parent-child communication about death, and parents would describe numerous benefits of discussing death with children. Parents completed a series of survey measures assessing their religiosity, coping strategies, parent-child communication about death, and their children¿s emotional and behavioral symptoms. Almost 80% of parent-child dyads discussed death at least once a week, and children initiated approximately half of these conversations. Parent-child communication about death was predicted by parents¿ warmth toward and acceptance of their children and inversely predicted by children¿s hyperactivity and social problem solving. Higher levels of children¿s social problem solving could predict lower frequency of parent-child communication about death if children were holding frequent, meaningful, and comforting conversations with friends and other adults. Higher levels of parents¿ psychological control predicted more emotional and behavioral problems in the child. Parents¿ adaptive coping had significant relationships with all of the dimensions of parent-child communication about death. Qualitative analyses revealed that parents perceived their religious beliefs as shaping conversations about death and grief as an individualized journey. A majority of parents described the emotional, social, and intellectual benefits of holding parent-child conversations about death. This study contributes to the literature by further describing parent-child communication about death, identifying its predictors, and investigating parents¿ religiosity and coping strategies in relation to child well-being. Overall, this study revealed the importance of assessing global parenting characteristics (i.e., warmth/acceptance and psychological control) when examining parent-child relationships and communication about death. Furthermore, this unique study illustrates the value of qualitative data when examining parent-child communication about death and religiosity.

Quality of analgesic treatment in patients with advanced prostate cancer: do we do a better job now? The Swiss Group for Clinical Cancer Research (SAKK) experience

GOALS OF WORK: The aim of this study was to evaluate pain intensity and the application of the WHO guidelines for cancer pain treatment in patients with prostate cancer treated at Swiss cancer centers. MATERIALS AND METHODS: We analyzed a series of five multicenter phase II clinical trials which examined the palliative effect of different chemotherapies in patients with advanced hormone-refractory prostate carcinoma. Of 170 patients, 1,018 visits were evaluable for our purpose, including ratings of pain intensity by patients and prescribed analgesics. MAIN RESULTS: No or mild pain was indicated by patients in 36 to 55% of the visits, more than mild pain in 30 to 46%. In 21% of the visits, the WHO pain treatment criteria (treatment according to one of the three steps; oral, rectal or transdermal application of the main dose; administration on a regular schedule) were fulfilled, and the Cleeland index was positive according to all recommendations. In 6% of the visits, neither the WHO criteria were fulfilled nor was the Cleeland index positive. This indicates insufficient pain treatment not following the WHO guidelines and that the prescribed analgesics were not sufficiently potent for the rated pain intensity. CONCLUSIONS: In this selective Swiss sample, the standard of analgesic treatment is high. However, there is still scope for improvement. This cannot solely be solved by improving the knowledge of the physicians. Programs to change the patients' attitude towards cancer pain, training to improve the physicians' communication skills, and institutional changes may be promising strategies.