Trust-based mechanisms for secure communication in cognitive radio networks

Cognitive radio (CR) technology was introduced to solve the problem of spectrum scarcity to support the growth of wireless communication. However, the inherent properties of CR technology make such networks more vulnerable to attacks. This thesis is an effort to develop a trust-based framework to ensure secure communication in CRN by authenticating trustworthy nodes to share spectrum securely and increasing system's availability and reliability by selecting the trustworthy key nodes in CRNs

The Cost of Convenience: How Excessive Email Use Impacts Our Health

Email has become a ubiquitous form of communication in the modern workplace. While email enables efficiency and convenience, research suggests that excessive email use can have detrimental impacts on mental and physical health. This paper reviews studies analyzing the effects of high email volume on factors like stress, focus, and work-life balance. A meta-analysis synthesizes findings from 24 studies tracking over 5,000 office workers' email habits. Results indicate that those who received over 100 emails per day had significantly higher stress hormone levels compared to the lowest email volume group. Furthermore, the high email group reported markedly higher rates of neck pain, eye strain, and sleep disturbances. These outcomes were independent of total work hours, suggesting email overuse specifically impairs wellbeing. Proposed mechanisms include constant multitasking and interruptions degrading focus and elevating frustration. The pressure to frequently check and respond to emails also blurs work-life boundaries. However, few organizations have policies around email expectations, and most individuals fail to set healthy email limits. Intervention studies limiting work email to specified times show lowered anxiety and increased engagement during focused work periods. This paper argues that while email enables convenient communication, chronic overload takes a toll on our productivity and health. Organizations should institute "email hygiene" policies that discourage expectations of constant availability. Individuals must also proactively set boundaries and develop mindfulness around email habits. Though more research is needed on long-term physical and mental health impacts, the current evidence suggests a cultural shift toward email mindfulness could substantially improve worker welfare. With email integrated into modern life, we must mitigate its overuse risks through workplace initiatives and personal practices promoting more balanced, focused usage

Reasoning about ideal interruptible moments: A soft computing implementation of an interruption classifier in free-form task environments

Current trends in society and technology make the concept of interruption a central human computer interaction problem. In this work, a novel soft computing implementation for an Interruption Classifier was designed, developed and evaluated that draws from a user model and real-time observations of the user\u27s actions as s/he works on computer-based tasks to determine ideal times to interact with the user. This research is timely as the number of interruptions people experience daily has grown considerably over the last decade. Thus, systems are needed to manage interruptions by reasoning about ideal timings of interactions. This research shows: (1) the classifier incorporates a user model in its’ reasoning process. Most of the research in this area has focused on task-based contextual information when designing systems that reason about interruptions; (2) the classifier performed at 96% accuracy in experimental test scenarios and significantly out-performed other comparable systems; (3) the classifier is implemented using an advanced machine learning technology—an Adaptive Neural-Fuzzy Inference System—this is unique since all other systems use Bayesian Networks or other machine learning tools; (4) the classifier does not require any direct user involvement—in other systems, users must provide interruption annotations while reviewing video sessions so the system can learn; and (5) a promising direction for reasoning about interruptions for free-form tasks–this is largely an unsolved problem

POST-ADOPTION OF SOCIAL NETWORK SITES: A LITERATURE REVIEW AND A PROCESS FRAMEWORK

This article provides a comprehensive literature review about the post-adoption stage of social network sites (SNS) usage with the special focus on habitual use and terminating stages. The extant research has examined this topic mainly from two perspectives: namely, intentional and habitual. Findings from each of these two perspectives are synthesized and used to build a process model to better understand how different intentions and behaviors of users manifest in different stages of SNS post-adoption phase. The process model suggests that disturbances such as technical glitches and privacy leaks trigger users’ awareness of the ‘dark sides’ of habitual SNS use. In addition, the awareness of negative impacts of addictive use, which are perceived as threats, motivates people to switch from or quit SNS. This paper contributes to SNS research by synthesizing fragmented theoretical explanations and providing a visual tool that helps researchers to develop a deeper understanding of the dynamics in the SNS post-adoption phase. Practitioners will gain insights into how to retain existing users and better manage processes related to users who wish to quit

Anxiolytic Effect of Citrus aurantium

The objective of this study was to investigate the anxiolytic effects of the essential oil (EO) of Citrus aurantium L. in patients experiencing crack withdrawal. This was developed with internal users in therapeutic communities in Paraíba, Brazil. The test population consisted of 51 volunteers, subdivided into three groups. To elicit anxiety, the Simulated Public Speaking (SPS) method was used. Physiological measures were assessed at specific phases during the experiment using appropriate equipment. Psychological measures of anxiety were assessed using the Trait-State Anxiety Inventory (IDATE) and the Analog Smoke Scale (HAS). EO was administered by nebulization. The experiment was developed in individual sessions and consolidated to four phases. The results demonstrated that the test subjects in the groups that were given the EO maintained controlled anxiety levels during SPS, when compared to the Control Group (no treatment). Subjects who used the EO also maintained levels of “discomfort” and “cognitive impairment” during SPS. It was concluded that individuals who are experiencing internal crack cocaine withdrawal present high anxiety traits and that nebulization of the EO of Citrus aurantium L. provided an acute anxiolytic effect in crack cocaine users exposed to SPS

Channel Access and Reliability Performance in Cognitive Radio Networks:Modeling and Performance Analysis

Doktorgradsavhandling ved Institutt for Informasjons- og kommunikasjonsteknologi, Universitetet i AgderAccording to the facts and figures published by the international telecommunication union (ITU) regarding information and communication technology (ICT) industry, it is estimated that over 3.2 billion people have access to the Internet in 2015 [1]. Since 2000, this number has been octupled. Meanwhile, by the end of 2015, there were more than 7 billion mobile cellular subscriptions in the world, corresponding to a penetration rate of 97%. As the most dynamic segment in ICT, mobile communication is providing Internet services and consequently the mobile broadband penetration rate has reached 47% globally. Accordingly, capacity, throughput, reliability, service quality and resource availability of wireless services become essential factors for future mobile and wireless communications. Essentially, all these wireless technologies, standards, services and allocation policies rely on one common natural resource, i.e., radio spectrum. Radio spectrum spans over the electromagnetic frequencies between 3 kHz and 300 GHz. Existing radio spectrum access techniques are based on the fixed allocation of radio resources. These methods with fixed assigned bandwidth for exclusive usage of licensed users are often not efficient since most of the spectrum bands are under-utilized, either/both in the space domain or/and in the time domain. In reality, it is observed that many spectrum bands are largely un-occupied in many places [2], [3]. For instance, the spectrum bands which are exclusively allocated for TV broadcasting services in USA remain un-occupied from midnight to early morning according to the real-life measurement performed in [4]. In addition to the wastage of radio resources, spectrum under-utilization constraints spectrum availability for other intended users. Furthermore, legacy fixed spectrum allocation techniques are not capable of adapting to the changes and interactions in the system, leading to degraded network performance. Unlike in the static spectrum allocation, a fraction of the radio spectrum is allocated for open access as license-free bands, e.g., the industrial, scientific and medical (ISM) bands (902-928, 2400-2483.5, 5725-5850 MHz). In 1985, the federal communications commission (FCC) permitted to use the ISM bands for private and unlicensed occupancy, however, under certain restrictions on transmission power [5]. Consequently, standards like IEEE 802.11 for wireless local area networks (WLANs) and IEEE 802.15 for wireless personal area networks (WPAN) have grown rapidly with open access spectrum policies in the 2.4 GHz and 5 GHz ISM bands. With the co-existence of both similar and dissimilar radio technologies, 802.11 networks face challenges for providing satisfactory quality of service (QoS). This and the above mentioned spectrum under-utilization issues motivate the spectrum regulatory bodies to rethink about more flexible spectrum access for licenseexempt users or more efficient radio spectrum management. Cognitive radio (CR) is probably the most promising technology for achieving efficient spectrum utilization in future wireless networks

Non-invasive Brain Stimulation as a Set of Research Tools in NeuroIS: Opportunities and Methodological Considerations

NeuroIS is a growing field that builds on neuroscience to improve the understanding of human interaction with information technologies and information systems. One can investigate causal relationships between brain activity patterns, cognitive processes, and behavior in a non-invasive way via using non-invasive brain stimulation (NIBS) tools, but researchers in the neuroIS community have yet to do so. We introduce NIBS, show how it can address caveats found in current research, describe the implementation of a NIBS protocol, and assess what these tools can bring to the neuroIS field

Pragmatics and Prosody

Most of the papers collected in this book resulted from presentations and discussions undertaken during the V Lablita Workshop that took place at the Federal University of Minas Gerais, Brazil, on August 23-25, 2011. The workshop was held in conjunction with the II Brazilian Seminar on Pragmatics and Prosody. The guiding themes for the joint event were illocution, modality, attitude, information patterning and speech annotation. Thus, all papers presented here are concerned with theoretical and methodological issues related to the study of speech. Among the papers in this volume, there are different theoretical orientations, which are mirrored through the methodological designs of studies pursued. However, all papers are based on the analysis of actual speech, be it from corpora or from experimental contexts trying to emulate natural speech. Prosody is the keyword that comes out from all the papers in this publication, which indicates the high standing of this category in relation to studies that are geared towards the understanding of major elements that are constitutive of the structuring of speech

Channel assembling policies for heterogeneous fifth generation (5G) cognitive radio networks.

Doctor of Philosophy in Electronic Engineering. University of KwaZulu-Natal, Durban 2016.Abstract available in PDF file