Effective link operation duration: a new routing metric for mobile ad hoc networks

The dynamic topology of mobile ad hoc networks (MANETs) is caused by node mobility and fading of the wireless link. Link reliability is often measured by the estimated lifetime and the stability of a link. In this paper we propose that the stability of a link can be represented by the time duration in which the two nodes at each end of a link are within each other’s transmission range and the fading is above an acceptable threshold. A novel routing metric, called effective link operation duration (ELOD), is proposed and implemented into AODV (AODV-ELOD). Simulation results show that proposed AODVELOD outperforms both AODV and the Flow Oriented Routing Protocol (FORP)

An Analysis Framework for Mobility Metrics in Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) have inherently dynamic topologies. Under these difficult circumstances, it is essential to have some dependable way of determining the reliability of communication paths. Mobility metrics are well suited to this purpose. Several mobility metrics have been proposed in the literature, including link persistence, link duration, link availability, link residual time, and their path equivalents. However, no method has been provided for their exact calculation. Instead, only statistical approximations have been given. In this paper, exact expressions are derived for each of the aforementioned metrics, applicable to both links and paths. We further show relationships between the different metrics, where they exist. Such exact expressions constitute precise mathematical relationships between network connectivity and node mobility. These expressions can, therefore, be employed in a number of ways to improve performance of MANETs such as in the development of efficient algorithms for routing, in route caching, proactive routing, and clustering schemes

On multipath spatial diversity in wireless multiuser communications

The study of the spatial aspects of multipath in wireless communications environments is an increasingly important addition to the study of the temporal aspects in the search for ways to increase the utilization of the available wireless channel capacity. Traditionally, multipath has been viewed as an encumbrance in wireless communications, two of the major impairments being signal fading and intersymbol interference. However, recently the potential advantages of the diversity offered by multipath rich environments in multiuser communications have been recognised. Space time coding, for example, is a recent technique which relies on a rich scattering environment to create many practically uncorrelated signal transmission channels. Most often, statistical models have been used to describe the multipath environments in such applications. This approach has met with reasonable success but is limited when the statistical nature of a field is not easily determined or is not readily described by a known distribution. ¶ ..

Nurse Practitioner Adoption of Clinical Innovations

Adoption of clinical innovations by Nurse Practitioners (NP) is a complex phenomenon, rooted in personal values and influenced by challenges within health care environments. When clinical innovations are adopted or rejected by NPs, this decision has meaning for patients, NPs, health care agencies, and society. The decision controls the opportunity for patients to access a clinical innovation that could reduce morbidity and mortality, save money, and provide satisfaction related to the health care encounter. The purpose of the study was to increase knowledge about NP adoption of clinical innovations, particularly emotionally-laden clinical innovations. The lines of inquiry focused on what clinical innovations were thought by NPs to be emotionally-laden, whether the NPs adopted or rejected the emotionally-laden clinical innovation, the reasoning behind their decisions, and an examination of how they were involved in providing information or treatment to patients related to the innovation. A qualitative approach using grounded theory methodology was chosen. Sixteen nurse practitioner participants, practicing in adult primary care settings, were individually interviewed. Data analysis was accomplished using the constant comparative method, with an audit trail and expert review. Analysis generated a grounded theory. Philosophy of Care (context) involved the development of an individual philosophy of care and included patient choice, equal treatment, provision of information, and advocacy. Work Environment (conditions) involved aspects of the NP\u27s work environment and included work setting, economics, time, power and role, and co-workers. Innovation Adoption (process) included the aspects of discovery, evaluation, and actual adoption or rejection of the innovation. Doing the Right Thing was a sub theme of the process. The Adoption Spectrum showed that innovation adoption could be consistent, intermittent, or conditional. Innovation rejection could be overt or covert. Values Continuum: Congruence to Dissonance (consequences) involved aspects of being at risk, being ambivalent, and being satisfied. Congruence occurred when NP personal and professional values were in agreement with the perspectives of the patient and agency; dissonance occurred when values were in conflict. Support of timely and appropriate adoption of clinical knowledge benefits society. A sophisticated understanding of how new knowledge is incorporated or rejected by NPs is a prerequisite to the intelligent development of nursing research and education

The War On Stigma: Examining Mental Illness Stigma in the U.S. Military

Current research suggests up to 43% of United States and 37% of United Kingdom troops returning home from war have experienced some type of mental health issue(s) (Iversen, Staden, Hughes et al., 2009; Sareen, Cox, Afifi et al., 2007). Literature also suggests 60% of military personnel who experience these mental health problems do not seek help, yet many of them could benefit from professional treatment (Sharp et al., 2014). Those wishing to seek mental health treatment likely face several barriers, such as lack of qualified professionals or service availability, but the stigma of mental illness may be the most pervasive (Acosta et al., 2014). Previous research has failed to examine the specific mental health needs and well-being of active-duty personnel, while only a breadth of previous literature exists examining stigma toward mental health in the military (Acosta et al., 2014; Britt et al., 2007; Sharp et al., 2014). The purpose of the study was to examine first-hand, active, and inactive military personnel experiences with mental illness and the quality of mental health services provided to these individuals. Results indicated that men reported greater stigmatic attitudes towards those with a mental illness more frequently than women and men also endorsed more stereotypes toward those with a mental illness when compared to women

Habitat selection and habitat use of gray foxes (Urocyon cinereoargenteus) on trespass cannabis grows.

Trespass cannabis grow sites, otherwise known as illegal cultivation sites on public lands, are extremely hazardous to the environment and can severely impact wildlife movement and behavior. Trespass grow sites are dangerous to wildlife as they negatively impact the quality of habitat and wildlife behavior through habitat modification, pesticide use, discarding of trash, and poaching on national forests. I researched gray fox habitat selection and habitat use at six different grow sites in the Klamath National Forest and Shasta-Trinity National Forest in northwestern California. I deployed GPS collars on three gray foxes at two of those grow sites and three gray foxes at two reference sites between September 2020 and April 2021. I used autocorrelated kernel density estimates and resource-selection functions, using generalized linear models, to evaluate gray fox habitat selection and found that two of the three gray foxes selected trespass grow sites when grow sites were found within their home ranges. I evaluated the combined data of all six collared foxes in regard to environmental characteristics and found that foxes prefer areas with a greater aspect, specifically those facing south, southwest, and west. I deployed eighty-eight game cameras across six trespass grow sites to collect photo and video media for 22 months. I used the Shapiro Wilks Normality test and the Mann Whitney U test to compare gray fox behavior across different grow site features. There were a higher number of detections of gray foxes at process areas, camp sites, toxicant piles, and trash pits. Locomotion behavior was observed at similar levels across all site features. Vigilant behaviors were most observed at toxicant piles, camp sites, trails, and cultivation plots. Marking behaviors were most common at process areas, trash pits, and toxicant piles. The most recorded behavior was locomotion, followed by vigilance, scent marking, and then feeding, with no documented behaviors of resting. Proportionally more foxes were recorded at camp sites, toxicant piles, trash pits, and process areas than in cultivation plots or along trails, which signifies that gray foxes utilize areas hypothesized as more attractive within the grow site. This research shows that foxes use trespass grows, though future researchers are encouraged to include a larger sample size collared gray foxes and of the cultivation plot and trail locations. Resource agencies must prioritize elimination and reclamation of these sites. Otherwise, wildlife will continue to suffer direct and indirect effects as they utilize the trespass grow sites present in their home ranges

Cache timeout strategies for on-demand routing in MANETs

Varying the route caching scheme can significantly change network performance for on-demand routing protocols in mobile ad hoc networks (MANETs). Initial route caching schemes retain paths or links until they are shown to be broken. However, stale routing information can degrade network performance with latency and extra routing overhead. Therefore, more recent caching schemes delete links at some fixed time after they enter the cache. This paper proposes using either the expected path duration or the link residual time as the link cache timeout. These mobility metrics are theoretically calculated for an appropriate random mobility model. Simulation results in NS2 show that both of the proposed link caching schemes can improve network performance in the dynamic source routing protocol (DSR) by reducing dropped data packets, latency and routing overhead, with the link residual time scheme out-performing the path duration scheme.IEEE, South Australian Sectio

Violence Against Black People in America: A ClioVis Timeline

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