A Secure Group Communication Architecture for a Swarm of Autonomous Unmanned Aerial Vehicles

This thesis investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MatLab. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the swarm size, swarm mobility, multicast group join and departure rates are varied. The metrics include the total keys distributed over the simulation period, the average number of times an individual UAV must rekey, the average bandwidth used to rekey the swarm, and the average percentage of battery consumed by a UAV to rekey over the simulation period. The proposed security architecture can successfully be applied to a swarm of autonomous UAVs using current technology. The proposed architecture is more efficient and scalable than the other tested and commonly-used architectures. Over all the tested configurations, the proposed architecture distributes 55.2 – 94.8% fewer keys, rekeys 59.0 - 94.9% less often per UAV, uses 55.2 - 87.9% less bandwidth to rekey, and reduces the battery consumption by 16.9 – 85.4%

A Secure Group Communication Architecture for Autonomous Unmanned Aerial Vehicle

This paper investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MATLAB. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the swarm size, swarm mobility, multicast group join and departure rates are varied. The metrics include the total keys distributed over the simulation period, the average number of times an individual UAV must rekey, the average bandwidth used to rekey the swarm, and the average percentage of battery consumed by a UAV to rekey over the simulation period. The proposed security architecture can successfully be applied to a swarm of autonomous UAVs using current technology. The proposed architecture is more efficient and scalable than the other tested and commonly used architectures. Over all the tested configurations, the proposed architecture distributes 55.2–94.8% fewer keys, rekeys 59.0–94.9% less often per UAV, uses 55.2–87.9% less bandwidth to rekey, and reduces the battery consumption by 16.9–85.4%

A Secure Group Communication Architecture for Autonomous Unmanned Aerial Vehicles

This paper investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MATLAB. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the swarm size, swarm mobility, multicast group join and departure rates are varied. The metrics include the total keys distributed over the simulation period, the average number of times an individual UAV must rekey, the average bandwidth used to rekey the swarm, and the average percentage of battery consumed by a UAV to rekey over the simulation period. The proposed security architecture can successfully be applied to a swarm of autonomous UAVs using current technology. The proposed architecture is more efficient and scalable than the other tested and commonly used architectures. Over all the tested configurations, the proposed architecture distributes 55.2–94.8% fewer keys, rekeys 59.0–94.9% less often per UAV, uses 55.2–87.9% less bandwidth to rekey, and reduces the battery consumption by 16.9–85.4%

Landscape approaches for ecosystem management in Mediterranean Islands

This book presents a series of essays, drawing on the twm concepts of ecosystem management and landscape approaches, to elucidate and reflect on the present situation and future evolution of Mediterranean islands. This publication brings together contributions from Mediterranean individuals, non-Mediterranean individuals, islanders and non-islanders there is, after all, no geographical limit on who and what we can learn from. The essays presented here each contribute a specific perspective on the future evolution of Mediterranean islands. This book presents a series of essays, drawing on the twin concepts of ecosystem management and landscape approaches, to elucidate and reflect on the present situation and future evolution of Mediterranean islands. This publication brings together contributions from Mediterranean individuals, non-Mediterranean individuals, islanders and non-islanders; there is, after all, no geographical limit on who and what we can learn from. The essays presented here each contribute a specific perspective on the future evolution of Mediterranean islands. Following this introductory chapter, the first section of the book focuses on the contributions that can be made by the discipline of landscape ecology. loannis Vogiatzakis and Geoffrey Griffiths first explain the concepts and relevance of landscape ecology, also presenting and discussing a range of applied tools that can facilitate landscape planning in Mediterranean islands. Louis F. Cassar then reviews the 'offshoot' discipline of restoration ecology, making a strong case for offsetting the environmental damage inflicted on natural ecosystems over millennia of human occupation, with constructive efforts to effectively restore and/or rehabilitate ecosystems. The two following chapters bring the socio-economic dimension into the discussion. Godfrey Baldacchino first presents two contrasting paradigms for the development of island territories, reviewing the dual influences of ecological and economic factors, and exploring ways in which the two can be brought together in successful development strategies. Gordon Cordina and Nadia Farrugia then address the demographic dimension of development, presenting a model to explain the economic costs of high population densities on islands. The third block of chapters expands on the relevance of social and cultural dynamics to the management of Mediterranean Islands. Isil Cakcï, Nur Belkayali and Ilkden Tazebay explain the evolution of the concept of a 'cultural landscape', focusing on the challenges of managing change in landscapes with strong heritage values. The chapter concludes with a case study on the Turkish island of Gökçeada (lmbros), which is experiencing major challenges in balancing the conservation of a cultural landscape on the one hand, and the management of inevitable change, on the other. Elisabeth Conrad then discusses the role of social capital in managing the landscape resources of Mediterranean islands, reviewing the potential for this intangible social fabric to facilitate or impede the sustainable evolution of island territories. The fourth section includes four chapters, each of which addresses a different aspect relevant to policy development and implementation in Mediterranean islands. Salvino Busuttil presents an essay outlining the political influences on the management of coastal landscapes, the latter so relevant to Mediterranean island territories. The essay derives from the author's professional experience in various policy-related institutions for environmental management within the Mediterranean region. Maggie Roe then reflects on issues of landscape sustainability, focusing on the neglected aspect of intelligence. She discusses ways in which landscape research, knowledge and understanding can feed directly into frameworks for 'sustainable' landscape planning. In the subsequent chapter, Adrian Phillips takes from his substantial experience with international landscape policy, reviewing the gradual emergence of international and national landscape 'tools', to draw out lessons for application in Mediterranean islands. In the final chapter of this section, Riccardo Priore and Damiano Galla present a comprehensive discussion of the European Landscape Convention, the first international instrument to focus exclusively on landscape. The authors explain the innovative character of this convention, and discuss its potential implementation in Mediterranean islands. The publication concludes with a series of case studies, highlighting specific constraints, experiences and opportunities in different Mediterranean islands. Theano Terkenli explores the landscapes of tourism in Mediterranean islands - perhaps no other industry has played such a fundamental role in shaping the evolution of Mediterranean landscapes in recent years. The author reviews the theoretical relationship between landscape and tourism across Mediterranean islands, before focusing on the specific case of the Greek Cycladic islands. In the following chapter, Alex Camilleri, Isabella Colombini and Lorenzo Chelazzi present an in-depth review of the context and challenges being faced on a number of minor Mediterranean islands, namely those of the Tuscan archipelago (Elba, Giglio, Capraia, Montecristo, Pianosa, Gorgona and Giannutri), and Comino, the latter forming part of the Maltese archipelago. The comparison between these various islands enables an appreciation of both commonalities across these islands, as well as considerations that are specific to the context of each in dividual island. JeremyBoissevain then adopts an anthropological lens to review the cautionary tale of landscape change in Malta, exploring underlying causes of landscape destruction and limited civil engagement. In the subsequent chapter, Jala Makhzoumi outlines the richness of Mediterranean islands' rural landscapes, focusing on olive landscapes in Cyprus. Her research demonstrates the economic and ecological robustness of various olive cultivation practices, and whilst warning of several threats to such sustainable regimes, she outlines strategies for reconfiguring our approach to rural heritage, in order to integrate such assets into sustainable development strategies. Finally, Stephen Morse concludes the section with an evaluation of sustainable development indicators, and the contribution that these can make towards enhancing the management of Mediterranean island territories. He illustrates his arguments with reference to the two island states of Malta and Cyprus. To conclude, in the final chapter of this publication, we review key insights emerging from the various chapters, and summarize considerations for ecosystem management and sustainable development in Mediterranean Islands. We truly hope that this publication makes some contribution towards safeguarding the "magic' of Mediterranean islands, whilst embracing their dynamic characteristics.Published under the patronage of UNESCO and with the support of the Maltese National Commission for UNESCOpeer-reviewe

The Heavy Photon Search test detector

The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiment׳s technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in the e+e− invariant mass spectrum above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW04 crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e+e− pairs requires the first layer of silicon sensors be placed only 10 cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. Accordingly, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab

Human Impacts on Forest Biodiversity in Protected Walnut-Fruit Forests in Kyrgyzstan

We used a spatially explicit model of forest dynamics, supported by empirical field data and socioeconomic data, to examine the impacts of human disturbances on a protected forest landscape in Kyrgyzstan. Local use of 27 fruit and nut species was recorded and modeled. Results indicated that in the presence of fuelwood cutting with or without grazing, species of high socioeconomic impor- tance such as Juglans regia, Malus spp., and Armeniaca vulgaris were largely eliminated from the landscape after 50–150 yr. In the absence of disturbance or in the presence of grazing only, decline of these species occurred at a much lower rate, owing to competi- tive interactions between tree species. This suggests that the current intensity of fuelwood harvesting is not sustainable. Conversely, cur- rent grazing intensities were found to have relatively little impact on forest structure and composition, and could potentially play a positive role in supporting regeneration of tree species. These results indicate that both positive and negative impacts on biodiversity can arise from human populations living within a protected area. Potentially, these could be reconciled through the development of participatory approaches to conservation management within this reserve, to ensure the maintenance of its high conservation value while meeting human needs

ER and HER2 expression are positively correlated in HER2 non-overexpressing breast cancer

PMCID: PMC3446380This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

HIV Prevalence and Associated Risk Factors among Individuals Aged 13-34 Years in Rural Western Kenya

OBJECTIVES: To estimate HIV prevalence and characterize risk factors among young adults in Asembo, rural western Kenya. DESIGN: Community-based cross-sectional survey. METHODS: From a demographic surveillance system, we selected a random sample of residents aged 13-34 years, who were contacted at home and invited to a nearby mobile study site. Consent procedures for non-emancipated minors required assent and parental consent. From October 2003 - April 2004, consenting participants were interviewed on risk behavior and tested for HIV and HSV-2. HIV voluntary counseling and testing was offered. RESULTS: Of 2606 eligible residents, 1822 (70%) enrolled. Primary reasons for refusal included not wanting blood taken, not wanting to learn HIV status, and partner/parental objection. Females comprised 53% of 1762 participants providing blood. Adjusted HIV prevalence was 15.4% overall: 20.5% among females and 10.2% among males. HIV prevalence was highest in women aged 25-29 years (36.5%) and men aged 30-34 years (41.1%). HSV-2 prevalence was 40.0% overall: 53% among females, 25.8% among males. In multivariate models stratified by gender and marital status, HIV infection was strongly associated with age, higher number of sex partners, widowhood, and HSV-2 seropositivity. CONCLUSIONS: Asembo has extremely high HIV and HSV-2 prevalence, and probable high incidence, among young adults. Further research on circumstances around HIV acquisition in young women and novel prevention strategies (vaccines, microbicides, pre-exposure prophylaxis, HSV-2 prevention, etc.) are urgently needed

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes