Cognitive relay nodes for airborne LTE emergency networks

This paper is proposing a novel concept of Cognitive Relay Node for intelligently improving the radio coverage of an airborne LTE emergency network, considering the scenarios outlined in the ABSOLUTE research project. The proposed network model was simulated comparing the different cases of deploying relay nodes to complement the coverage of an aerial LTE network. Simulation results of the proposed Cognitive Relay Nodes show significant performance improvement in terms of radio coverage quantified by the regional outage probability enhancement. Also, this paper is presenting the methodology and results of choosing the optimum aerial eNodeB altitude

Aerial-terrestrial communications: terrestrial cooperation and energy-efficient transmissions to aerial-base stations

Hybrid aerial-terrestrial communication networks based on low-altitude platforms are expected to meet optimally the urgent communication needs of emergency relief and recovery operations for tackling large-scale natural disasters. The energy-efficient operation of such networks is important given that the entire network infrastructure, including the battery-operated ground terminals, exhibits requirements to operate under power-constrained situations. In this paper, we discuss the design and evaluation of an adaptive cooperative scheme intended to extend the survivability of the battery-operated aerial-terrestrial communication links. We propose and evaluate a real-time adaptive cooperative transmission strategy for dynamic selection between direct and cooperative links based on the channel conditions for improved energy efficiency. We show that the cooperation between mobile terrestrial terminals on the ground could improve energy efficiency in the uplink, depending on the temporal behavior of the terrestrial and aerial uplink channels. The corresponding delay in having cooperative (relay-based) communications with relay selection is also addressed. The simulation analysis corroborates that the adaptive transmission technique improves overall energy efficiency of the network whilst maintaining low latency, enabling real-time applications

Comprehensive survey on quality of service provisioning approaches in cognitive radio networks : part one

Much interest in Cognitive Radio Networks (CRNs) has been raised recently by enabling unlicensed (secondary) users to utilize the unused portions of the licensed spectrum. CRN utilization of residual spectrum bands of Primary (licensed) Networks (PNs) must avoid harmful interference to the users of PNs and other overlapping CRNs. The coexisting of CRNs depends on four components: Spectrum Sensing, Spectrum Decision, Spectrum Sharing, and Spectrum Mobility. Various approaches have been proposed to improve Quality of Service (QoS) provisioning in CRNs within fluctuating spectrum availability. However, CRN implementation poses many technical challenges due to a sporadic usage of licensed spectrum bands, which will be increased after deploying CRNs. Unlike traditional surveys of CRNs, this paper addresses QoS provisioning approaches of CRN components and provides an up-to-date comprehensive survey of the recent improvement in these approaches. Major features of the open research challenges of each approach are investigated. Due to the extensive nature of the topic, this paper is the first part of the survey which investigates QoS approaches on spectrum sensing and decision components respectively. The remaining approaches of spectrum sharing and mobility components will be investigated in the next part

Global change data sets: Excerpts from the Master Directory, version 2.0

The recent awakening to the reality of human-induced changes to the environment has resulted in an organized effort to promote global change research. The goal of this research as outlined by NASA's Earth System Science Committee (Earth System Science: A closer View, 1988) is to understand the entire Earth system on a global scale by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to evolve on all timescales. The practical result is the capacity to predict that evolution over the next decade to century. Key variables important for the study of global change include external forcing factors (solar radiance, UV flux), radiatively and chemically important trace species (CO2, CH4, N2O, etc.), atmospheric response variables (temperature, pressure, winds), landsurface properties (river run-off, snow cover, albedo, soil moisture, vegetation cover), and oceanic variables (sea surface temperature, sea ice extent, sea level ocean wind stress, currents, chlorophyll, biogeochemical fluxes). The purpose of this document is to identify existing data sets available (both remotely sensed and in situ data) covering some of these variables. This is not intended to be a complete list of global change data, but merely a highlight of what is available. The information was extracted from the Master Directory (MD), an on-line scientific data information service which may be used by any researcher. This report contains the coverage dates for the data sets, sources (satellites, instruments) of the data and where they are archived

Performance management in Thai R&D organizations : exploring the interplay between R&D institutions and R&D contexts

Measuring research and development (R&D) performance has become a fundamental concern for R&D organisations. However, the complexity of measurement problems in R&D organisations has resulted in a situation where there is an excess of literature around the areas of R&D measurement, and yet a scarcity of generally accepted measurement approaches (Brown & Gobeli, 1992). This might be because the design of performance measurement (PM) for an R&D organisation combines several interrelated contexts that make each R&D measurement unique. This thesis, therefore, reviews several major R&D distinctions which should be taken into account when the R&D PM design is considered. These considerations are R&D measurement levels and perspectives, R&D key measures, R&D key drivers, and types of R&D institutions.;Taking a quality-based approach, the thesis combines several techniques, i.e. in-depth interviews, cognitive mapping interviews, document analysis, multiple case studies, and cross-case analysis. The interviews involve 30 respondents who are all experienced in R&D management in four different Thai R&D institutes, under the Ministry of Science and Technology.;The results indicate issues in three areas of investigation. First, the four cases studied measure R&D performance at different levels, for different purposes, and applying different measures and techniques. At a corporate level, instead of emphasising financial areas, the output measurement seems to be significant, as well as deliberative to quantitative methods. Meanwhile, at a team level, the measures highlight both quantitative and qualitative measures, for the purpose of monitoring the process and progress of research.;Second, the output mixes, stage of R&D, and sources of research questions could lead to the identification of three major types of R&D organisations: discipline-based, profession-based, and domain-based. The R&D measures that a firm applies seem to be interrelated with the type of R&D institution that firm represents.;Finally, the main key driver in this study is R&D collaboration. However, collaboration functions differ according to the different types of R&D organisations. A discipline-based organisation tends to use collaboration as a tool to explore new knowledge and to strengthen the firm's competency, whereas a profession-based organisation tends to use collaboration to gain market information and increase its ability to utilise R&D.;The study developed implications of both theoretical and managerial importance, identifying patterns of interrelationship between R&D institutions and key performance measures, and between R&D institutions and their collaboration mechanisms. Additionally, the main managerial implication could benefit R&D management practitioners, R&D managers, and R&D policymakers. Overall, the study's results demonstrate the importance of understanding the constraints of each R&D measurement context, i.e. levels of measurement, areas of measurement, and stages of R&D, for the performance measurement system.;Also, this study shows that each type of R&D institute may significantly be interrelated with other features, i.e. with key measures, and with key driver's mechanisms. Conducive to measuring and managing R&D performance efficiently, managers may realise the unique role of each type of R&D organisation (as well as its key measures and performance drivers) and design their performance measurement accordingly. Therefore, the benefits of this study may be seen as practical knowledge which could be employed to design R&D PM and, ultimately, to complement a strategic formulation to improve a firm's R&D performance.Measuring research and development (R&D) performance has become a fundamental concern for R&D organisations. However, the complexity of measurement problems in R&D organisations has resulted in a situation where there is an excess of literature around the areas of R&D measurement, and yet a scarcity of generally accepted measurement approaches (Brown & Gobeli, 1992). This might be because the design of performance measurement (PM) for an R&D organisation combines several interrelated contexts that make each R&D measurement unique. This thesis, therefore, reviews several major R&D distinctions which should be taken into account when the R&D PM design is considered. These considerations are R&D measurement levels and perspectives, R&D key measures, R&D key drivers, and types of R&D institutions.;Taking a quality-based approach, the thesis combines several techniques, i.e. in-depth interviews, cognitive mapping interviews, document analysis, multiple case studies, and cross-case analysis. The interviews involve 30 respondents who are all experienced in R&D management in four different Thai R&D institutes, under the Ministry of Science and Technology.;The results indicate issues in three areas of investigation. First, the four cases studied measure R&D performance at different levels, for different purposes, and applying different measures and techniques. At a corporate level, instead of emphasising financial areas, the output measurement seems to be significant, as well as deliberative to quantitative methods. Meanwhile, at a team level, the measures highlight both quantitative and qualitative measures, for the purpose of monitoring the process and progress of research.;Second, the output mixes, stage of R&D, and sources of research questions could lead to the identification of three major types of R&D organisations: discipline-based, profession-based, and domain-based. The R&D measures that a firm applies seem to be interrelated with the type of R&D institution that firm represents.;Finally, the main key driver in this study is R&D collaboration. However, collaboration functions differ according to the different types of R&D organisations. A discipline-based organisation tends to use collaboration as a tool to explore new knowledge and to strengthen the firm's competency, whereas a profession-based organisation tends to use collaboration to gain market information and increase its ability to utilise R&D.;The study developed implications of both theoretical and managerial importance, identifying patterns of interrelationship between R&D institutions and key performance measures, and between R&D institutions and their collaboration mechanisms. Additionally, the main managerial implication could benefit R&D management practitioners, R&D managers, and R&D policymakers. Overall, the study's results demonstrate the importance of understanding the constraints of each R&D measurement context, i.e. levels of measurement, areas of measurement, and stages of R&D, for the performance measurement system.;Also, this study shows that each type of R&D institute may significantly be interrelated with other features, i.e. with key measures, and with key driver's mechanisms. Conducive to measuring and managing R&D performance efficiently, managers may realise the unique role of each type of R&D organisation (as well as its key measures and performance drivers) and design their performance measurement accordingly. Therefore, the benefits of this study may be seen as practical knowledge which could be employed to design R&D PM and, ultimately, to complement a strategic formulation to improve a firm's R&D performance

Method and system for spatially variable rate application of agricultural chemicals based on remotely sensed vegetation data

Remotely sensed spectral image data are used to develop a Vegetation Index file which represents spatial variations of actual crop vigor throughout a field that is under cultivation. The latter information is processed to place it in a format that can be used by farm personnel to correlate and calibrate it with actually observed crop conditions existing at control points within the field. Based on the results, farm personnel formulate a prescription request, which is forwarded via email or FTP to a central processing site, where the prescription is prepared. The latter is returned via email or FTP to on-side farm personnel, who can load it into a controller on a spray rig that directly applies inputs to the field at a spatially variable rate

Detection, monitoring and management of small water bodies:: A case study of Shahjadpur Thana, Sirajgonj district, Bangladesh

Bangladesh is a low-lying flood prone deltaic plain. Excavations are needed to create raised land for safe flood-free homesteads and water bodies for irrigation, and these result in the creation of doba, pukur, dighi and jola. All of these types of small water bodies are almost equally distributed all over the country, except for the heel, which is a natural, saucer shaped depression. For every eight people there is approximately an acre of small water bodies, which range in size from 25-400 sq.m. (doba), 150-1000 sq.m. (pukur), >750 sq.m. (dighi), >2000 sq.m. (jola) and >1000 sq.m. (heel). These small water bodies are commonly used for drinking, bathing and washing, fisheries and aquaculture, duck raising, irrigation, cattle feeding and washing. Despite the importance of small water bodies to the local economy there is no up to date inventory. For this purpose, in my research I have employed integrated participatory remote sensing, GIS and socio-cultural approaches. Although these have not been used before in Bangladesh, 1 argue that they are ideal for effective resource management and sustainable development planning. This research investigated the historical development of the present spatial distribution and use patterns of SWB using Remote Sensing and GIS. This was at a regional scale in four mouzas of Shahjadpur Thana. The data sources were topographical maps, aerial photographs, satellite images, agricultural census data, in-depth questionnaire, focus group meetings and interviewing key informants. An integrated RS-GIS and social sciences methodology was employed to produce maps of change and overlays of the socio-cultural factors involved. Results show that the doba, pukur and dighi, when these are not obstructed by surrounding vegetation, can be detected easily in high resolution panchromatic CORONA satellite photography, IRS-ID Panchromatic image and aerial photography. Comparatively large pukurs, dighis and all jo las and heels are detected in all other optical sensors and the SIR-C radar imagery. Multi-temporal images are helpful for identifying the different types of small water bodies as well separating those from other seasonal large water bodies and flooded areas. It is hoped that the proposed computer assisted participatory management system, including some locally specific guidelines, may be applicable for the planning of other thanas (total 490) in Bangladesh. The proposed management system will facilitate the integration of local planning with the national level planning process, which has not been possible hitherto

Endosymbiosis before eukaryotes: mitochondrial establishment in protoeukaryotes

Endosymbiosis and organellogenesis are virtually unknown among prokaryotes. The single presumed example is the endosymbiogenetic origin of mitochondria, which is hidden behind the event horizon of the last eukaryotic common ancestor. While eukaryotes are monophyletic, it is unlikely that during billions of years, there were no other prokaryote–prokaryote endosymbioses as symbiosis is extremely common among prokaryotes, e.g., in biofilms. Therefore, it is even more precarious to draw conclusions about potentially existing (or once existing) prokaryotic endosymbioses based on a single example. It is yet unknown if the bacterial endosymbiont was captured by a prokaryote or by a (proto-)eukaryote, and if the process of internalization was parasitic infection, slow engulfment, or phagocytosis. In this review, we accordingly explore multiple mechanisms and processes that could drive the evolution of unicellular microbial symbioses with a special attention to prokaryote–prokaryote interactions and to the mitochondrion, possibly the single prokaryotic endosymbiosis that turned out to be a major evolutionary transition. We investigate the ecology and evolutionary stability of inter-species microbial interactions based on dependence, physical proximity, cost–benefit budget, and the types of benefits, investments, and controls. We identify challenges that had to be conquered for the mitochondrial host to establish a stable eukaryotic lineage. Any assumption about the initial interaction of the mitochondrial ancestor and its contemporary host based solely on their modern relationship is rather perilous. As a result, we warn against assuming an initial mutually beneficial interaction based on modern mitochondria–host cooperation. This assumption is twice fallacious: (i) endosymbioses are known to evolve from exploitative interactions and (ii) cooperativity does not necessarily lead to stable mutualism. We point out that the lack of evidence so far on the evolution of endosymbiosis from mutual syntrophy supports the idea that mitochondria emerged from an exploitative (parasitic or phagotrophic) interaction rather than from syntrophy