Techno-economic evaluation of cognitive radio in a factory scenario

Wireless applications gradually enter every aspect of our life. Unfortunately, these applications must reuse the same scarce spectrum, resulting in increased interference and limited usability. Cognitive Radio proposes to mitigate this problem by adapting the operational parameters of wireless devices to varying interference conditions. However, it involves an increase in cost. In this paper we examine the economic balance between the added cost and the increased usability in one particular real-life scenario. We focus on the production floor of an industrial installation where wireless sensors monitor production machinery, and a wireless LAN is used as the data backbone. We examine the effects of implementing dynamic spectrum access by means of ideal RE sensing, and model the benefit in terms of increased reliability and battery lifetime. We estimate the financial cost of interference and the potential gain, and conclude that cognitive radio can bring business gains in real-life applications

Allorecognition in the Tasmanian Devil (Sarcophilus harrisii), an Endangered Marsupial Species with Limited Genetic Diversity

Tasmanian devils (Sarcophilus harrisii) are on the verge of extinction due to a transmissible cancer, devil facial tumour disease (DFTD). This tumour is an allograft that is transmitted between individuals without immune recognition of the tumour cells. The mechanism to explain this lack of immune recognition and acceptance is not well understood. It has been hypothesized that lack of genetic diversity at the Major Histocompatibility Complex (MHC) allowed the tumour cells to grow in genetically similar hosts without evoking an immune response to alloantigens. We conducted mixed lymphocyte reactions and skin grafts to measure functional MHC diversity in the Tasmanian devil population. The limited MHC diversity was sufficient to produce measurable mixed lymphocyte reactions. There was a wide range of responses, from low or no reaction to relatively strong responses. The highest responses occurred when lymphocytes from devils from the east of Tasmania were mixed with lymphocytes from devils from the west of Tasmania. All of the five successful skin allografts were rejected within 14 days after surgery, even though little or no MHC I and II mismatches were found. Extensive T-cell infiltration characterised the immune rejection. We conclude that Tasmanian devils are capable of allogeneic rejection. Consequently, a lack of functional allorecognition mechanisms in the devil population does not explain the transmission of a contagious cancer

Hexactinellid Sponge Reefs on the Canadian Continental Shelf: A Unique "Living Fossil"

Globally unique hexactinellid (siliceous) sponge reefs, found in deep (200 m), glacially scoured troughs of the western Canadian continental shelf, have been explored by a manned submersible. Submersible observations and geophysical data allow examination of the physical and biological processes that have shaped the sponge reefs, which began to form about 9 thousand years (k.y.) ago. The mounds (bioherms) and sheet-like accumulations (biostromes) cover a low-angle, non-depositional, iceberg-scoured seafloor, relict since the déglaciation of the region. Biohermal structures are up to 19 m in height, and are covered with hexactinosan sponges up to 1.5 m tall, creating abenthic habitat that discontinously covers roughly 700 km2. Similar to extinct siliceous sponge reefs, mud mounds, and reef mounds that were widespread during the Mesozoic, the modern reefs are like a"living fossil" and provide a unique modern analogue. Fishing activities, especially trawling or bottom dragging, have damaged the slow-growing reefs insome areas. Résumé Uniques au monde, les récifs d'épongés d'hexactinellides (siliceux) qui se trouvent à 200 m de profondeur dans des fosses d'abrasion glaciaires du plateau continental de l'Ouest du Canada, ont été explorés à partir de sous-marins habités. Les observations sous-marines et les données de géophysique permettent d'étudier les mécanismes physiques et biologiques qui ont présidé à l'édification des récifs d'épongés qui ont commencé à se former aux environs de 9 ka  P. Ces édifices récifaux en amas (biohermes), et en couches (biostromes) recouvrent un fond marin légèrement incliné par l'abrasion d'icebergs post-glaciaires. Ces biohermes ont jusqu'à 19 m de hauteur et sont recouverts d'une couche de 1,5 m de hauteur d'épongés hexactinellidiennes, forment un habitat couvrant de manière discontinue une surface de 700 km2. Semblables à ces récifs d'épongés très répandus au Mésozoïques, amas boueux et amas récifaux, les récifs modernes sont de véritables fossiles vivants, et sont à ce titre forts utiles pour la compréhension de leurs contreparties fossiles. Par endroits, les activités de pêche industrielle, particulièrement le chalutage ou le dragage de fond ont endommagé ces édifices récifales à croissantes lentes

Geolocation database beyond TV white spaces? : Matching applications with database requirements

Taikomosios informatikos katedraVytauto Didžiojo universiteta

Techno-Economic Evaluation of Cognitive Radio in a Factory Scenario

Abstract. Wireless applications gradually enter every aspect of our life. Unfortunately, these applications must reuse the same scarce spectrum, resulting in increased interference and limited usability. Cognitive Radio proposes to mitigate this problem by adapting the operational parameters of wireless devices to varying interference conditions. However, it involves an increase in cost. In this paper we examine the economic balance between the added cost and the increased usability in one particular real-life scenario. We focus on the production floor of an industrial installation -where wireless sensors monitor production machinery, and a wireless LAN is used as the data backbone. We examine the effects of implementing dynamic spectrum access by means of ideal RF sensing, and model the benefit in terms of increased reliability and battery lifetime. We estimate the financial cost of interference and the potential gain, and conclude that cognitive radio can bring business gains in real-life applications

Aerosol-type-dependent lidar ratios observed with Raman lidar

[1] We summarize our Raman lidar observations which were carried out in Europe, Asia, and Africa during the past 10 years, with focus on particle extinction-to-backscatter ratios ( lidar ratios) and (A) over circle ngstrom exponents. For the first time, we present statistics on lidar ratios for almost all climatically relevant aerosol types solely based on Raman lidar measurements. Sources of continental particles were in North America and Europe, the Sahara, and south and Southeast and east Asia. The North Atlantic Ocean, and the tropical and South Indian Ocean were the sources of marine particles. The statistics are complemented with lidar ratios describing aged forest fire smoke and pollution from polar regions ( Arctic haze) after long-range transport. In addition, we present particle (A) over circle ngstrom exponents for the wavelength range from 355 to 532 nm and from 532 to 1064 nm. We compare our data set of lidar ratios to the recently published AERONET ( Aerosol Robotic Network) lidar ratio climatology. That climatology is based on aerosol scattering modeling in which AERONET Sun photometer observations serve as input. Raman lidar measurements of extinction-to-backscatter ratios of Saharan dust and urban aerosols differ significantly from the numbers obtained with AERONET Sun photometers. There are also differences for some of the (A) over circle ngstrom exponents. Further comparison studies are needed to reveal the reason for the observed differences.Peer reviewe