614 research outputs found

    Real-time compression of IEC 61869-9 sampled value data

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    Fast-acting, yet cost-effective, communications is critical for smarter grid monitoring, protection, and control. This paper demonstrates a new approach for the real-time compression of Sampled Value (SV) data based on the IEC 61869-9 recommendations. This approach applies simple compression rules, yet yields excellent compression performance---typically compressing data to less than half of the original size. This leads to a significant and beneficial reduction in encoding time (in the merging unit producing the SV data) and decoding time (at the end application), as well as the main benefit of reduced Ethernet transmission times resulting from the reduced frame size. As well as reducing the absolute bandwidth requirements in typical applications, this has system-wide benefits due to reducing Ethernet queuing delays and the consequent network jitter. The approach has been validated on a real-time platform to accurately measure all contributions to the end-to-end delay. This work will help enable low-latency and bandwidth-sensitive applications involving the SV protocol, such as phasor measurement units and wide-area protection

    International spectrum management regime : is gridlock blocking flexible spectrum property rights?

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    Purpose: This paper aims to examine the influence of the international spectrum management regime on the introduction of flexibility in the national allocation of radiocommunication services. This is achieved through focusing on the main elements of the international regime. Design/methodology/approach: A qualitative inductive methodology is adopted that examines the different elements of the international radiocommunication service allocation framework. Data are drawn from 66 semi-structured interviews with key stakeholders who are actively involved in International Telecommunication Union Radiocommunication Sector discussions. Findings: The international radio regulations (RR) are perceived to be more of a framework for harmonisation that does not constrain the flexibility of countries. Countries are only restricted on their borders with their neighbours, and flexibility is already facilitated through a range of different measures. Moreover, several elements of the RR can be used to achieve both, i.e. to promote flexibility and to restrict the decisions of others. Practical implications: The international spectrum management regime is not one of the reasons for the unsuccessful practical application of the flexible spectrum property rights concept. This suggests the need for reviewing whether there still is a need for such a concept given the increasing importance of global harmonisation and economies of scales. Originality/value: This paper sheds light on spectrum property rights from the perspective of the international spectrum management regime. Such a perspective is largely overlooked in the on-going current debate

    A Communication Middleware for Ubiquitous Multimedia Adaptation Services

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    Ubiquitous services have gained increasing attention in the area of mobile communication aiming to allow service access anywhere, anytime and anyhow while keeping complexity to a minimum for both users and service providers. Ubiquitous environment features a wide range and an increasing number of access devices and network technologies. Context-aware content/service adaptation is deemed necessary to ensure best user experience. We developed an Adaptation Management Framework (AMF) Web Service which manages the complexity of dynamic and autonomous content adaptation and serves as an invisible enabler for ubiquitous service delivery. It remains challenging to manage the tasks involved in the communication between the AMF Web Service and the user's environment, typically represented by various types of intelligent agents. This work presents a middleware which manages those tasks and serves not only as a protocol gateway, but also as a message translator, a service broker, a complexity shield etc., between AMF Web Services and User Agents

    The future of vehicular security and privacy [from the guest editors]

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    This special issue of IEEE Vehicular Technology Magazine presents the latest findings and perspectives on the emerging and important area of vehicular security and privacy. Five articles form this special issue, all of which introduce a breadth of new solutions that will help the community combat the growing threat of vehicular cyberattacks. These solutions include cryptographic methods, blockchain, and new architectural considerations for CAN to protect these transportation systems both from a wireless perspective as well as from inside the vehicle itself

    Data remanence and digital forensic investigation for CUDA Graphics Processing Units

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    This paper investigates the practicality of memory attacks on commercial Graphics Processing Units (GPUs). With recent advances in the performance and viability of using GPUs for various highly-parallelised data processing tasks, a number of security challenges are raised. Unscrupulous software running subsequently on the same GPU, either by the same user, or another user, in a multi-user system, may be able to gain access to the contents of the GPU memory. This contains data from previous program executions. In certain use-cases, where the GPU is used to offload intensive parallel processing such as pattern matching for an intrusion detection system, financial systems, or cryptographic algorithms, it may be possible for the GPU memory to contain privileged data, which would ordinarily be inaccessible to an unprivileged application running on the host computer. With GPUs potentially yielding access to confidential information, existing research in the field is built upon, to investigate the practicality of extracting data from global, shared and texture memory, and retrieving this data for further analysis. These techniques are also implemented on various GPUs using three different Nvidia CUDA versions. A novel methodology for digital forensic examination of GPU memory for remanent data is then proposed, along with some suggestions and considerations towards countermeasures and anti-forensic technique

    The Diabetes Education Experience of Randomly Selected Patients Under the Care of Community Physicians

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    The purpose of this study was to describe the diabetes education and nutritional counseling received by patients under the active care of community physicians. The study population consisted of 440 patients with diabetes from the practices of 68 primary care physicians in eight Michigan communities. Fifty-eight percent of the sample reported having received diabetes education, and the mean number of years since the most recent education was 4.15 years. Sixty-six percent reported having seen a dietitian. Patients who had received diabetes education scored higher on a basic diabetes knowledge test (70% correct vs 60%) than patients who had not received diabetes education. From 1981 to 1991, a decline was observed in the percentage of patients who reported having received diabetes education (70% to 58%). Although patient education is an integral part of comprehensive diabetes care, too few patients are receiving it. Furthermore, diabetes education often results in less-than-optimal levels of knowledge. The situation has deteriorated over the past 10 years, and patients who are not on insulin typically are the least well served.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68590/2/10.1177_014572179402000506.pd

    Evaluation and application of microsatellites for population identification of Fraser River chinook salmon (Oncorhynchus tshawytscha)

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    Variation at 13 microsatellite loci was previously surveyed in approximately 7400 chinook salmon (Oncorhynchus tshawytscha) sampled from 50 localities in the Fraser River drainage in southern British Columbia. Evaluation of the utility of the microsatellite variation for population-specific stock identification applications indicated that the accuracy of the stock composition estimates generally improved with an increasing number of loci used in the estimation procedure, but an increase in accuracy was generally marginal after eight loci were used. With 10–14 populations in a simulated fishery sample, the mean error in population-specific estimated stock composition with a 50-popula-tion baseline was <1.4%. Identification of individuals to specific populations was highest for lower Fraser River and lower and North Thompson River populations; an average of 70% of the individual fish were correctly assigned to specific populations. The average error of the estimated percentage for the seven populations present in a coded-wire tag sample was 2% per population. Estimation of stock composition in the lower river commercial net fishery prior to June is of key local fishery management interest. Chinook salmon from the Chilcotin River and Nicola River drainages were important contributors to the early commercial fishery in the lower river because they comprised approximately 50% of the samples from the net fishery prior to mid April

    Design of Lipid Nanocapsule Delivery Vehicles for Multivalent Display of Recombinant Env Trimers in HIV Vaccination

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    Immunization strategies that elicit antibodies capable of neutralizing diverse virus strains will likely be an important part of a successful vaccine against HIV. However, strategies to promote robust humoral responses against the native intact HIV envelope trimer structure are lacking. We recently developed chemically cross-linked lipid nanocapsules as carriers of molecular adjuvants and encapsulated or surface-displayed antigens, which promoted follicular helper T-cell responses and elicited high-avidity, durable antibody responses to a candidate malaria antigen. To apply this system to the delivery of HIV antigens, Env gp140 trimers with terminal his-tags (gp140T-his) were anchored to the surface of lipid nanocapsules via Ni-NTA-functionalized lipids. Initial experiments revealed that the large (409 kDa), heavily glycosylated trimers were capable of extracting fluid phase lipids from the membranes of nanocapsules. Thus, liquid-ordered and/or gel-phase lipid compositions were required to stably anchor trimers to the particle membranes. Trimer-loaded nanocapsules combined with the clinically relevant adjuvant monophosphoryl lipid A primed high-titer antibody responses in mice at antigen doses ranging from 5 μg to as low as 100 ng, whereas titers dropped more than 50-fold over the same dose range when soluble trimer was mixed with a strong oil-in-water adjuvant comparator. Nanocapsule immunization also broadened the number of distinct epitopes on the HIV trimer recognized by the antibody response. These results suggest that nanocapsules displaying HIV trimers in an oriented, multivalent presentation can promote key aspects of the humoral response against Env immunogens

    The geographic basis for population structure in Fraser River chinook salmon (Oncorhynchus tshawytscha)

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    We surveyed variation at 13 microsatellite loci in approximately 7400 chinook salmon sampled from 52 spawning sites in the Fraser River drainage during 1988–98 to examine the spatial and temporal basis of population structure in the watershed. Genetically discrete chinook salmon populations were associated with almost all spawning sites, although gene flow within some tributaries prevented or limited differentiation among spawning groups. The mean FST value over 52 samples and 13 loci surveyed was 0.039. Geographic structuring of populations was apparent: distinct groups were identified in the upper, middle, and lower Fraser River regions, and the north, south, and lower Thompson River regions. The geographically and temporally isolated Birkenhead River population of the lower Fraser region was sufficiently genetically distinctive to be treated as a separate region in a hierarchial analysis of gene diversity. Approximately 95% of genetic variation was contained within populations, and the remainder was accounted for by differentiation among regions (3.1%), among populations within regions (1.3%), and among years within populations (0.5%).Analysis of allelic diversity and private alleles did not support the suggestion that genetically distinctive populations of chinook salmon in the south Thompson were the result of postglacial hybridization of ocean-type and stream-type chinook in the Fraser River drainage. However, the relatively small amount of differentiation among Fraser River chinook salmon populations supports the suggestion that gene flow among genetically distinct groups of postglacial colonizing groups of chinook salmon has occurred, possibly prior to colonization of the Fraser River drainage
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