703 research outputs found
Dynamic load management and optimum sizing of stand-alone hybrid PV/Wind system.
Simulation algorithms for the sizing of stand-alone hybrid PV/Wind systems are a powerful tool in evaluating the optimum configuration that would cover the energy demand with a predefined reliability level at the lowest cost. Several parameters such as the interval of the simulation (day, day-night, hourly) and the consumption profile may significantly affect the optimum configuration. This paper examines the effect of these parameters within an optimum sizing simulation algorithm developed. The effect of these parameters was particularly evident at low battery capacities, which involve optimum configurations resulting in minimum cost. Furthermore, shift-able loads in the hourly-based weekly profile assumed in this study were identified, and a dynamic load management functionality was developed. In this approach, loads that could be shifted through time were dynamically allocated during periods of excess energy production by the hybrid PV/Wind system. The results showed an increase in system reliability from 95% to 97% when load shifting was introduced. Finally, sizing the system for only the static (non-shift-able loads) proved to withstand the addition of the extra shift-able loads while retaining the 95% reliability level when the load management functionality was introduced. Thus, a smaller installation with lower cost is achieved
Distributed, end-to-end verifiable, and privacy-preserving internet voting systems
We present the D-DEMOS suite of distributed, privacy-preserving, and end-to-end verifiable e-voting systems; one completely asynchronous and one with minimal timing assumptions but better performance. Their distributed voting operation is human verifiable; a voter can vote over the web, using an unsafe web client stack, without sacrificing her privacy, and get recorded-as-cast assurance. Additionally, a voter can outsource election auditing to third parties, still without sacrificing privacy. We provide a model and security analysis of the systems, implement prototypes of the complete systems, measure their performance experimentally, demonstrate their ability to handle large-scale elections, and demonstrate the performance trade-offs between the two versions
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Dialysis Access Maintenance: Plain Balloon Angioplasty.
Plain balloon angioplasty remains the first-line treatment for dialysis access stenosis. This chapter reviews the outcomes of plain balloon angioplasty from cohort studies and comparative studies. Angioplasty outcomes are more favourable in arteriovenous fistulae (AVF) compared to arteriovenous grafts (AVG) with primary patency at 6Â months ranging from 42-63% compared to 27-61%, respectively, and improved for forearm fistulae compared with upper arm fistulae. Higher pressures are required to treat stenoses in AVFs compared to AVGs. Outcomes are worse in more severe stenoses, increased patient age, previous interventions and fistulae that develop early stenoses. Major complication rates following angioplasty in dialysis access are between 3 and 5%. Repeat treatments and the use of adjuncts such as drug-coated balloons and stents can prolong the patency of dialysis access. Level of Evidence No level of evidence (Review paper)
D-DEMOS: A Distributed, End-to-End Verifiable, Internet Voting System
E-voting systems have emerged as a powerful technology for improving
democracy by reducing election cost, increasing voter participation, and even
allowing voters to directly verify the entire election procedure. Prior
internet voting systems have single points of failure, which may result in the
compromise of availability, voter secrecy, or integrity of the election
results. In this paper, we present the design, implementation, security
analysis, and evaluation of D-DEMOS, a complete e-voting system that is
distributed, privacy-preserving and end-to-end verifiable. Our system includes
a fully asynchronous vote collection subsystem that provides immediate
assurance to the voter her vote was recorded as cast, without requiring
cryptographic operations on behalf of the voter. We also include a distributed,
replicated and fault-tolerant Bulletin Board component, that stores all
necessary election-related information, and allows any party to read and verify
the complete election process. Finally, we also incorporate trustees, i.e.,
individuals who control election result production while guaranteeing privacy
and end-to-end-verifiability as long as their strong majority is honest. Our
system is the first e-voting system whose voting operation is human verifiable,
i.e., a voter can vote over the web, even when her web client stack is
potentially unsafe, without sacrificing her privacy, and still be assured her
vote was recorded as cast. Additionally, a voter can outsource election
auditing to third parties, still without sacrificing privacy. Finally, as the
number of auditors increases, the probability of election fraud going
undetected is diminished exponentially. We provide a model and security
analysis of the system. We implement a prototype of the complete system, we
measure its performance experimentally, and we demonstrate its ability to
handle large-scale elections.Comment: 17 pages, 5 figure
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Transcatheter arterialization of the deep veins: 1-year outcomes of PROMISE-UK study
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