18,120 research outputs found
Beam Loss Monitors at LHC
One of the main functions of the LHC beam loss measurement system is the
protection of equipment against damage caused by impacting particles creating
secondary showers and their energy dissipation in the matter. Reliability
requirements are scaled according to the acceptable consequences and the
frequency of particle impact events on equipment. Increasing reliability often
leads to more complex systems. The downside of complexity is a reduction of
availability; therefore, an optimum has to be found for these conflicting
requirements. A detailed review of selected concepts and solutions for the LHC
system will be given to show approaches used in various parts of the system
from the sensors, signal processing, and software implementations to the
requirements for operation and documentation.Comment: 16 pages, contribution to the 2014 Joint International Accelerator
School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14
Nov 201
State of Alaska Election Security Project Phase 2 Report
A laska’s election system is among the most secure in the country,
and it has a number of safeguards other states are now adopting. But
the technology Alaska uses to record and count votes could be improved—
and the state’s huge size, limited road system, and scattered communities
also create special challenges for insuring the integrity of the vote.
In this second phase of an ongoing study of Alaska’s election
security, we recommend ways of strengthening the system—not only the
technology but also the election procedures. The lieutenant governor
and the Division of Elections asked the University of Alaska Anchorage to
do this evaluation, which began in September 2007.Lieutenant Governor Sean Parnell.
State of Alaska Division of Elections.List of Appendices / Glossary / Study Team / Acknowledgments / Introduction / Summary of Recommendations / Part 1 Defense in Depth / Part 2 Fortification of Systems / Part 3 Confidence in Outcomes / Conclusions / Proposed Statement of Work for Phase 3: Implementation / Reference
Securing Web-Based E-Voting System Using Captcha and SQL Injection Filter
 The electoral system is very necessary in the democratic life of students, especially to elect a senate chairman in a higher education environment. The use of conventional electoral system is slow, inefficient, and insecure compared to that of electronic-based because it requires a long time for the registration to implementation and counting of votes; use a lot of papers; and it raises the potential for manipulation of ballot papers. In this research, we developed a student electoral system that is safe from non-human participants and electronic-based called e-voting. The system was built with a web platform using PHP and MySQL programming applications. The system development method follows the System Life Cycle (SLC) which consists of the stages of planning, analysis, design, implementation, and testing of the system. This system implements a security mechanism in the form of verification using captcha and SQL injection filter and is implemented in the activities of Komisi Pemilihan Umum Mahasiswa (KPUM). System testing to measure the suitability of implementation with the needs was done using a blackbox method. The result of this research is an e-voting system that satisfies the prevention test of SQL injection and non-human participants attack
A privacy-preserving, decentralized and functional Bitcoin e-voting protocol
Bitcoin, as a decentralized digital currency, has caused extensive research
interest. There are many studies based on related protocols on Bitcoin,
Bitcoin-based voting protocols also received attention in related literature.
In this paper, we propose a Bitcoin-based decentralized privacy-preserving
voting mechanism. It is assumed that there are n voters and m candidates. The
candidate who obtains t ballots can get x Bitcoins from each voter, namely nx
Bitcoins in total. We use a shuffling mechanism to protect voter's voting
privacy, at the same time, decentralized threshold signatures were used to
guarantee security and assign voting rights. The protocol can achieve
correctness, decentralization and privacy-preservings. By contrast with other
schemes, our protocol has a smaller number of transactions and can achieve a
more functional voting method.Comment: 5 pages;3 figures;Smartworld 201
Airborne Advanced Reconfigurable Computer System (ARCS)
A digital computer subsystem fault-tolerant concept was defined, and the potential benefits and costs of such a subsystem were assessed when used as the central element of a new transport's flight control system. The derived advanced reconfigurable computer system (ARCS) is a triple-redundant computer subsystem that automatically reconfigures, under multiple fault conditions, from triplex to duplex to simplex operation, with redundancy recovery if the fault condition is transient. The study included criteria development covering factors at the aircraft's operation level that would influence the design of a fault-tolerant system for commercial airline use. A new reliability analysis tool was developed for evaluating redundant, fault-tolerant system availability and survivability; and a stringent digital system software design methodology was used to achieve design/implementation visibility
Design verification of SIFT
A SIFT reliable aircraft control computer system, designed to meet the ultrahigh reliability required for safety critical flight control applications by use of processor replications and voting, was constructed for SRI, and delivered to NASA Langley for evaluation in the AIRLAB. To increase confidence in the reliability projections for SIFT, produced by a Markov reliability model, SRI constructed a formal specification, defining the meaning of reliability in the context of flight control. A further series of specifications defined, in increasing detail, the design of SIFT down to pre- and post-conditions on Pascal code procedures. Mechanically checked mathematical proofs were constructed to demonstrate that the more detailed design specifications for SIFT do indeed imply the formal reliability requirement. An additional specification defined some of the assumptions made about SIFT by the Markov model, and further proofs were constructed to show that these assumptions, as expressed by that specification, did indeed follow from the more detailed design specifications for SIFT. This report provides an outline of the methodology used for this hierarchical specification and proof, and describes the various specifications and proofs performed
Assessment of the NASA Flight Assurance Review Program
The NASA flight assurance review program to develop minimum standard guidelines for flight assurance reviews was assessed. Documents from NASA centers and NASA headquarters to determine current design review practices and procedures were evaluated. Six reviews were identified for the recommended minimum. The practices and procedures used at the different centers to incorporate the most effective ones into the minimum standard review guidelines were analyzed and guidelines for procedures, personnel and responsibilies, review items/data checklist, and feedback and closeout were defined. The six recommended reviews and the minimum standards guidelines developed for flight assurance reviews are presented. Observations and conclusions for further improving the NASA review and quality assurance process are outlined
Development and analysis of the Software Implemented Fault-Tolerance (SIFT) computer
SIFT (Software Implemented Fault Tolerance) is an experimental, fault-tolerant computer system designed to meet the extreme reliability requirements for safety-critical functions in advanced aircraft. Errors are masked by performing a majority voting operation over the results of identical computations, and faulty processors are removed from service by reassigning computations to the nonfaulty processors. This scheme has been implemented in a special architecture using a set of standard Bendix BDX930 processors, augmented by a special asynchronous-broadcast communication interface that provides direct, processor to processor communication among all processors. Fault isolation is accomplished in hardware; all other fault-tolerance functions, together with scheduling and synchronization are implemented exclusively by executive system software. The system reliability is predicted by a Markov model. Mathematical consistency of the system software with respect to the reliability model has been partially verified, using recently developed tools for machine-aided proof of program correctness
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