79,016 research outputs found
Towards a Layered Architectural View for Security Analysis in SCADA Systems
Supervisory Control and Data Acquisition (SCADA) systems support and control
the operation of many critical infrastructures that our society depend on, such
as power grids. Since SCADA systems become a target for cyber attacks and the
potential impact of a successful attack could lead to disastrous consequences
in the physical world, ensuring the security of these systems is of vital
importance. A fundamental prerequisite to securing a SCADA system is a clear
understanding and a consistent view of its architecture. However, because of
the complexity and scale of SCADA systems, this is challenging to acquire. In
this paper, we propose a layered architectural view for SCADA systems, which
aims at building a common ground among stakeholders and supporting the
implementation of security analysis. In order to manage the complexity and
scale, we define four interrelated architectural layers, and uses the concept
of viewpoints to focus on a subset of the system. We indicate the applicability
of our approach in the context of SCADA system security analysis.Comment: 7 pages, 4 figure
War of the Worlds Revisited: The Effect of Watching The Day After on Mood State
In the fall of 1983, The Day After, a fictional account of a nuclear attack on a civilian population, was broadcast on television in the United States and viewed by I00 million Americans . The Day After was said to differ from previous movie treatments of nuclear war by the vividness with which it forced its audience to experience the ground zero effects of a nuclear blast on human beings (I) . In what was described as the most horrifically searing footage ever to pass a network censor, the audience was shown group immolation, a carnage of mass vaporization and graphic images of death (I). It was widely predicted that this movie would have stressful psychological effects because it dealt with a potentially real disaster. Warnings of possible psychiatric side effects of the film were issued by the American Psychiatric Association , the American Academy of Child Psychiatry, the American Academy of Pediatrics, and the American Broadcasting Company (1,2,3). So seriously were these warnings taken that the Federal Emergency Management Agency increased its staffing in anticipation of the movie\u27s psychological fallout (2). After the movie was shown, however, there was little systematic documentation of its psychological effects on the public. Since similarly graphic movies addressing the effects of nuclear war continue to be released and a replanned for the future, we feel the issue of the psychological effects of these films remains salient
CoCoA: A General Framework for Communication-Efficient Distributed Optimization
The scale of modern datasets necessitates the development of efficient
distributed optimization methods for machine learning. We present a
general-purpose framework for distributed computing environments, CoCoA, that
has an efficient communication scheme and is applicable to a wide variety of
problems in machine learning and signal processing. We extend the framework to
cover general non-strongly-convex regularizers, including L1-regularized
problems like lasso, sparse logistic regression, and elastic net
regularization, and show how earlier work can be derived as a special case. We
provide convergence guarantees for the class of convex regularized loss
minimization objectives, leveraging a novel approach in handling
non-strongly-convex regularizers and non-smooth loss functions. The resulting
framework has markedly improved performance over state-of-the-art methods, as
we illustrate with an extensive set of experiments on real distributed
datasets
Motivating the Generations: Implications for the Higher Education Workplace
Motivated employees are an organization’s most valuable asset. Motivation boosts better performance and productivity on the part of workers, so determining the best ways to encourage employee motivation is significant. This thesis examines the ranked importance of motivational factors of salaried/professional and hourly/classified, full-time employees at the University of Southern Maine
Human Arm simulation for interactive constrained environment design
During the conceptual and prototype design stage of an industrial product, it
is crucial to take assembly/disassembly and maintenance operations in advance.
A well-designed system should enable relatively easy access of operating
manipulators in the constrained environment and reduce musculoskeletal disorder
risks for those manual handling operations. Trajectory planning comes up as an
important issue for those assembly and maintenance operations under a
constrained environment, since it determines the accessibility and the other
ergonomics issues, such as muscle effort and its related fatigue. In this
paper, a customer-oriented interactive approach is proposed to partially solve
ergonomic related issues encountered during the design stage under a
constrained system for the operator's convenience. Based on a single objective
optimization method, trajectory planning for different operators could be
generated automatically. Meanwhile, a motion capture based method assists the
operator to guide the trajectory planning interactively when either a local
minimum is encountered within the single objective optimization or the operator
prefers guiding the virtual human manually. Besides that, a physical engine is
integrated into this approach to provide physically realistic simulation in
real time manner, so that collision free path and related dynamic information
could be computed to determine further muscle fatigue and accessibility of a
product designComment: International Journal on Interactive Design and Manufacturing
(IJIDeM) (2012) 1-12. arXiv admin note: substantial text overlap with
arXiv:1012.432
The medical management of cerebral palsy
Medical management of cerebral palsy is a complex issue that should be undertaken with the overall aim to improve comfort, function in every day life, self confidence, participation and independence. Although the main focus is commonly the motor disorder, medical management also encompasses far wider issues including the management of multiple co-morbidities (e.g. epilepsy, visual and hearing impairment, gastro-oesophageal reflux and constipation, learning and behavioural difficulties) which require close multi-disciplinary teamwork. High muscle tone can be broadly considered as either spasticity, dystonia, or commonly a mixed pattern. Strategies to reduce muscle tone include enteral medication, botulinum neurotoxin, intra-thecal Baclofen, and selective dorsal rhizotomy. However, strength training and reduction of inserted involuntary movements are equally important strategies to improve function. We also discuss treatable conditions which mimic cerebral palsy, and explore potential future therapies such as stem cells
A terahertz polarization insensitive dual band metamaterial absorber
Metamaterial absorbers have attracted considerable attention for applications in the terahertz range. In this Letter, we report the design, fabrication, and characterization of a terahertz dual band metamaterial absorber that shows two distinct absorption peaks with high absorption. By manipulating the periodic patterned structures as well as the dielectric layer thickness of the metal–dielectric–metal structure, significantly high absorption can be obtained at specific resonance frequencies. Finite-difference time-domain modeling is used to design the structure of the absorber. The fabricated devices have been characterized using a Fourier transform IR spectrometer. The experimental results show two distinct absorption peaks at 2.7 and 5.2 THz, which are in good agreement with the simulation. The absorption magnitudes at 2.7 and 5.2 THz are 0.68 and 0.74, respectively
Mutation testing on an object-oriented framework: An experience report
This is the preprint version of the article - Copyright @ 2011 ElsevierContext
The increasing presence of Object-Oriented (OO) programs in industrial systems is progressively drawing the attention of mutation researchers toward this paradigm. However, while the number of research contributions in this topic is plentiful, the number of empirical results is still marginal and mostly provided by researchers rather than practitioners.
Objective
This article reports our experience using mutation testing to measure the effectiveness of an automated test data generator from a user perspective.
Method
In our study, we applied both traditional and class-level mutation operators to FaMa, an open source Java framework currently being used for research and commercial purposes. We also compared and contrasted our results with the data obtained from some motivating faults found in the literature and two real tools for the analysis of feature models, FaMa and SPLOT.
Results
Our results are summarized in a number of lessons learned supporting previous isolated results as well as new findings that hopefully will motivate further research in the field.
Conclusion
We conclude that mutation testing is an effective and affordable technique to measure the effectiveness of test mechanisms in OO systems. We found, however, several practical limitations in current tool support that should be addressed to facilitate the work of testers. We also missed specific techniques and tools to apply mutation testing at the system level.This work has been partially supported by the European Commission (FEDER) and Spanish Government under CICYT Project SETI (TIN2009-07366) and the Andalusian Government Projects ISABEL (TIC-2533) and THEOS (TIC-5906)
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