13,949 research outputs found
Towards A Generic, Service-Oriented Framework for Distributed Real-Time Systems
REACTION 2012. 1st International workshop on Real-time and distributed computing in emerging applications. December 4th, 2012, San Juan, Puerto Rico.Continuously increasing complexity and scale of
distributed real-time systems have exposed the limitations of
their existing development methodologies. This fact is evident
by the unsustainable rate of increase in the development and
maintenance costs of such systems. In this paper, we present a
generic, service-oriented framework for distributed real-time
systems. The proposed framework can potentially serve as the
basis for a widely applicable, cross-domain toolset, thus,
decreasing the development and maintenance costs for
distributed real-time systems. The proposed framework
consists of a generic, service-oriented deployment platform
that abstracts away the details of implementation platform and
an associated development methodology. The proposed
framework makes extensive use of the existing service-oriented
technologies such as Web Services. However, it also extends
these technologies for application to distributed real-time
systems by introducing QoS-aware service deployment and
service monitoring phases. This paper presents the details of
the proposed framework as well as a case-study of the
application of the proposed framework to the domain of smart
gri
Using Nyquist or Nyquist-Like Plot to Predict Three Typical Instabilities in DC-DC Converters
By transforming an exact stability condition, a new Nyquist-like plot is
proposed to predict occurrences of three typical instabilities in DC-DC
converters. The three instabilities are saddle-node bifurcation (coexistence of
multiple solutions), period-doubling bifurcation (subharmonic oscillation), and
Neimark bifurcation (quasi-periodic oscillation). In a single plot, it
accurately predicts whether an instability occurs and what type the instability
is. The plot is equivalent to the Nyquist plot, and it is a useful design tool
to avoid these instabilities. Nine examples are used to illustrate the accuracy
of this new plot to predict instabilities in the buck or boost converter with
fixed or variable switching frequency.Comment: Submitted to an IEEE journal in 201
Comparison of Intravitreal Bevacizumab versus Triamcinolone for the Treatment of Diffuse Diabetic Macular Edema
Background: Our purpose was to compare the effect of triamcinolone and bevacizumab (Avastin) on the retinal thickness and functional outcome in patients with diabetic macular edema. Methods and Materials: A collective of 32 patients, who had been treated by a single 4.0-mg intravitreal triamcinolone injection (group 1), was matched to 32 patients ('matched pairs'), who had received 3 injections of 1.25 mg of bevacizumab within 3 months in 4-week intervals (group 2). The outcome variables were changes in best corrected visual acuity (VA) and central retinal thickness 3 months after therapy. Results: Both groups did not differ regarding preoperative VA and central retinal thickness measured by optical coherence tomography. The baseline mean VA was 0.72 +/- 0.39 logMAR in group 1 and 0.73 +/- 0.39 logMAR in group 2 (p = 0.709). The mean central retinal thickness measured by optical coherence tomography was 548 +/- 185 mu m in group 1 and 507 +/- 192 mu m in group 2. While the patients in group 1 experienced a slight increase in VA of on average 0.7 lines following a single triamcinolone injection to a mean of 0.64 +/- 0.40 logMAR (p = 0.066) after 3 months, the patients in group 2 showed almost no effect on VA with an average increase of 0.2 lines to a mean VA of 0.72 +/- 0.30 logMAR (p = 0.948) following 3 intravitreal injections of bevacizumab. Comparing the effect on VA between both groups no statistically significant difference (p = 0.115) was noted. Concerning decrease in central retinal thickness both therapies were highly effective (p < 0.001 each), again, without statistically significant difference between the groups (p < 0.128). Conclusion: Our data suggest that a single triamcinolone injection may be as effective as a 3 times repeated intravitreal administration of bevacizumab for the treatment of diabetic macular edema. Further prospective trials should be performed. Copyright (C) 2010 S. Karger AG, Base
FLICK: developing and running application-specific network services
Data centre networks are increasingly programmable, with application-specific network services proliferating, from custom load-balancers to middleboxes providing caching and aggregation. Developers must currently implement these services using traditional low-level APIs, which neither support natural operations on application data nor provide efficient performance isolation. We describe FLICK, a framework for the programming and execution of application-specific network services on multi-core CPUs. Developers write network services in the FLICK language, which offers high-level processing constructs and application-relevant data types. FLICK programs are translated automatically to efficient, parallel task graphs, implemented in C++ on top of a user-space TCP stack. Task graphs have bounded resource usage at runtime, which means that the graphs of multiple services can execute concurrently without interference using cooperative scheduling. We evaluate FLICK with several services (an HTTP load-balancer, a Memcached router and a Hadoop data aggregator), showing that it achieves good performance while reducing development effort
3+1 dimensional Yang-Mills theory as a local theory of evolution of metrics on 3 manifolds
An explicit canonical transformation is constructed to relate the physical
subspace of Yang-Mills theory to the phase space of the ADM variables of
general relativity. This maps 3+1 dimensional Yang-Mills theory to local
evolution of metrics on 3 manifolds.Comment: 7 pages, revte
A reduced-reference perceptual image and video quality metric based on edge preservation
In image and video compression and transmission, it is important to rely on an objective image/video quality metric which accurately represents the subjective quality of processed images and video sequences. In some scenarios, it is also important to evaluate the quality of the received video sequence with minimal reference to the transmitted one. For instance, for quality improvement of video transmission through closed-loop optimisation, the video quality measure can be evaluated at the receiver and provided as feedback information to the system controller. The original image/video sequence-prior to compression and transmission-is not usually available at the receiver side, and it is important to rely at the receiver side on an objective video quality metric that does not need reference or needs minimal reference to the original video sequence. The observation that the human eye is very sensitive to edge and contour information of an image underpins the proposal of our reduced reference (RR) quality metric, which compares edge information between the distorted and the original image. Results highlight that the metric correlates well with subjective observations, also in comparison with commonly used full-reference metrics and with a state-of-the-art RR metric. © 2012 Martini et al
Effect of pulsed delivery and bouillon base on saltiness and bitterness perceptions of salt delivery profiles partially substituted with KCl
Reducing salt levels in processed food is an important target for a growing numbers of food manufacturers. The effects of pulsed delivery (Dynataste) and bouillon base on saltiness and bitterness perception of partially substituted solutions (KCl) were investigated. Pulsed delivery did not enhance salt perception and resulted in greater Overall Bitterness Scores for the same level of substitution with KCl. The presence of the bouillon base masked to a certain extent the loss of saltiness induced by the substitution and resulted in lower Overall Bitterness Scores of the substituted profiles
Mechanochemical preparation of advanced catalytically active bifunctional Pd containing nanomaterials for aqueous phase hydrogenations
Silicon-Organic Hybrid (SOH) and Plasmonic-Organic Hybrid (POH) integration
Silicon photonics offers tremendous potential for inexpensive high-yield photonic-electronic integration. Besides conventional dielectric waveguides, plasmonic structures can also be efficiently realized on the silicon photonic platform, reducing device footprint by more than an order of magnitude. However, nei-ther silicon nor metals exhibit appreciable second-order optical nonlinearities, thereby making efficient electro-optic modulators challenging to realize. These deficiencies can be overcome by the concepts of silicon-organic hybrid (SOH) and plasmonic-organic hybrid integration, which combine SOI waveguides and plasmonic nanostructures with organic electro-optic cladding materials
Challenges and Opportunities: What Can We Learn from Patients Living with Chronic Musculoskeletal Conditions, Health Professionals and Carers about the Concept of Health Literacy Using Qualitative Methods of Inquiry?
The field of health literacy continues to evolve and concern public health researchers and yet remains a largely overlooked concept elsewhere in the healthcare system. We conducted focus group discussions in England UK, about the concept of health literacy with older patients with chronic musculoskeletal conditions (mean age = 73.4 years), carers and health professionals. Our research posed methodological, intellectual and practical challenges. Gaps in conceptualisation and expectations were revealed, reiterating deficiencies in predominant models for understanding health literacy and methodological shortcomings of using focus groups in qualitative research for this topic. Building on this unique insight into what the concept of health literacy meant to participants, we present analysis of our findings on factors perceived to foster and inhibit health literacy and on the issue of responsibility in health literacy. Patients saw health literacy as a result of an inconsistent interactive process and the implications as wide ranging; healthcare professionals had more heterogeneous views. All focus group discussants agreed that health literacy most benefited from good inter-personal communication and partnership. By proposing a needs-based approach to health literacy we offer an alternative way of conceptualising health literacy to help improve the health of older people with chronic conditions
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