11,563 research outputs found

    An approach to integrating and creating flexible software environments

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    Engineers and scientists are attempting to represent, analyze, and reason about increasingly complex systems. Many researchers have been developing new ways of creating increasingly open environments. In this research on VEHICLES, a conceptual design environment for space systems, an approach was developed, called 'wrapping', to flexibility and integration based on the collection and then processing of explicit qualitative descriptions of all the software resources in the environment. Currently, a simulation is available, VSIM, used to study both the types of wrapping descriptions and the processes necessary to use the metaknowledge to combine, select, adapt, and explain some of the software resources used in VEHICLES. What was learned about the types of knowledge necessary for the wrapping approach is described along with the implications of wrapping for several key software engineering issues

    A comparison of three interactive television AD formats

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    This study explores the effects of interacting with three current interactive television (iTV) ad formats, using an Australian audience panel. Interaction with iTV ads has positive effects on awareness and net positive thoughts, which increase purchase intentions compared with the influence of regular ads. The telescopic format represents the best format, likely because it makes the most of the entertaining possibilities of iTV by offering additional long-form video; its superior performance cannot be explained readily by self-selection effects. The results suggest that the effectiveness of iTV ads should be measured by their interaction rate rather than the much smaller response rate, and iTV advertisers should consider ways to maximize interaction and response rates

    Country differences in technology experience: The effect of teletext on iTV adoption in the United Kingdom

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    This study found that participant’s previous teletext experience and previous iTV experience influenced their openness towards using interactive television in planning independent longhaul holidays. The study surveyed participants for their previous interactive media experience (internet, iTV and teletext) before viewing a linear or interactive television destination promotion. Two ad models (impulse and telescopic) were tested from two program formats (travel program segment and ad break in a lifestyle program). These were aired on a video-on-demand network in London (UK) with 164 people out of a total of 375 participating all the way to the final steps of the study. Participants were most experienced with the Internet (mean 6.29 on 1-7scale) and 50% had had experience with an interactive television provider other than the VOD network. 70% had experience with teletext. Overall, participants felt positively towards interactive television as an information source for holiday planning. Those with teletext experience or iTV experience were more open to iTV than those without such experience. Furthermore, actual interaction with the treatment seemed to moderate the previous experience – iTV attractiveness link. This demonstrated that although previous technology experiences can transfer to new media, the actual experience of using the new media is also a powerful factor

    The demise of a model? The state of collective bargaining and worker representation in Germany.

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    This article investigates collective bargaining trends in the German private sector since 2000. Using data from the IAB Establishment Panel and the German Establishment History Panel, it provides both cross-sectional and longitudinal evidence on these developments. It confirms that the hemorrhaging of sectoral bargaining, first observed in the 1980s and 1990s, is ongoing. Furthermore, works councils are also in decline, so that the dual system also displays erosion. For their part, any increases in collective bargaining at firm level have been minimal in recent years, while the behavior of newly-founded and closing establishments does not seem to lie at the root of a burgeoning collective bargaining free sector. Although there are few obvious signs of an organic reversal of the process, some revitalization of the bargaining system from above is implied by the labor policies of the new coalition government

    Decision-making in a fuzzy environment

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    Decision making where goals or constraints are not sharply defined boundaries and fuzzy using dynamic programmin

    Optimal Timing in Dynamic and Robust Attacker Engagement During Advanced Persistent Threats

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    Advanced persistent threats (APTs) are stealthy attacks which make use of social engineering and deception to give adversaries insider access to networked systems. Against APTs, active defense technologies aim to create and exploit information asymmetry for defenders. In this paper, we study a scenario in which a powerful defender uses honeynets for active defense in order to observe an attacker who has penetrated the network. Rather than immediately eject the attacker, the defender may elect to gather information. We introduce an undiscounted, infinite-horizon Markov decision process on a continuous state space in order to model the defender's problem. We find a threshold of information that the defender should gather about the attacker before ejecting him. Then we study the robustness of this policy using a Stackelberg game. Finally, we simulate the policy for a conceptual network. Our results provide a quantitative foundation for studying optimal timing for attacker engagement in network defense.Comment: Submitted to the 2019 Intl. Symp. Modeling and Optimization in Mobile, Ad Hoc, and Wireless Nets. (WiOpt

    Tracking Control for FES-Cycling based on Force Direction Efficiency with Antagonistic Bi-Articular Muscles

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    A functional electrical stimulation (FES)-based tracking controller is developed to enable cycling based on a strategy to yield force direction efficiency by exploiting antagonistic bi-articular muscles. Given the input redundancy naturally occurring among multiple muscle groups, the force direction at the pedal is explicitly determined as a means to improve the efficiency of cycling. A model of a stationary cycle and rider is developed as a closed-chain mechanism. A strategy is then developed to switch between muscle groups for improved efficiency based on the force direction of each muscle group. Stability of the developed controller is analyzed through Lyapunov-based methods.Comment: 8 pages, 4 figures, submitted to ACC201

    Estimation of internal source distributions using external field measurements in radiative transfer

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    Intensity of emergent radiation for finite homogeneous slab which absorbs radiation and scatters it isotropicall

    Stationary Cycling Induced by Switched Functional Electrical Stimulation Control

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    Functional electrical stimulation (FES) is used to activate the dysfunctional lower limb muscles of individuals with neuromuscular disorders to produce cycling as a means of exercise and rehabilitation. However, FES-cycling is still metabolically inefficient and yields low power output at the cycle crank compared to able-bodied cycling. Previous literature suggests that these problems are symptomatic of poor muscle control and non-physiological muscle fiber recruitment. The latter is a known problem with FES in general, and the former motivates investigation of better control methods for FES-cycling.In this paper, a stimulation pattern for quadriceps femoris-only FES-cycling is derived based on the effectiveness of knee joint torque in producing forward pedaling. In addition, a switched sliding-mode controller is designed for the uncertain, nonlinear cycle-rider system with autonomous state-dependent switching. The switched controller yields ultimately bounded tracking of a desired trajectory in the presence of an unknown, time-varying, bounded disturbance, provided a reverse dwell-time condition is satisfied by appropriate choice of the control gains and a sufficient desired cadence. Stability is derived through Lyapunov methods for switched systems, and experimental results demonstrate the performance of the switched control system under typical cycling conditions.Comment: 8 pages, 3 figures, submitted to ACC 201

    Reducing multi-dimensional information into a 1-d histogram

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    We present two methods for reducing multidimensional information to one dimension for ease of understand or analysis while maintaining statistical power. While not new, dimensional reduction is not greatly used in high-energy physics and has applications whenever there is a distinctive feature (for instance, a mass peak) in one variable but when signal purity depends on others; so in practice in most of the areas of physics analysis. While both methods presented here assume knowledge of the background, they differ in the fact that only one of the methods uses a model for the signal, trading some increase in statistical power for this model dependence
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