1,619 research outputs found
Interpolation Properties and SAT-based Model Checking
Craig interpolation is a widespread method in verification, with important
applications such as Predicate Abstraction, CounterExample Guided Abstraction
Refinement and Lazy Abstraction With Interpolants. Most state-of-the-art model
checking techniques based on interpolation require collections of interpolants
to satisfy particular properties, to which we refer as "collectives"; they do
not hold in general for all interpolation systems and have to be established
for each particular system and verification environment. Nevertheless, no
systematic approach exists that correlates the individual interpolation systems
and compares the necessary collectives. This paper proposes a uniform
framework, which encompasses (and generalizes) the most common collectives
exploited in verification. We use it for a systematic study of the collectives
and of the constraints they pose on propositional interpolation systems used in
SAT-based model checking
Virtual Enterprises Risk Management DSS under Electronic Commerce
Risk management is important to the development of enterprise as well as social-economic prosperity. Virtual enterprise is the potential mode of future enterprise under electronic commerce environment and the risk management for it is a popular research area recently. Due to the complexity of its risk management a decision support system (DSS) with 3-bases-1-cell structure was designed. By coordinating data base, model base, algorithm base and dialogue cell, the functions of project management, risk identification, risk assessment, risk evaluation and risk programming was supported. The user-friendly system has such main characteristics as generality for verity virtual enterprise as well as different projects and the flexibility of model and algorithm, ensuring a standardized, scientific and informational risk management for virtual enterprises
A Risk Identification Method of Virtual Enterprise
Virtual enterprise is the potential mode of future enterprise under global economic environment and the risk management for it is a popular research area recently. Risk identification is the key phrase of risk management. Considering the risk identification problem in the virtual enterprise, a new identification method based on the BP network is provided in this paper. Using this method and the data related to the problem, the possible to take place of the risks could be obtained by training the neural network, so that risks can be investigated in time and managed effectively. The simulation results prove its validit
Evolution of Non-Equilibrium Profile in Adsorbate Layer under Compressive Strain
We investigate the time evolution of an initial step profile separating a
bare substrate region from the rest of the compressively strained adsorbate
layer near a commensurate to incommensurate transition. The rate of profile
evolution as a function of the mismatch, coverage and the strength of the
substrate potential are determined by Brownian molecular dynamics simulations.
We find that the results are qualitatively similar to those observed for the
Pb/Si(111) system. The anomalously fast time evolution and sharpness of the
non-equilibrium profile can be understood through the domain wall creation at
the boundary and its subsequent diffusion into the interior of the adsorbate
layer.Comment: 6 pages, 7 figures, Tribology Letter
Search for Invisible Decays of and in and
Using a data sample of decays collected with the BES
II detector at the BEPC, searches for invisible decays of and
in to and are performed.
The signals, which are reconstructed in final states, are used
to tag the and decays. No signals are found for the
invisible decays of either or , and upper limits at the 90%
confidence level are determined to be for the ratio
and for . These are the first
searches for and decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo
Backward pion-nucleon scattering
A global analysis of the world data on differential cross sections and
polarization asymmetries of backward pion-nucleon scattering for invariant
collision energies above 3 GeV is performed in a Regge model. Including the
, , and trajectories, we
reproduce both angular distributions and polarization data for small values of
the Mandelstam variable , in contrast to previous analyses. The model
amplitude is used to obtain evidence for baryon resonances with mass below 3
GeV. Our analysis suggests a resonance with a mass of 2.83 GeV as
member of the trajectory from the corresponding Chew-Frautschi
plot.Comment: 12 pages, 16 figure
Believability of cigarette warnings about addiction: National experiments of adolescents and adults
Introduction: We conducted two experiments to examine the believability of three addictionfocused cigarette warnings and the influence of message source on believability among adolescents and adults in the United States. Methods: Experimental data were collected using national phone surveys of adolescents (age 13-17; n = 1125; response rate, 66%) and adults (age 18+; n = 5014; response rate, 42%). We assessed the believability of three cigarette warnings about addiction attributed to four message sources (Food and Drug Administration [FDA], Surgeon General, Centers for Disease Control and Prevention [CDC], no source). Results: The majority of adolescents and adults reported the three cigarette warnings were very believable (49%-81% for adolescents; 47%-76% for adults). We found four to five times higher odds of adolescents believing a warning that cigarettes are addictive (warning 1) or that nicotine was an addictive chemical (warning 2) compared to a warning that differentiated the addictive risks of menthol versus traditional cigarettes (warning 3), warning 1 adjusted odds ratio (aOR): 4.53, 95% confidence interval (CI): 3.10, 6.63; warning 2 aOR: 3.87, 95% CI: 2.70, 5.50. Similarly, we found three to five times higher odds of adults (including current smokers) believing the same warnings, warning 1 aOR: 3.74, 95% CI: 2.82, 4.95; warning 2 aOR: 3.24, 95% CI: 2.45, 4.28. Message source had no overall impact on the believability of warnings for either population. Conclusions: Our findings support the implementation of FDA's required warnings that cigarettes are addictive and that nicotine is an addictive chemical. These believable warnings may deter adolescents from initiating smoking and encourage adults to quit smoking. Implications: This article describes, for the first time, the believability of different cigarette warnings about addiction. We now know that the majority of adolescents and adults believe cigarette warnings that highlight cigarettes as addictive and that nicotine is an addictive chemical in tobacco. However, a warning that highlighted the relative risk of addiction for menthol cigarettes compared to traditional cigarettes was not as believable among either population. Our findings support the implementation of FDA's required warnings that cigarettes are addictive and that nicotine is an addictive chemical that may deter adolescents from initiating smoking and encourage adults to quit smoking
Creating sustainable value through food waste management: does retail customer value proposition matter?
Purpose
This research aims to explore retail managers' views on how food waste (FW) management activities contribute to sustainable value creation and how the customer value proposition (CVP) for a given food retailer interacts with their approaches to FW management.
Design/methodology/approach
A three-stage exploratory qualitative approach to data collection and analysis was adopted, involving in-depth interviews with retail managers, documentary analysis of multiple years of relevant corporate reports and email validation by seven major UK grocery retailers. Thematic content analysis supplemented by word similarity cluster analysis, two-step cluster analysis and crisp-set qualitative comparative analysis was undertaken.
Findings
FW management practices have been seen by retail managers to contribute to all forms of sustainable value creation, as waste reduction minimises environmental impact, saves costs and/or serves social needs, whilst economic value creation lies at the heart of retail FW management. However, retail operations are also framed by CVP and size of a retailer that enable or inhibit the adoption of certain FW management practices. Low-price retailers were more likely to adopt practices enabling them to save costs. Complicated cost-incurring solutions to FW were more likely to be adopted by retailers associated with larger size, high quality and a range of services.
Originality/value
This study is the first of its kind to empirically explore retail managers' perception of sustainable value creation through FW management activities and to provide empirical evidence of the linkages between retail CVP and sustainable value creation in the context of retail FW management
Observation of Two New N* Peaks in J/psi -> and Decays
The system in decays of is limited to be
isospin 1/2 by isospin conservation. This provides a big advantage in studying
compared with and experiments which mix
isospin 1/2 and 3/2 for the system. Using 58 million decays
collected with the Beijing Electron Positron Collider, more than 100 thousand
events are obtained. Besides two well known
peaks at 1500 MeV and 1670 MeV, there are two new, clear peaks in
the invariant mass spectrum around 1360 MeV and 2030 MeV. They are the
first direct observation of the peak and a long-sought "missing"
peak above 2 GeV in the invariant mass spectrum. A simple
Breit-Wigner fit gives the mass and width for the peak as MeV and MeV, and for the new peak above 2 GeV
as MeV and MeV, respectively
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