From temperament to character

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Opacity with Orwellian Observers and Intransitive Non-interference

Opacity is a general behavioural security scheme flexible enough to account for several specific properties. Some secret set of behaviors of a system is opaque if a passive attacker can never tell whether the observed behavior is a secret one or not. Instead of considering the case of static observability where the set of observable events is fixed off line or dynamic observability where the set of observable events changes over time depending on the history of the trace, we consider Orwellian partial observability where unobservable events are not revealed unless a downgrading event occurs in the future of the trace. We show how to verify that some regular secret is opaque for a regular language L w.r.t. an Orwellian projection while it has been proved undecidable even for a regular language L w.r.t. a general Orwellian observation function. We finally illustrate relevancy of our results by proving the equivalence between the opacity property of regular secrets w.r.t. Orwellian projection and the intransitive non-interference property

Verification of Information Flow Properties under Rational Observation

Information flow properties express the capability for an agent to infer information about secret behaviours of a partially observable system. In a language-theoretic setting, where the system behaviour is described by a language, we define the class of rational information flow properties (RIFP), where observers are modeled by finite transducers, acting on languages in a given family $\mathcal{L}$. This leads to a general decidability criterion for the verification problem of RIFPs on $\mathcal{L}$, implying PSPACE-completeness for this problem on regular languages. We show that most trace-based information flow properties studied up to now are RIFPs, including those related to selective declassification and conditional anonymity. As a consequence, we retrieve several existing decidability results that were obtained by ad-hoc proofs.Comment: 19 pages, 7 figures, version extended from AVOCS'201

Self-similarity and coarsening of three dimensional particles on a one or two dimensional matrix

We examine the validity of the hypothesis of self-similarity in systems coarsening under the driving force of interface energy reduction in which three dimensional particles are intersected by a one or two dimensional diffusion matrix. In both cases, solute fluxes onto the surface of the particles, assumed spherical, depend on both particle radius and inter-particle distance. We argue that overall mass conservation requires independent scalings for particle sizes and inter-particle distances under magnification of the structure, and predict power law growth for the average particle size in the case of a one dimensional matrix (3D/1D), and a weak breakdown of self-similarity in the two dimensional case (3D/2D). Numerical calculations confirm our predictions regarding self-similarity and power law growth of average particle size with an exponent 1/7 for the 3D/1D case, and provide evidence for the existence of logarithmic factors in the laws of boundary motion for the 3D/2D case. The latter indicate a weak breakdown of self-similarity.Comment: RevTeX, 31 pages, 9 figure

Positive Points of Bernie\u27s Green New Deal

The Green New Deal will help will create jobs in the energy market. Many people fear that the workers in the coal mines or oil plants will be out of job but this is actually false. The Green New Deal will create jobs in the energy market, all while switching our infrastructure to 100% renewable energy. The Green New Deal is the best way for our country to become more sustainable, modernize our energy infrastructure, and do it without costing americans jobs. First off the Green New Deal will create 20 million new job openings according to Bernie Sanders campaign website. The Green New Deal plans to create enough jobs to not only cover all the fossil fuels workers but also have enough for new workers. Jobs in the renewable energy field also require more people than fossil fuels. According to the Energy Research Center, it takes twice as many humans to run renewable energy than it does for fossil fuels. On top of that, renewables offer a much safer environment than working in the fossil fuel industries. Coal miners that put their health on the line could be working in hydro power plants that require twice as many human positions and less health risks than the mines. The 2017 Energy and Employment report found that there was a sharp decrease in coal energy jobs since 2009, 57% decrease, while wind energy jobs increased by 37% in just two years from 2015 to 2017. This means is that in just a few years renewable energies are already on their way to being huge job creators. According to the 2017 US Energy and Jobs Report, there are approximately 86,000 coal extraction jobs, 12,000 oil extraction jobs, and 393,000 natural gas extraction jobs in the United States. Moving these workers to a safer renewable energy job will in total help almost half a million people live healthier lives. Historically, mass projects like this have been extremely successful. One obvious example would be the New Deal. The new deal introduced dozens of new social programs as well as work programs and reforms in our financial system. This was a massive project that to combat the effects of the Great Depression and it tested the resolve of every American. What the New Deal and Green New Deal have in common is the fact that it will take massive spending and investment. However, the costs tend to pay for themselves over time, usually at least a couple decades. But the New Deal is not the only point in history that took mass mobilization and cooperation. What many people tend to forget is that it created tons of new jobs. The Green New Deal creating 20 million jobs is no different, it creates plenty of new spots. On top of that, fossil fuel workers are guaranteed 5 years of their previous salary, assistance with housing, job training, health care, and retirement support according to Burnie Sanders campaign website. Moving to completely renewable energy is bold but it would finally modernize our system. For instance, France gets 76% of its energy from nuclear power according to the EIA. This is especially impressive because France is the second largest energy consumer per capita. Germany is already utilizing 31% of its total energy production from renewables and 15% from nuclear power in 2015. These two modern countries dwarf the United States. In 2018 the United States only 17% of our total energy came from renewable energy. It is blatantly obvious that it will take drastic measures of the Green New Deal to modernize our energy systems. While the Green New Deal is extremely drastic, it is necessary. History has shown that movements where incredible spending is necessary can work. On top of that, far more jobs will be created along with multiple benefits to fossil fuel workers. The Green New Deal will allow us to catch up to modern renewable energy producers like France and Germany. Most importantly, it will allow us to combat climate change

Social Media and it\u27s Effects on Mental Health of High School Students

Previous studies have established a link between mental health and social media usage. That research has shown that social media usage in students can be detrimental to their self-esteem, motivation, and generalized anxiety. This study focused on the effects of social media usage on high school students. The hypothesis was that high social media usage would be associated with student mental health. This study included surveying high school students in the Northwest Indiana area. These surveys asked questions regarding how often the students used social media, what they used it for, and what their perceived stress and anxiety levels were regarding social media usage. This study is important because it brings awareness to the community on how social media can have an impact. The presenters include senior Social Work majors Nancy Engel, Kimberly Mullins, and Emma Brandy. The sponsor of this research is Professor Dr. Matthew Ringenberg, the Valparaiso University Social Work Department Chair

Long fluid filled bags suspended by line forces

A previous analysis of fluid filled storage bags is extended to the case of a long fluid filled cylindrical membrane supported by uniform line loads. Cross-sectional shape, stiffness of the support system and stress resultants in the membrane are determined. The application of the numerical results to problems arising in the design of nonrigid airships is discussed