On the effectiveness of the incremental approach to minimal chordal edge modification

Because edge modification problems are computationally difficult for most target graph classes, considerable attention has been devoted to inclusion-minimal edge modifications, which are usually polynomial-time computable and which can serve as an approximation of minimum cardinality edge modifications, albeit with no guarantee on the cardinality of the resulting modification set. Over the past fifteen years, the primary design approach used for inclusion-minimal edge modification algorithms is based on a specific incremental scheme. Unfortunately, nothing guarantees that the set E of edge modifications of a graph G that can be obtained in this specific way spans all the inclusion-minimal edge modifications of G. Here, we focus on edge modification problems into the class of chordal graphs and we show that for this the set E may not even contain any solution of minimum size and may not even contain a solution close to the minimum; in fact, we show that it may not contain a solution better than within an Ω(n) factor of the minimum. These results show strong limitations on the use of the current favored algorithmic approach to inclusion-minimal edge modification in heuristics for computing a minimum cardinality edge modification. They suggest that further developments might be better using other approaches.publishedVersio

Holistic Cyber Education

This paper provides a multi-level, multidisciplinary approach for holistically integrating cyber into a student’s academic experience. Our approach suggests formally integrating cyber throughout an institution’s curriculum, including within the required general education program, in electives from a variety of disciplines, as multi-course threads, as minors, and in numerous cyber-related majors. Our holistic approach complements in-class curricula with both a pervasive cyber-aware environment and experiential, outside-the-classroom activities that apply concepts and skills in real-world environments. The goal of our approach is to provide all educated individuals a level of cyber education appropriate for their role in society. Throughout the description of our approach, we include examples of its implementation at the United States Military Academy.https://digitalcommons.usmalibrary.org/books/1024/thumbnail.jp

Educating Future Multidisciplinary Cybersecurity Teams

We present a vision and the curricular foundations needed for the multidisciplinary cybersecurity teams of the future, which are made up of diverse cybersecurity experts, each contributing unique abilities and perspectives that emerged from their own discipline-centric methodological approaches. Examples demonstrating the effectiveness of current and emerging multidisciplinary cybersecurity teams are included

Gemini and Lowell observations of 67P/Churyumov−Gerasimenko during the <i>Rosetta</i> mission

We present observations of comet 67P/Churyumov−Gerasimenko acquired in support of the Rosetta mission. We obtained usable data on 68 nights from 2014 September until 2016 May, with data acquired regularly whenever the comet was observable. We collected an extensive set of near-IR J, H and Ks data throughout the apparition plus visible-light images in g', r', i' and z' when the comet was fainter. We also obtained broad-band R and narrow-band CN filter observations when the comet was brightest using telescopes at Lowell Observatory. The appearance was dominated by a central condensation and the tail until 2015 June. From 2015 August onwards, there were clear asymmetries in the coma, which enhancements revealed to be due to the presence of up to three features (i.e. jets). The features were similar in all broad-band filters; CN images did not show these features but were instead broadly enhanced in the southeastern hemisphere. Modelling using the parameters from Vincent et al. replicated the dust morphology reasonably well, indicating that the pole orientation and locations of active areas have been relatively unchanged over at least the last three apparitions. The dust production, as measured by A(0°)fρ peaked ∼30 d after perihelion and was consistent with predictions from previous apparitions. A(0°)fρ as a function of heliocentric distance was well fitted by a power law with slope −4.2 from 35 to 120 d post-perihelion. We detected photometric evidence of apparent outbursts on 2015 August 22 and 2015 September 19, although neither was discernible morphologically in this data set

Quantitative Effects of Iron Chelators on Hydroxyl Radical Production by the Superoxide-Driven Fenton Raction

Iron bound to certain chelators is known to promote the conversion of superoxide radicals (O2) to hydroxyl radicals (HO\u27) by the superoxide-driven Fenton reaction. The production of HO\u27 by various iron chelates was studied using the reaction of dimethyl sulfoxide and HO\u27 to produce methane sulphinic acid. Methane sulphinic acid was quantified by use of a simple colorimetric assay and used to determine the amounts of HO\u27 produced. Superoxide was generated from 200 M hypoxanthine and 0.05 U/ml xanthine oxidase in the presence of 0-100 M iron and 100 M of each chelator. The results of this preliminary investigation illustrate that, at physiological pH, the superoxide-driven Fenton reaction is significantly promoted by iron chelated to EDTA, nitrilotriacetate, and citrate, but is not promoted by the other anions studied

Enhancing Cybersecurity Content in Undergraduate Information Systems Programs: A Way Forward

The ongoing barrage of data and infrastructure breaches is a constant reminder of the critical need to enhance the cybersecurity component of modern undergraduate information systems (IS) education. Although the most recent undergraduate information systems curricular guidelines (IS2010) highlight security in the context of data, enterprise architecture, and risk management, much more needs to be done. The IS education community needs to identify cybersecurity competencies and curricular content that further integrates cybersecurity principles and practices into IS curricular guidelines. Until this is completed at the IS community level, IS programs will need to fulfill this role individually. This paper contributes to both these efforts by reviewing relevant literature and initiatives – highlighting two primary paths of curricular development: (1) the evolution of IS curricular guidelines, and (2) the development of Cybersecurity as a standalone discipline. Using these resources, the paper summarizes best practices for integrating cybersecurity into curricula and explores the integration of IS into cybersecurity programs

Creating a Multifarious Cyber Science Major

Existing approaches to computing-based cyber undergraduate majors typically take one of two forms: a broad exploration of both technical and human aspects, or a deep technical exploration of a single discipline relevant to cybersecurity. This paper describes the creation of a third approach—a multifarious major, consistent with Cybersecurity Curricula 2017, the ABET Cybersecurity Program Criteria, and the National Security Agency Center for Academic Excellence—Cyber Operations criteria. Our novel curriculum relies on a 10-course common foundation extended by one of five possible concentrations, each of which is delivered through a disciplinary lens and specialized into a highly relevant computing interest area serving society’s diverse cyber needs. The journey began years ago when we infused cybersecurity education throughout our programs, seeking to keep offerings and extracurricular activities relevant in society’s increasingly complex relationship with cyberspace. This paper details the overarching design principles, decision-making process, benchmarking, and feedback elicitation activities. A surprising key step was merging several curricula proposals into a single hybrid option. The new major attracted a strong initial cohort, meeting our enrollment goals and exceeding our diversity goals. We provide several recommendations for any institution embarking on a process of designing a new cyber-named major

Mechanical Alloying for Making Thermoelectric Compounds

An economical room-temperature mechanical alloying process has been shown to be an effective means of making a homogeneous powder that can be hot-pressed to synthesize a thermoelectric material having reproducible chemical composition. The synthesis of a given material consists of the room temperature thermomechanical-alloying process followed b y a hot-pressing process. Relative to synthesis of nominally the same material by a traditional process that includes hot melting, this s ynthesis is simpler and yields a material having superior thermoelect ric properties

Stress transmission in granular matter

The transmission of forces through a disordered granular system is studied by means of a geometrical-topological approach that reduces the granular packing into a set of layers. This layered structure constitutes the skeleton through which the force chains set up. Given the granular packing, and the region where the force is applied, such a skeleton is uniquely defined. Within this framework, we write an equation for the transmission of the vertical forces that can be solved recursively layer by layer. We find that a special class of analytical solutions for this equation are L\'evi-stable distributions. We discuss the link between criticality and fragility and we show how the disordered packing naturally induces the formation of force-chains and arches. We point out that critical regimes, with power law distributions, are associated with the roughness of the topological layers. Whereas, fragility is associated with local changes in the force network induced by local granular rearrangements or by changes in the applied force. The results are compared with recent experimental observations in particulate matter and with computer simulations.Comment: 14 pages, Latex, 5 EPS figure