Four generated, squarefree, monomial ideals

Let $I\supsetneq J$ be two squarefree monomial ideals of a polynomial algebra over a field generated in degree $\geq d$, resp. $\geq d+1$ . Suppose that $I$ is either generated by three monomials of degrees $d$ and a set of monomials of degrees $\geq d+1$, or by four special monomials of degrees $d$. If the Stanley depth of $I/J$ is $\leq d+1$ then the usual depth of $I/J$ is $\leq d+1$ too.Comment: to appear in "Bridging Algebra, Geometry, and Topology", Editors Denis Ibadula, Willem Veys, Springer Proceed. in Math. and Statistics, 96, 201

Beyond Problems and Cases: Discussion Materials for Accounting in Executive Programs Business School

Selection or development of classroom materials for an accounting class in an executive program is complicated by the fact that some students enter the program with a substantial knowledge of accounting while others may have no background at all. Furthermore, general management programs do not usually focus on making all students equally knowledgeable about what accountants do and how to use the information that accounting provides. Problems and cases are sometimes not successful as discussion materials in the mixed audience class because some students are not challenged while others are overwhelmed because of their lack of exposure to the methods and principles of accounting. We describe a new class of materials prepared for executive program accounting classes that are based on contemporary events that become the bases for informed discussion among students where learning takes place at each student’s level while working in small groups to understand the problems, possible solutions, and actions that might be taken to clarify issues and solutions to the problems posed. Three examples are described and illustrated

Getting healthier : creating interactive cooking tools for kids

Cooking lessons are believed to be the basis for a healthy lifestyle for both children and adults. However, while children learn their eating habits during childhood, most people only learn to cook from the age of sixteen onwards. Therefore, it is suggested that people should learn to cook during childhood. Current cooking classes aim mainly at the cognitive skills, with children learning about food in a traditional setting, i.e. in class and from books. Children are taught that water boils at a hundred degrees Celsius by using numbers and visualizations of thermometers, instead of what boiling water looks like. This way of teaching contrasts very much with the rich sensorial experience that cooking actually is. Therefore, we argue that learning about cooking should be aimed more at exploiting the perceptual-emotional skills. In the current paper we present the design and development of an interactive learning environment that teaches children how to prepare healthy meals. The project was developed by means of a process referred to as research through design, i.e. by iteratively ideating concepts, making prototypes and evaluating them in context. A key element of this project is the facilitation of learning by doing in the interactive learning environment. It is argued that performing an action is a more effective way of learning than learning on a cognitive level. In addition, principles from tangible interaction have been integrated in the design. Tangible interfaces are believed to engage multiple senses, support natural learning and create playfulness. The Supersous Game supports an interactive feedback loop with five different cooking tools; a knife, a peeler, a masher, a scale and a rasp. The game guides the children through the process of cooking by auditory guides and visual explanations. Various prototype iterations have been evaluated on interaction and experience at an after school day care centre with children in the age group of 7 to 11 years. The experiential results, which were obtained by means of semi-structured interviews, suggest that after playing the game the children have a more positive attitude towards cooking. In addition, children have greater confidence in their ability to cook and have a better understanding of how they can eat healthier. Furthermore, all children indicated that they wanted to play the game more often, and some even mentioned that they would like to involve their parents in the process of cooking as well. Moreover, parents were surprised by the cooking skills of their children, as well as of their willingness to try out new self-prepared dishes. Finally, the evaluation of the interaction suggests possible improvements to the environment such as applying inherent feedback and personalization of guidance. The presented project suggests that interactive games may support a healthier lifestyle for children and that interactive learning environments could offer new opportunities for health promotion programs

Access-Control Policies via Belnap Logic: Effective and Efficient Composition and Analysis

It is difficult to develop and manage large, multi-author access control policies without a means to compose larger policies from smaller ones. Ideally, an access-control policy language will have a small set of simple policy combinators that allow for all desired policy compositions. In [5], a policy language was presented having policy combinators based on Belnap logic, a four-valued logic in which truth values correspond to policy results of grant , deny , conflict , and undefined . We show here how policies in this language can be analyzed, and study the expressiveness of the language. To support policy analysis, we define a query language in which policy analysis questions can be phrased. Queries can be translated into a fragment of first-order logic for which satisfiability and validity checks are computable by SAT solvers or BDDs. We show how policy analysis can then be carried out through model checking, validity checking, and assume-guarantee reasoning over such translated queries. We also present static analysis methods for the particular questions of whether policies contain gaps or conflicts. Finally, we establish expressiveness results showing that all data independent policies can be expressed in our policy language. © 2008 IEEE

Gauge invariance in two-particle scattering

It is shown how gauge invariance is obtained for the coupling of a photon to a two-body state described by the solution of the Bethe-Salpeter equation. This is illustrated both for a complex scalar field theory and for interaction kernels derived from chiral effective Lagrangians.Comment: 16 pages, 2 figures, references added and commented o

Transforming the complexity of a theoretical framework into an experiental design methodology for designers

In design, a wide range of design tools and techniques that are derived from theoretical frameworks have been developed. However, there are only a few that consider the perceptual qualities involved in interaction. Although existing tools are widely adopted, designer’s need for considering theoretical notions of ecological perception (Gibson, 1986), embodied interaction (Dourish, 2011) and affordances (Gibson, 1986; Norman, 1988; Hartson, 2003) has not been addressed in the context of design tools. This paper describes the development of an experiential design method card system based on the Interaction Frogger framework (Wensveen, 2004). The design method card supports designers to better understand the perceptual qualities of interaction design and convey this knowledge into their design processes. First, we introduce various theoretical frameworks that deal with perceptual qualities within interaction design, particularly focusing on the Interaction Frogger framework. Consequently, we investigate how a complex theoretical framework can be translated into practice utilising a design tool, by examining a case study of developing a set of design method cards. This set of method cards was examined by means of focus group sessions with design researchers and redesign exercises with designers and design students from various backgrounds. Throughout the redesign exercise, the experiential nature of the method cards system helped designers and design students to gain insights into perceptual information exchanges that emerge between objects and users. Furthermore, the method cards gave them a systematic platform for these insights to be reapplied into their design process. Overall, the design method card system provides opportunities for design practitioners, researchers, and students to explore perceptual qualities within the interaction design space and further an opportunity to utilize theoretical knowledge in a practical design process

Access control via belnap logic: intuitive, expressive, and analyzable policy composition

Access control to IT systems increasingly relies on the ability to compose policies. There is thus bene t in any framework for policy composition that is intuitive, formal (and so \an- alyzable" and \implementable"), expressive, independent of speci c application domains, and yet able to be extended to create domain-speci c instances. Here we develop such a framework based on Belnap logic. An access-control policy is interpreted as a four-valued predicate that maps access requests to either grant, deny, con ict, or unspeci ed { the four values of the Bel- nap bilattice. We de ne an expressive access-control policy language PBel, having composition operators based on the operators of Belnap logic. Natural orderings on policies are obtained by lifting the truth and information orderings of the Belnap bilattice. These orderings lead to a query language in which policy analyses, e.g. con ict freedom, can be speci ed. Policy analysis is supported through a reduction of the validity of policy queries to the validity of propositional formulas on predicates over access requests. We evaluate our approach through rewall policy and RBAC policy examples, and discuss domain-speci c and generic extensions of our policy language