Search results for "General Computer Science"
showing 10 items of 895 documents
On Horn spectra
1991
Abstract A Horn spectrum is a spectrum of a Horn sentence. We show that to solve Asser's problem, and consequently the EXPTIME = ? NEXPTIME question it suffices to consider the class of Horn spectra. We also pose the problem whether or not the generator of every Horn spectrum is a spectrum. We prove that from a negative solution of the generator problem, a negative answer for the EXPTIME = ? NEXPTIME question follows. Some other relations between the generator problem and Asser's problem are given. Finally, the relativized version of the generator problem is formulated and it is shown that it has an affirmative solution for some oracles, and a negative solution for some others.
The identity type weak factorisation system
2008
We show that the classifying category C(T) of a dependent type theory T with axioms for identity types admits a non-trivial weak factorisation system. We provide an explicit characterisation of the elements of both the left class and the right class of the weak factorisation system. This characterisation is applied to relate identity types and the homotopy theory of groupoids.
Factors affecting Nigerian teacher educators’ technology integration : Considering characteristics, knowledge constructs, ICT practices and beliefs
2020
To provide a diverse comprehension of teachers' TPACK (Technological, Pedagogical, and Content Knowledge) and how TPACK is reflected in practice, this study examined teacher educators' (TEs') conceptions of technology integration. Specifically, the main objective of the study was to investigate the factors influencing Nigerian teacher educators' technology integration using a self-completion survey administered to Nigerian teacher educators from three schools in the southern region of Nigeria. We utilized the partial least squares structural equation modeling (PLS-SEM) approach for the data analysis. Two frameworks—TPACK and Second Information Technology in Education Study (SITES)— guided t…
Producer's spatial equilibrium with a fuzzy constraint
1980
The classical theory of the producer’s equilibrium rests on two sets of particularly restrictive hypotheses. First it is implicitely assumed that all inputs and outputs are located in a single place where the producer is also implanted and where the production is carried out. Next it is assumed that the producer follows a precise behaviour pattern, by this we mean that the producer has complete information concerning the conditions of hisproductive activity and he has perfect command over both the set of inputs and the set of outputs; he realises the maximum profit allowed by the technological constraint which limits his possible actions and by the given price system. The aim of this study …
Co-simulation and Formal Verification of Co-operative Drone Control With Logic-Based Specifications
2021
Abstract Unmanned aerial vehicle (UAV) co-operative systems are complex cyber-physical systems that integrate a high-level control algorithm with pre-existing closed implementations of lower-level vehicle kinematics. In model-driven development, simulation is one of the techniques that are usually applied, together with testing, in the analysis of system behaviours. This work proposes a method and tools to validate the design of UAV co-operative systems based on co-simulation and formal verification. The method uses the Prototype Verification System, an interactive theorem prover based on a higher-order logic language, and the Functional Mock-up Interface, a widely accepted standard for co-…
Review of Carruthers (2006): The Architecture of the Mind
2010
Discrete and Conservative Factorizations in Fib(B)
2021
AbstractWe focus on the transfer of some known orthogonal factorization systems from$$\mathsf {Cat}$$Catto the 2-category$${\mathsf {Fib}}(B)$$Fib(B)of fibrations over a fixed base categoryB: the internal version of thecomprehensive factorization, and the factorization systems given by (sequence of coidentifiers, discrete morphism) and (sequence of coinverters, conservative morphism) respectively. For the class of fibrewise opfibrations in$${\mathsf {Fib}}(B)$$Fib(B), the construction of the latter two simplify to a single coidentifier (respectively coinverter) followed by an internal discrete opfibration (resp. fibrewise opfibration in groupoids). We show how these results follow from thei…
Education Students’ Use of Collaborative Writing Tools in Collectively Reflective Essay Papers
2014
Published version of an article in the journal: Journal of Information Technology Education: Research. Also available from the publisher at: http://www.jite.org/documents/Vol13/JITEv13ResearchP091-120Brodahl0463.pdf Open Access Google Docs and EtherPad are Web 2.0 tools providing opportunity for multiple users to work online on the same document consecutively or simultaneously. Over the last few years a number of research papers on the use of these collaborative tools in a teaching and learning environment have been published. This work builds on that of Brodahl, Hadjerrouit, and Hansen (2011) expanding its case study. The theoretical framework is the same as the one underlying Brodahl et a…
Tabu search for min-max edge crossing in graphs
2020
Abstract Graph drawing is a key issue in the field of data analysis, given the ever-growing amount of information available today that require the use of automatic tools to represent it. Graph Drawing Problems (GDP) are hard combinatorial problems whose applications have been widely relevant in fields such as social network analysis and project management. While classically in GDPs the main aesthetic concern is related to the minimization of the total sum of crossing in the graph (min-sum), in this paper we focus on a particular variant of the problem, the Min-Max GDP, consisting in the minimization of the maximum crossing among all egdes. Recently proposed in scientific literature, the Min…
Languages with mismatches
2007
AbstractIn this paper we study some combinatorial properties of a class of languages that represent sets of words occurring in a text S up to some errors. More precisely, we consider sets of words that occur in a text S with k mismatches in any window of size r. The study of this class of languages mainly focuses both on a parameter, called repetition index, and on the set of the minimal forbidden words of the language of factors of S with errors. The repetition index of a string S is defined as the smallest integer such that all strings of this length occur at most in a unique position of the text S up to errors. We prove that there is a strong relation between the repetition index of S an…