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In a non-uniform Constraint Satisfaction problem CSP(Γ), where G is a set of relations on a finite set A, the goal is to find an assignment of values to variables subject to constraints imposed on specified sets of variables using the relations from Γ. The Dichotomy Conjecture for the non-uniform CSP states that for every constraint language \Gm the problem CSP(Γ)...
Clustering is a classic topic in optimization with k-means being one of the most fundamental such problems. In the absence of any restrictions on the input, the best known algorithm for k-means with a provable guarantee is a simple local search heuristic yielding an approximation guarantee of 9+≥ilon, a ratio that is known to be tight with respect to such methods.We overcome this barrier...
We consider questions that arise from the intersection between theareas of approximation algorithms, subexponential-time algorithms, and fixed-parameter tractable algorithms. The questions, which have been asked several times (e.g., [Marx, 2008; Fellow et al., 2012; Downey & Fellow 2013]) are whether there is a non-trivial FPT-approximation algorithm for the Maximum Clique (Clique) and Minimum...
In this paper we introduce the notion of lockable obfuscation. In a lockable obfuscation scheme there exists an obfuscation algorithm Obf that takes as input a security parameter, a program P, a message msg and lock value lck and outputs an obfuscated program oP. One can evaluate the obfuscated program oP on any input x where the output of evaluation is the message msg if P(x) = lck and otherwise...
Spreadsheets serve as a basis for decision-making processes in many companies and bugs in spreadsheets can therefore represent a considerable risk to businesses. Systematic tests can help to locate such bugs, but providing test cases can be cumbersome and complex for large real-world spreadsheets. To make the specification of test cases easier, we propose to split spreadsheets into smaller logically...
The vision is considered the most important sense in humans, the visual field may be affected by various diseases or conditions that can even be congenital, resulting in a high percentage of people with visual problems, low vision to blindness. In the majority of cases can be corrected with conventional methods, however, if a suitable control could be prevented and up to early detection of various...
The proposal of the Mexican standard for interoperability is intended to support higher education institutions on implementing inter-institutional collaboration schemes through interoperability of software systems aimed to store and display learning objects. The proposal consists of four volumes: Volume 1. Theoretical Framework for Interoperability of Learning Objects Environments, Volume 2. Determination...
This work-in-progress paper describes an exploratory investigation of the relationship between Grit and retention of engineering students. Grit is a noncognitive trait that psychologists have used to predict success more accurately than cognitive traits like intelligence. We administered the Grit Scale in a first-year engineering design project course (n = 465). Using binary logistic regression, we...
Automatic grading systems, such as WebWork, are becoming much more widely used as they relieve the instructor from needing to grade student work, provide students with automatic feedback, and can allow for immediate resubmission. They have also been shown to improve the effectiveness of teaching and learning. In this paper, we apply Item Response Theory (IRT) to a large WebWork Calculus homework dataset...
Standard applications are unable to perform well in delay- and disruption-tolerant networks (DTNs) due to frequent lack of end-to-end connectivity and long communication delays. Such applications must be thus adapted to be able to operate in disadvantageous network conditions. In a previous work on adapting standard tactical applications for DTN networks, we proposed how such an adaptation may be...
Adapting an educational environment to students considering its features and individuals is a necessity due to the large amount of learning objects in the repositories. Thus, organizing learning objects so that they can be efficiently recommended is a real need. In this way, this work presents a proposal for clustering learning objects in repositories considering the learning styles they support,...
Many natural combinatorial problems can be expressed as constraint satisfaction problems. This class of problems is known to be NP-complete in general, but certain restrictions on the form of the constraints can ensure tractability. The standard way to parametrize interesting subclasses of the constraint satisfaction problem is via finite constraint languages. The main problem is to classify those...
This paper considers a problem of reconstructing a typeface of Chinese characters. First, Chinese characters are generated by using the so-called dynamic font method as a basic tool. Then, we develop a scheme for reconstructing characters to cursive characters with natural "Renmen" which can depict continuity of the adjacent strokes. For realizing the natural Renmen, we propose a method...
The conflict over the Asian Infrastructure Investment Bank (AIIB) involving China, the United States of America (USA), and Japan is analyzed within the paradigm of the Graph Model for Conflict Resolution to gain strategic insights and to predict the possible compromise resolutions. The conflict starts after China proposed in October 2013 the establishment of the AIIB. The USA and Japan opposed the...
In this note, we investigate the fixed time consensus in probability for stochastic multi-agent systems under undirected graph. First, a nonlinear consensus protocol with Gaussian white noise is given, and the concept of fixed-time consensus in probability is given. Second, we prove that multi-agent systems can achieve fixed-time consensus in probability under undirected topology by using graph theory,...
Providing feedback to learners on their writing assignments is one of the most important and time-consuming tasks that a supervisor performs. In e-Education environments, especially in the case of distance learning, giving feedback becomes more challenging because there are often no opportunities for face-to-face interaction. Typically, a supervisor provides comments to learners in written form via...
This work is devoted to the admissibility analysis for singular time-delay systems by using delta operator approach. By estimating the delay term with a two-term approximation, the singular system in delta operator domain is transformed into an interconnection of a time-invariant subsystem with constant delay and a uncertain one. By resorting to the input-output approach, a delay-range-dependent admissibility...
This paper is concerned with the admissibility analysis for a kind of stochastic singular delayed systems (SSDSs). Sufficient conditions for the regularity of the impulse-free solution to the SSDSs are obtained. Consequently, by formulating Lyapunov-Krasovskii functional and applying Ito formula, novel sufficient conditions for the stability of SSDSs are derived in terms of strict linear matrix inequalities...
Mutation testing of object-oriented programs differs from that of standard (traditional) mutation operators in accordance to the number of generated mutants and ability of tests to kill mutants. Therefore, outcomes of cost reduction analysis cannot be directly transferred from a standard mutation to an object-oriented one. Mutant sampling is one of reduction methods of the number of generated and...
With the high-speed railway put into operation, the types of trains in the existed line is reduced, train intervals will also be shortened. We analyze the impact of high-speed rail's operations on the basis of the calculation method of the interval passing capacity in existed line, for example in three major areas : the difference of train running time in the section, the proportion of trains dispatched...
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