Machine-type communications (MTC) are a rapidly growing technology, which is expected to generate significant revenues to mobile network operators. In particular, smart grid is predicted to become one of the key MTC use cases that involves unattended meters autonomously reporting information to a grid infrastructure. With this research, we consider a typical smart metering MTC application scena...

We investigate the two-median problem on a mesh with M columns and N rows (M ≥ N ), under the Manhattan (L1) metric. We derive exact algorithms with respect to m, n, and r , the number of columns, rows, and vertices, respectively, that contain requests. Specifically, we give an O(mn2 logm) time, O(r ) space algorithm for general (nonuniform) meshes (assuming m≥n). For uniform meshes, we give tw...

We consider a coalescing particle model where particles move in discrete time. At each time period, each remaining ball is independently put in one of n bins according to a probability distribution p ( p1, . . . , pn), and all balls put into the same bin merge into a single ball. Starting with k balls, we are interested in the properties of E[N(p, k)], the expected time until all balls merge in...

Test suite augmentation techniques are used in regression testing to identify code elements in a modified program that are not adequately tested and to generate test cases to cover those elements. A defining feature of test suite augmentation techniques is the potential for reusing existing regression test suites. Our preliminary work suggests that several factors influence the efficiency and e...

Software security issues have been a major concern in the cyberspace community, so a great deal of research on security testing has been performed, and various security testing techniques have been developed. Threat modeling provides a systematic way to identify threats that might compromise security, and it has been a well-accepted practice by the industry, but test case generation from threat...

Given the continued difficulty of developing geometric multigrid methods that provide robust convergence for unstructured discretizations of compressible flow problems in aerodynamics, we turn to algebraic multigrid (AMG) as an alternative with the potential to automatically deal with arbitrary sources of stiffness on unstructured grids. We show here that AMG methods are able to solve linear pr...

We consider standard robust adaptive control designs based on the dead-zone and projection modifications, and compare their performance w.r.t. a worst case transient cost functional penalizing the L norm of the output, control and control derivative. If a bound on the L norm of the disturbance is known, it is shown that the dead-zone controller outperforms the projection controller if the a pri...

Deliberative reasoning based on the rational analysis of various alternatives often requires too much information and may be too slow in time critical situations. In these situations, humans rely mainly on their intuitions rather than some structured decision-making processes. An important and challenging problem in Military Operations on Urban Terrain (MOUT) simulations is how to generate real...

In this article, we design and analyze algorithms that solve the unranking problem (i.e., generating a combinatorial structure of size, n given its rank) for a large collection of labeled combinatorial classes, those that can be built using operators like unions (+), products ( ), sequences, sets, cycles, and substitutions. We also analyze the performance of these algorithms and show that the w...

We propose a new test case prioritization technique that combines both mutation-based and diversity-based approaches. Our diversity-aware mutation-based technique relies on the notion of mutant distinguishment, which aims to distinguish one mutant’s behavior from another, rather than from the original program. We empirically investigate the relative cost and effectiveness of the mutation-based ...