An important problem in Neuroscience is to determine the brain active regions given the measured electrical potentials on the scalp. This problem is called "the source localization problem". An accurate solution to this problem will provide an opportunity to access the active cortex region non-invasively. This knowledge can help neurologist in the treatment of epilepsy patients and can help psychologist to better understand the brain functions.
Harnessing the power of Microsoft's Xbox 360 video game console was previously a privilege extended to sizable video game studios with large development teams and equally large budgets. Now, with a new technology from Microsoft called XNA Game Studio Express, the console has been opened up to hobbyists, students, and anyone with a desire to see their video game ideas come to life.
Task-based executions have been shown to be successful for homogeneous parallel systems for many scientific applications providing a suitable degree of task parallelism. In this talk, a task-based programming model for heterogeneous systems and Grid environments is discussed. These environments need a dynamic scheduling because of a dynamically changing load and availability of the computing resources. Thus, a suitable representation of the execution activities is required where tasks can be shipped to remote computing resources for execution.
One version of the satisfiability problem involves finding the lexicographically maximum satisfying (lex max sat) assignment for a given boolean formula. The decision version of this problem asks whether the lex max sat assignment is odd. This problem is the canonical Delta2-Complete problem. I will show that it is Delta2-Complete using a direct Cook-style reduction which demonstrates how to represent oracle turing machines using boolean formula.
Pex (Program EXploration) is a test generation tool for .NET programs. Pex systematically enumerates feasible execution paths of the program-under-test using a technique based on Directed Automated Random Testing (DART). In this variant of symbolic execution, the program is executed repeatedly, initially with random inputs. The taken execution path is monitored and a symbolic representation of the path condition is obtained. The negation of the path condition gives rise to more execution paths using a constraint solver.
Adaptive Programming (AP), developed as an extension to OO in the 90s, separates the concern of where to navigate on objects (WHERE-TO-GO) from the concern of what to do during the navigation (WHAT-TO-DO). The history-based navigation abstractions provided by AP allow modifications to the underlying object topology without affecting its associated computation. We call such programs structure-shy because they withstand some changes to the underlying data-structure.
An acyclic edge colouring of a graph is a proper edge colouring in which there is no bichromatic (2-colored) cycle. That is, the union of any two color classses forms a forest. Acyclic chromatic index is the minimum number of colors used in such a colouring. Estimating the acyclic chromatic index is an interesting and difficult problem both from a theoretical and an algorithmic point of view and has potential applications in scheduling. Even for highly structured graphs, this number is yet to be determined.
[This is a talk to be given at the History of Programming Languages (HOPL) conference. HOPL takes place every 15 years, so this is a unique opportunity to hear about a historic account of the design and development of an influential programming language.]
We will take a closer look at one of cryptography's least flashy, yet most widely used objects, the hash function. The cryptographic community has been shocked over the last three years by a series of attacks on MD5 (broken), SHA-0 (broken), SHA-1 (teetering) and others. In response, NIST is preparing to call for an international competition to design the next generation of hashing algorithms. Now seems like a good time to revisit exactly what are these objects, what they are supposed to do for us, and how we go about constructing them.
Digital identity management (DIM) has emerged as a critical foundation for supporting successful interaction in today's globally interconnected society. It is crucial not only for the conduct of business and government but also for a large and growing body of electronic or online social interactions. Digital identity management is usually coupled with the notion of federation. The goal of federations is to provide users with protected environments to federate identities by the proper management of identity attributes.