Eventually and weakly consistent distributed systems have emerged in the past decade as an answer to scalability and availability issues associated with strong consistency semantics, such as linearizability. However, systems offering strong consistency semantics have an advantage over systems based on weaker consistency models, as they are typically much simpler to reason about and are more int...

Classical approaches to visualization directly reduce a document’s high-dimensional representation into visualizable two or three dimensions, using techniques such as multidimensional scaling. More recent approaches consider an intermediate representation in topic space, between word space and visualization space, which preserves the semantics by topic modeling. We call the latter semantic visu...

Modern multiprocessors only provide weak memory consistency that deviates from the traditional sequential consistency in many unintuitive ways: In essence, the read and write operations issued by one processor might be observed by other processors in a different order than executed by the issuing processor. It is therefore strongly recommended to formally verify multithreaded systems. To this e...

Shared memory systems provide a contract to the programmer in the form of a consistency condition. The conditions of atomic memory and sequential consistency provide the illusion of a single memory module, as in the uniprocessor case. Weaker conditions improve performance by sacriicing the simple programming model. Consistency conditions are formulated without reference to details of the hardwa...

Concurrent threads of execution running on a shared memory system can access the same memory locations. A consistency model defines constraints on the order of these shared memory accesses. For good run-time performance, these constraints must be as few as possible. Programmers who write explicitly parallel programs must take into account the consistency model when reasoning about the behavior ...

We introduce a probabilistic graphical model of ranked preferences for social choice based on a restricted version of a kth-order Markov tree. The system is similar to Plackett’s model, and is based on the intuition that, in some domains, an agent’s next most preferred alternative is highly predictable given a few of the immediately preceding alternatives. We provide a bound on the data require...

We consider the estimation of the number of hidden states (the order) of a discrete-time finite-alphabet hidden Markov model (HMM). The estimators we investigate are related to code-based order estimators: penalized maximum-likelihood (ML) estimators and penalized versions of the mixture estimator introduced by Liu and Narayan. We prove strong consistency of those estimators without assuming an...