Parallel simulation of multiprocessor architectures is a promising direction because a parallel system provides the high computation and storage capabilities that are required by detailed architectural simulation. Additionally, the behavior of the target system exhibits natural parallelism. In this paper, we consider the evaluation of the memory hierarchy of multiprocessor systems via parallel ...

Data replication places physical copies of a shared logical item onto different sites. Optimistic replication (OR) allows a program at some site to read or update the local replica at any time. An update is tentative because it may conflict with a remote update. Such conflicts are resolved after the fact, in the background. Replicas may diverge occasionally but are expected to converge eventual...

Mobile ad hoc networks are collections of wireless mobile nodes with links that are made or broken in an arbitrary way. They have constrained resources, restricted broadcast range and no fixed infrastructure. For these networks communication is achieved via routes whose nodes relay packets. Several routing algorithms have been proposed in the literature. These focus mainly on efficiency with se...

This paper presents an Optimistic Atomic Broadcast algorithm (OPT-ABcast) that exploits the spontaneous total order message reception property experienced in local area networks, in order to allow fast delivery of messages. The OPT-ABcast algorithm is based on the Optimistic Consensus problem (OPT-Consensus) that allows processes to decide optimistically or conservatively. A process optimistica...

Credit ratings affect firms’ access to capital and investment choices. We show that the identity of the credit analysts covering a firm significantly affects the firm’s rating, comparing ratings for the same firm at the same time across agencies. Analyst effects account for 30% of the within variation in ratings. Moreover, the rating biases of analysts carry through to credit spreads on the rat...

We propose a simple agent-based macroeconomic model in which firms hold heterogeneous sales expectations. A firm may either optimistically expect an increase in its sales or pessimistically expect the opposite. Whether a given firm is optimistic or pessimistic depends on macroeconomic conditions and the average mood prevailing within its social/local neighborhood. For instance, the probability ...

Linguistic negation processing is a challenging problem studied by a large number of researchers from different communities, i.e. logic, linguistics, etc. We are interested in finding the positive interpretations of a negative sentence represented as ”x is not A”. In this paper, we do not focus on the single set of translations but on two approximation sets. The first one called pessimistic cor...

In this paper, we propose a novel optimistic unchoking approach for the BitTorrent protocol whose key objective is to improve the quality of inter-connections amongst peers. In turn, this yields enhanced data distribution without penalizing underutilized and/or idle peers. The suggested policy takes into consideration the number of peers currently interested in downloading from a client that is...

Replication is attractive for scaling databases up, as it does not require costly equipment and it enables fault tolerance. However, as the latency gap between local and remote accesses continues to widen, maintaining consistency between replicas remains a performance and complexity bottleneck. Optimistic replication (OR) addresses these problems. In OR, a database tentatively executes transact...

This paper, based on the average monthly data (January, 2001 to May, 2013) of 12 macroeconomic variables, uses the data reduction technique-factor analysis to derive the factors which determine the performance of stock market in India. The Principal Component Technique after using orthogonal rotation extracted three factors labeled intuitively as Macro Environment, Industrial Performance and Po...