In this paper we briefly describe a software architecture that integrates reactivity and dehberation. The architecture has three levels, or tiers. The bottom tier contains a set of situated, reactive skills. The second tier is a sequencer that can activate sets of skills to perform a task. The third tier is a planner that reasons in-depth about goals, resources and constraints. We characterize ...

The cμ rule is known to be optimal in many queueing systems with memoryless service and inter-arrival times. We establish a cμ rule for a parallel flexible server system with two tiers. Multiple job classes arrive and wait in separate queues. The first tier contains classes that can only be served by one server each, and the second tier contains a class that can be served by all servers. The cμ...

In this contribution, we consider a heterogeneous two-tiered network where a tier of cognitive self-organizing small cells is deployed over the coverage area of a preexisting orthogonal frequency division multiple access (OFDMA) macro cell. Neither crossnor co-tier cooperation or communication is established, thus no joint signal processing techniques can be implemented by the macro and small b...

The cμ rule is known to be optimal in many queueing systems with memoryless service times. We establish a cμ rule for a parallel flexible server system with two tiers. Multiple job classes arrive and wait in separate queues. The first tier contains classes that can only be served by one server and the second tier contains a class that can be served by all servers. The cμ preferences give priori...

The current recommendation for the laboratory confirmation of Lyme disease is serology-based diagnostics. Specifically, a standardized two-tiered testing (STTT) algorithm is applied that utilizes a first-tier immunofluorescence assay or enzyme immunoassay (EIA) that, if the result is positive or equivocal, is followed by second-tier immunoblotting. Despite the standardization and performance ac...

We performed a two-tiered, whole-genome association study of Parkinson disease (PD). For tier 1, we individually genotyped 198,345 uniformly spaced and informative single-nucleotide polymorphisms (SNPs) in 443 sibling pairs discordant for PD. For tier 2a, we individually genotyped 1,793 PD-associated SNPs (P<.01 in tier 1) and 300 genomic control SNPs in 332 matched case-unrelated control pairs...

Although cluster-based multi-tier data centers provide a means for supporting scalable web applications, their ad-hoc configuration poses significant challenges to the performance and economical costs of multi-tier applications. This paper presents the design and implementation of MoKaa utilityaware framework for modeling multi-tier data centers and planning their capacity and optimal configura...

In recent years dozens of nations have begun exporting software products and services. We label these nations the “new software exporting nations”. We introduce a four-tier taxonomy of software exporting nations. Thresholds for the tiers are defined by export revenues, by cluster size, and by maturity. Tier 1 nations are the major software exporting nations; Tier 2 nations are the transition so...