Security administration is harder in databases that have multiple tiers of derived data, such as federations, warehouses, or systems with many views. Metadata (e.g., security requirements) expressed at each tier must be visible and understood at the other tier. We describe several use cases in which tiers negotiate to reconcile their business requirements. The sources must grant enough privileg...

Hierarchical architectures are more and more widely adopted for organizing wireless sensor networks. In such architectures, middle-tier nodes take important roles, and preventing a malicious node from impersonating a middle-tier node and injecting falsified messages becomes critical. In this paper, we propose an energy efficient, distributed scheme to secure the multicast messages from the midd...

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...

This paper introduces a domain-specific language for modelling and simulationbased design of multi-tier systems. Multi-tier systems are complex and very few general models have been developed. Rather, models are always dedicated to a specific architecture. Our approach allows for rapid experimentation with different multi-tier alternatives. Not only parameters, but also structure can be drastic...

BACKGROUND Expenditures for medications used to treat attention-deficit/hyperactivity disorder (ADHD) in children have increased rapidly. Many employers and health plans have adopted 3-tier formularies in an attempt to control costs for these and other drugs. OBJECTIVE To assess the effect of copayment increases associated with 3-tier formulary adoption on use and spending patterns for ADHD m...

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...

OBJECTIVE To evaluate the impact of 3-tier (copayment) pharmacy benefit structures on medication utilization behavior. METHODS A pretest-posttest quasi-experimental design was employed. Chronic disease sufferers (N=8,132) from a health plan were classified into the following groups: (a) 2-tier copayment moving to a 3-tier structure, (.converting. group), (b) 2-tier staying in a 2-tier structu...

A manufacturer must choose whether to delegate component procurement to her tier-1 supplier, or control it directly. Due to information asymmetry about suppliers’ production costs and the use of simple quantity discount or price-only contracts, either delegation or control can yield substantially higher expected profit for the manufacturer. Delegation tends to outperform control when (1) the ma...

The paper explores the impact that modularization is having on the structure of supply chains in general and on the role of Ž rst-tier suppliers in particular. Two concepts are presented to illustrate Ž rstly the need to redeŽ ne the term ‘Ž rst-tier’ supplier and secondly to determine how and why value can be transferred within a modular supply chain. The Ž rst concept, the ‘continuum of Ž rst...