An Architectural Framework for Performance Analysis: Supporting the Design, Configuration, and Control of DIS /HLA Simulations

Technology advances are providing greater capabilities for most distributed computing environments. However, the advances in capabilities are paralleled by progressively increasing amounts of system complexity. In many instances, this complexity can lead to a lack of understanding regarding bottlenecks in run-time performance of distributed applications. This is especially true in the domain of distributed simulations where a myriad of enabling technologies are used as building blocks to provide large-scale, geographically disperse, dynamic virtual worlds. Persons responsible for the design, configuration, and control of distributed simulations need to understand the impact of decisions made regarding the allocation and use of the logical and physical resources that comprise a distributed simulation environment and how they effect run-time performance. Distributed Interactive Simulation (DIS) and High Level Architecture (HLA) simulation applications historically provide some of the most demanding distributed computing environments in terms of performance, and as such have a justified need for performance information sufficient to support decision-makers trying to improve system behavior. This research addresses two fundamental questions: (1) Is there an analysis framework suitable for characterizing DIS and HLA simulation performance? and (2) what kind of mechanism can be used to adequately monitor, measure, and collect performance data to support different performance analysis objectives for DIS and HLA simulations? This thesis presents a unified, architectural framework for DIS and HLA simulations, provides details on a performance monitoring system, and shows its effectiveness through a series of use cases that include practical applications of the framework to support real-world U.S. Department of Defense (DoD) programs. The thesis also discusses the robustness of the constructed framework and its applicability to performance analysis of more general distributed computing applications

Evaluating Obselete Inventory Policies in a Hospital\u27s Supply Chain

Numerous organizations are currently facing inventory management problems including distributing inventory on time and maintaining the appropriate inventory level to satisfy the end user. Organizations understand the importance of inventory accuracy as any error will increase the purchasing and holding costs affecting investment decisions. Lack of information about effective measures that will allow management to make important business decisions motivated this research to identify a decision criterion for warehouse management. A feasible solution of calculating the carrying cost ratio from purchasing and holding cost is the main objective of this thesis. The carrying cost ratio will allow managers to make critical decisions on supply-chain management. Similar to the carrying cost ration, this thesis also provides a methodology for warehouse management using inventory turns that can be used to identify obsolete inventory. Friedman’s Rank test was performed to validate the decision using primary turns for the dataset obtained from a local hospital. Recommendations have been made to the hospital to facilitate their supply chain that will result in the reduction of excessive inventory. A reduced carrying cost ratio demonstrates consolidating commodities into fewer facilities. The future benefits for the current organization include a reduce building and facility costs, decrease in annual operating budgets, reduction in warehouse operational cost, improvement in labor productivity, warehouse space utilization, and establish performance measures. In conclusion, findings from this research will allow organization to move towards the one-echelon model known as Just-In-Time (JIT) system

Characterization of Dextromethorphan And Dextrorphan Uptake by a Putative Glutamic Acid Carrier and Passive Diffusion Across Brain Microvessel Endothelium

Read More: http://informahealthcare.com/doi/abs/10.3109/10717549309022764The mechanisms of uptake and transcellular passage of dextromethorphan (DM) and its major metabolite dextrorphan (DX) across the endothelial component of the blood–brain barrier have been investigated with primary cultures of bovine brain microvessel endothelial cells (BMECs). The uptake of [14C]DM and [14C]DX by BMECs was observed to be temperature-sensitive and saturable, with approximate Km's of 0.12 and 0.29 mM and Vmax's of 9.2 and 11.0 pmol/mg/min, respectively. The BMEC uptake of [14C] DM was inhibited half-maximally by approximately 0.57 mM L-glutamic acid, 0.71 mM N-methyl-d-asparatate (NMDA), and 0.99 mM DL-threo-β-hydroxyaspartic acid. The BMEC uptake of [14C]DX was inhibited half-maximally by approximately 0.48 mM L-glutamic acid, 1.50 mM NMDA, and 0.69 mM DL-threo-β-hydroxyaspartic acid. Conversely, the bidirectional passage of DM and DX across confluent BMEC monolayers occurred at a faster rate but was neither saturable nor inhibited by high concentrations of glutamic acid, NMDA, or unlabeled DM or DX. These results suggest that DM and DX are capable of interacting with a low-capacity glutamic acid-type carrier mechanism on the apical surface of BMECs. However, the net transfer of these agents across BMEC monolayers appeared to be more rapid and passive in nature