Applied Research Corporation (United States)

As the complexity of systems and systems-of-systems (SoS) has grown, so have the challenges for organizations to create, share, and utilize them effectively. To better address these challenges, it is necessary to create and apply ideas, principles, procedures, and modeling tools to support decision-making in an architectural framework. The use of architecture-based processes is now a common practice in commercial, government, civil, and military domains. The concept of a reference architecture used in this document goes beyond the traditional use where the architecture entity is a system. This allows for a more generalized usage of architecture when the processes in this document are applied. These entities are becoming more complex and architecture practices are increasingly adopted to manage the complexity. Within enterprises and the engineering disciplines, that is an increasing awareness of the value added by architecture, both as a practice and in the realization of artifacts that guide engineering and management activities. The purpose of this document is to provide an understanding of the standard of performance for the governance, management, conceptualization, evaluation and elaboration of architectures, and activities that enable these processes. This document can be used as a process reference model in establishing architecture practice and be applied across a range of contexts and situations.

This study presents an application of the naphthalene sublimation technique to examine the manner in which solid fuels utilized in air-breathing engines may be expected to regress under various flow conditions. A counterflow burner rig was used to exhibit the increase in the sublimation rate of naphthalene when subjected to greater levels of shear stress and surface temperatures. Additionally, skin friction sensor data was taken using Ahmic Aerospace’s supersonic wind tunnel, with a naphthalene coated flat plate instrumented with three skin friction sensors installed in the wall of the wind tunnel. It was found that wall shear decreased an average of 11% across the three sensors over the course of four Mach 2.4 wind tunnel runs. This indicates that naphthalene sublimation can be used as an effective tool to study changes in surface roughness and skin friction at supersonic Mach numbers. Future work with Ahmic’s skin friction sensors and thermocouples embedded within cast naphthalene will be conducted in Virginia Tech’s Hypersonic Wind Tunnel at the Advanced Power and Propulsion Laboratory. This will allow for further definition of the skin friction experienced by naphthalene, which can be used to characterize the skin friction experienced by solid fuels in similar flow scenarios. The naphthalene sublimation technique provides analogous data to study the rate and manner of regression of solid fuels which can also be utilized to refine computer models of surface regression.

Abstract We describe the Geophysical Fluid Dynamics Laboratory's CM4.0 physical climate model, with emphasis on those aspects that may be of particular importance to users of this model and its simulations. The model is built with the AM4.0/LM4.0 atmosphere/land model and OM4.0 ocean model. Topics include the rationale for key choices made in the model formulation, the stability as well as drift of the preindustrial control simulation, and comparison of key aspects of the historical simulations with observations from recent decades. Notable achievements include the relatively small biases in seasonal spatial patterns of top‐of‐atmosphere fluxes, surface temperature, and precipitation; reduced double Intertropical Convergence Zone bias; dramatically improved representation of ocean boundary currents; a high‐quality simulation of climatological Arctic sea ice extent and its recent decline; and excellent simulation of the El Niño‐Southern Oscillation spectrum and structure. Areas of concern include inadequate deep convection in the Nordic Seas; an inaccurate Antarctic sea ice simulation; precipitation and wind composites still affected by the equatorial cold tongue bias; muted variability in the Atlantic Meridional Overturning Circulation; strong 100 year quasiperiodicity in Southern Ocean ventilation; and a lack of historical warming before 1990 and too rapid warming thereafter due to high climate sensitivity and strong aerosol forcing, in contrast to the observational record. Overall, CM4.0 scores very well in its fidelity against observations compared to the Coupled Model Intercomparison Project Phase 5 generation in terms of both mean state and modes of variability and should prove a valuable new addition for analysis across a broad array of applications.

The goal of clinical speech analysis is to describe abnormalities in speech production that affect a speaker's intelligibility. Landmark analysis identifies abrupt changes in a speech signal and classifies them according to their acoustic profiles. These acoustic markers, called landmarks, may help describe intelligibility deficits in disordered speech. As a first step toward clinical application of landmark analysis, the present study describes expression of landmarks in normal speech. Results of the study revealed that syllabic, glottal, and burst landmarks consist of 94% of all landmarks, and suggest the effect of gender needs to be considered for the analysis.

Improving the US healthcare system requires not only providing care to the uninsured but also addressing a set of linked organizational and motivational issues, including enhancing the role of wellness and prevention. It is widely acknowledged that system organization is key to healthcare improvement [1]. Previous studies [2, 3] have pointed to separating wellness and prevention services from acute care as a central component of healthcare transformation. Even while chronic and preventable diseases have become the dominant cause of loss of life, incentives and perceptions limit the delivery of services that could prevent them [2]. A complex systems analysis implies that the optimal organizational structure depends critically on the scale of repetition and complexity of tasks to be performed. Applied to health care, the separation of acute care from selected preventive services should enable improved matching of organizational structure to function [3–5].

Dynamic surface tension data for selected nonionic surfactants, pesticides and other miscellaneous liquids are presented. Surface tension was measured using the oscillating jet technique at surface ages ranging from 0.5 to 7 ms. These early measurements are particularly important since new surfaces are being rapidly created, and they represent the time frame of spray droplet formation and impaction processes.

This article presents calculations of surface water balance for the African continent using a revised version of the Lettau climatonomy. Calculations are based on approximately 1400 rainfall stations, with records generally covering 60 yr or longer. Continental maps of evapotranspiration, runoff, and soil moisture are derived for January, July, and the annual mean. The model is also used to provide a gross estimate of the interannual variability of these parameters over most of the continent and local water balance calculations for a variety of locations in Africa. The results are compared with four other comprehensive global water balance studies. The results of this study are being used to produce a 1° × 1° gridded dataset for the continent, with potential applications for numerical modeling studies.