Analysis of Possible Solutions to Support the Timely Delivery of the Columbia-Class Submarine

Symposium Student Poster ShowStrategic deterrence is the number one priority of the Department of Defense. In order to prevent a gap in nuclear deterrent capability, the successor to the Ohio class, the Columbia class, must be built according to schedule. However, the Columbia-class submarine has experienced numerous schedule delays which threaten its timely delivery. This thesis conducts a root cause analysis of the issues which have contributed to schedule delays and proposes a way moving forward which minimizes the likelihood of future setbacks. These issues are framed in a fictitious case study and the recommendations to solve the problems are discussed in a follow-on analysis.Approved for public release; distribution is unlimited

ANALYSIS OF POSSIBLE SOLUTIONS TO SUPPORT THE TIMELY DELIVERY OF THE COLUMBIA CLASS SUBMARINE

Ballistic missile submarines (SSBNs) are a stealthy, survivable launch platform that contributes to strategic deterrence, the number one mission of the Department of Defense. Ohio-class SSBNs, which have filled the role of sea-based deterrence for the last 40 years, are reaching their retirement criteria. In order to prevent a gap in nuclear deterrent capability, the successor to the Ohio-class, the Columbia-class, must be built according to schedule. However, the Columbia-class submarine is experiencing setbacks due to multiple issues with the software used to generate key design documents, an industrial base that is struggling to support the construction of three submarines per year (two Virginia-class fast attack submarines and one Columbia-class SSBN), and quality assurance issues with key manufacturers. With a mission as important as strategic deterrence on the line, developing a useful solution quickly is of the highest importance. This research analyzed the Columbia-class submarine acquisition program, generated a case study, and concluded with a case study analysis that utilizing the Defense Production Act Title III, which could re-bolster the submarine industrial base, and fully restoring and improving existing quality assurance programs, could increase the likelihood of delivering the first Columbia-class submarine on schedule while also optimizing for cost, performance, and technological risk.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

Bidirectional ventricular tachycardia in cardiac sarcoidosis.

A 73-year-old man with history of pulmonary sarcoidosis was found to have runs of non-sustained bidirectional ventricular tachycardia (BVT) with two different QRS morphologies on a Holter monitor. Cardiac magnetic resonance delayed gadolinium imaging revealed a region of patchy mid-myocardial enhancement within the left ventricular basal inferolateral myocardium. An 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed increased uptake in the same area, consistent with active sarcoid, with no septal involvement. Follow-up FDG-PET one year later showed disease progression with new septal involvement. Cardiac sarcoidosis, characterized by myocardial inflammation and interstitial fibrosis that can lead to conduction system disturbance and macro re-entrant arrhythmias, should be considered in differential diagnosis of BVT. BVT may indicate septal involvement with sarcoidosis before the lesions are large enough to be detected radiologically

Building Social Capital Through Microfinance

A number of development assistance programs promote community interaction as a means of building social capital. Yet, despite strong theoretical underpinnings, the role of repeat interactions in sustaining cooperation has proven difficult to identify empirically. We provide the first experimental evidence on the economic returns to social interaction in the context of microfinance. Random variation in the frequency of mandatory meetings across first-time borrower groups generates exogenous and persistent changes in clients' social ties. We show that the resulting increases in social interaction among clients more than a year later are associated with improvements in informal risk-sharing and reductions in default. A second field experiment among a subset of clients provides direct evidence that more frequent interaction increases economic cooperation among clients. Our results indicate that group lending is successful in achieving low rates of default without collateral not only because it harnesses existing social capital, as has been emphasized in the literature, but also because it builds new social capital among participants

Building Social Capital Through MicroFinance

A number of development assistance programs promote community interaction as a means of building social capital. Yet, despite strong theoretical underpinnings, the role of repeat interactions in sustaining cooperation has proven difficult to identify empirically. We provide the first experimental evidence on the economic returns to social interaction in the context of microfinance. Random variation in the frequency of mandatory meetings across first-time borrower groups generates exogenous and persistent changes in clients' social ties. We show that the resulting increases in social interaction among clients more than a year later are associated with improvements in informal risk-sharing and reductions in default. A second field experiment among a subset of clients provides direct evidence that more frequent interaction increases economic cooperation among clients. Our results indicate that group lending is successful in achieving low rates of default without collateral not only because it harnesses existing social capital, as has been emphasized in the literature, but also because it builds new social capital among participants.

Numerical simulation of colloidal dispersion filtration: description of critical flux and comparison with experimental results

During filtration via membrane processes, colloids accumulate at the porous surface leading to fouling phenomena. In this study, a rigorous simulation of momentum and mass transfer using CFD modelling has been developed to describe such an accumulation during cross flow filtration. These simulations integrate detailed modeling of physicochemical properties specific to colloidal dispersions (because of the surface interactions (repulsive and attractive) occurring between the colloids particles). These interactions are accounted for via the experimental variation of the colloidal osmotic pressure with volume fraction (associated with a variation in the diffusion coefficient) which are fitted by a relationship integrated into the CFD code. It contains a description of the colloidal phase transition leading to the formation of a condensed phase (deposit or gel layer) from the accumulated dispersed phase (concentration polarization). It is then possible to determine the critical flux which separates filtration conditions below which mass accumulation is reversible (in the dispersed phase) and above which it is irreversible (in the condensed phase). The computed value of critical flux is compared with that determined experimentally for a dispersion of latex particles

Upper Limb Capabilities, Self-Care and Fine Motor Activities with and Without Equipment in Persons with Cervical Spinal Cord Injury at Discharge from Rehabilitation and 1 Year Post-Injury

Introduction: There is little information on the impact of assistive technology or devices (AT) on function. The purpose of this project was to explore the impact of AT on self-care (SC) and fine motor (FM) function in persons with cervical SCI, and to examine the functional capabilities of those who benefit from AT. Methods: Persons with acute cervical SCI, all levels and AIS grades, with an upper extremity motor score (UEMS) \u3e 0 were enrolled. At discharge from rehabilitation and 1 year post-injury we collected the Capabilities of Upper Extremity questionnaire (CUE-Q), and the combined SC and FM questions of the SCI Functional Index (SCI-FI) and SCI-FI/AT short forms. The arm with the highest CUE-Q side score was designated the better side. The impact of AT on SC and FM function was evaluated by looking at the difference in SCI-FI and SCI-FI/AT scores, and changes over time. Results: There were 67 participants with data at rehab discharge and 1-year post-injury, 50 male and 17 female, average age 43.3 ± 15.6 years. Median scores by neurologic groupings are shown in the table. All groups demonstrated improvements in CUE-Q and SCI-FI scores from discharge to 1 year post-injury (table and radar charts). By neurologic group, AT was useful for the greatest percentage of persons classified as C4-C5 AB for FM and C6-T1 AB for SC), least useful for C6-T1 CD (charts at right). AT was helpful for the greatest number of items for SC in the C4-C5 CD group at discharge (bolded numbers in table). There tended to be less use of AT for tasks at 1 year compared to rehab discharge. For example, the percentage of persons using AT for brushing teeth at discharge was 48%, while at 1 year it was only 25%. Conclusion: Many persons with tetraplegia are able to perform self-care and fine motor tasks easier using AT, but the benefit depends on the level and severity of injury. There is a decreased reliance on AT over time, which may in part be due to continued recovery after rehabilitation discharge.https://jdc.jefferson.edu/rmposters/1013/thumbnail.jp