3,510 research outputs found

    Independent Orbiter Assessment (IOA): Analysis of the crew equipment subsystem

    Get PDF
    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical (PCIs) items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results coresponding to the Orbiter crew equipment hardware are documented. The IOA analysis process utilized available crew equipment hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 352 failure modes analyzed, 78 were determined to be PCIs

    STD Services Delivery Arrangements in Georgia County Health Departments

    Get PDF
    Background: Uniformity, standardization, and evidence-based public health practice are needed to improve the efficiency and quality of services in local health departments (LHDs). Among the highest priority and most common public health services delivered by LHDs are services related to sexually transmitted diseases (STDs) and sexually transmitted infections (STIs).Objective: The purpose of this study was to examine potential variations in the delivery of sexually transmitted disease (STD) services among county health departments (CHD) in Georgia, to determine if potential variations were due to varied administrative practices, and to understand delivery arrangements so that future cost studies can be supported.Methods: Web-based surveys were collected from 134 county health departments in Georgia in 2015.Results: Screening for gonorrhea, chlamydia and syphilis occurred in all the surveyed CHDs. Sixty-eight percent of the CHDs had one or more staff who performed investigations for persons already screened positive for STDs. Partner notification services provided by the CHD staff occurred in only 35 percent of the surveyed CHDs.Conclusions: Variances regarding diagnostic methodologies, work time expenditures, and staff responsibilities likely had an influence on the delivery of STD services across Georgia's CHDs. There are opportunities for uniformity and standardization of administrative practices

    Obituary: Alan Grahame Lloyd (1926-1999)

    Get PDF
    Teaching/Communication/Extension/Profession,

    Large isotope effect on TcT_c in cuprates despite of a small electron-phonon coupling

    Full text link
    We calculate the isotope coefficients α\alpha and α∗\alpha^\ast for the superconducting critical temperature TcT_c and the pseudogap temperature T∗T^\ast in a mean-field treatment of the t-J model including phonons. The pseudogap phase is identified with the dd-charge-density wave (dd-CDW) phase in this model. Using the small electron-phonon coupling constant λd∌0.02\lambda_d \sim 0.02 obtained previously in LDA calculations in YBa2_2Cu3_3O7_7, α∗\alpha^{\ast} is negative but negligible small whereas α\alpha increases from about 0.03 at optimal doping to values around 1 at small dopings in agreement with the general trend observed in many cuprates. Using a simple phase fluctuation model where the dd-CDW has only short-range correlations it is shown that the large increase of α\alpha at low dopings is rather universal and does not depend on the existence of sharp peaks in the density of states in the pseudogap state or on specific values of the phonon cutoff. It rather is caused by the large depletion of spectral weight at low frequencies by the dd-CDW and thus should also occur in other realizations of the pseudogap.Comment: 8 pages, 5 figures, to be publ. in PR

    A multi-agent based system to enable strategic and operational design coordination

    Get PDF
    This paper presents two systems which individually focus on different aspects of design coordination, namely strategic and operational. The systems were developed in parallel and individually contain related models that represent specific frames from a Design Coordination Framework developed by Andreasen et al. [1]. The focus of the strategic design management system is the management of design tasks, decisions, information, goals and rationale within the design process, whereas the focus of the operational design coordination system is the coordination of tasks and activities with respect to the near-optimal utilisation of available resources. A common interface exists which enables the two systems to be integrated and used as a single system with the aim of managing both strategicand operational design coordination. Hence, the objective of this work is to enable the design process to be conducted in a timely and appropriate manner

    Coordination approaches and systems - part II : an operational perspective

    Get PDF
    This is the second of two papers surveying research in coordination approaches and systems. This paper is concerned with operational coordination, which is aimed at coordinating activities such that the design process can be performed in a near optimal manner with respect to time, and the allocation and utilisation of resources. Aspects of coordination categorised as operational include resource management, scheduling and planning. The first of these two papers presents a review of coordination from a strategic perspective, which is concerned with the decision management aspects of coordination. Greater emphasis is now being placed on the significance of organising the design process as this affects time to market, product quality, cost, and consequently product success. The aim of this paper is to present a fundamental review of operational coordination approaches and systems. The 1990s has seen much progress being made towards a greater understanding and appreciation of coordination in various disciplines through the development of a wide range of approaches and systems. However, there remains a requirement to formally identify the key issues involved in coordination such that a widely accepted representation can be agreed upon. Consequently, research should continue to be supported in the exploration for a unified approach to coordination which will permit a broader and greater understanding of those aspects involved

    A system for co-ordinating concurrent engineering

    Get PDF
    Design of large made-to-order products invariably involves design activities which are increasingly being distributed globally in order to reduce costs, gain competitive advantage and utilise external expertise and resources. Designers specialise within their domain producing solutions to design problems using the tools and techniques with which they are familiar. They possess a relatively local perception of where their expertise and actions are consumed within the design process. This is further compounded when design activities are geographically distributed, resulting with the increased disassociation between an individual designer's activities and the overall design process. The tools and techniques used by designers rarely facilitate concurrency, producing solutions within a particular discipline without using or sharing information from other disciplines, and seldom considering stages within the product's life-cycle other than conceptual, embodiment or detail [1, 2]. Conventional management and maintenance of consistency throughout the product model can subsequently become difficult to achieve since there are many factors that need to be simultaneously considered whilst making achange to the product model
    • 

    corecore