182 research outputs found

    RS-34 (Peacekeeper Post Boost Propulsion System) Orbital Debris Application Concept Study

    Get PDF
    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) lead a study to evaluate the Rocketdyne produced RS-34 propulsion system as it applies to an orbital debris removal design reference mission. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Concept Study, preceded by a utilization study to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions, sought to further understand application for an orbital debris design reference mission as the orbital debris removal mission was found to closely mimic the heritage RS-34 mission. The RS-34 Orbital Debris Application Concept Study sought to identify multiple configurations varying the degree of modification to trade for dry mass optimization and propellant load for overall capability and evaluation of several candidate missions. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper

    RS-34 Phoenix In-Space Propulsion System Applied to Active Debris Removal Mission

    Get PDF
    In-space propulsion is a high percentage of the cost when considering Active Debris Removal mission. For this reason it is desired to research if existing designs with slight modification would meet mission requirements to aid in reducing cost of the overall mission. Such a system capable of rendezvous, close proximity operations, and de-orbit of Envisat class resident space objects has been identified in the existing RS-34 Phoenix. RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. The National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC) gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC has obtained permission from the USAF to obtain all the remaining RS-34 stages for re-use opportunities. The MSFC Advanced Concepts Office (ACO) was commissioned to lead a study for evaluation of the Rocketdyne produced RS-34 propulsion system as it applies to an active debris removal design reference mission for resident space object targets including Envisat. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy payloads at multiple orbital locations. The RS-34 Concept Study lead by sought to further understand application for a similar orbital debris design reference mission to provide propulsive capability for rendezvous, close proximity operations to support the capture phase of the mission, and deorbit of single or multiple large class resident space objects. Multiple configurations varying the degree of modification were identified to trade for dry mass optimization and propellant load. The results of the RS-34 Phoenix Concept Study show that the system is technically sufficient to successfully support all of the missions to rendezvous, capture, and de-orbit targets including Envisat and Hubble Space Telescope. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper

    Predicting invasive breast cancer versus DCIS in different age groups.

    Get PDF
    BackgroundIncreasing focus on potentially unnecessary diagnosis and treatment of certain breast cancers prompted our investigation of whether clinical and mammographic features predictive of invasive breast cancer versus ductal carcinoma in situ (DCIS) differ by age.MethodsWe analyzed 1,475 malignant breast biopsies, 1,063 invasive and 412 DCIS, from 35,871 prospectively collected consecutive diagnostic mammograms interpreted at University of California, San Francisco between 1/6/1997 and 6/29/2007. We constructed three logistic regression models to predict the probability of invasive cancer versus DCIS for the following groups: women ≥ 65 (older group), women 50-64 (middle age group), and women < 50 (younger group). We identified significant predictors and measured the performance in all models using area under the receiver operating characteristic curve (AUC).ResultsThe models for older and the middle age groups performed significantly better than the model for younger group (AUC = 0.848 vs, 0.778; p = 0.049 and AUC = 0.851 vs, 0.778; p = 0.022, respectively). Palpability and principal mammographic finding were significant predictors in distinguishing invasive from DCIS in all age groups. Family history of breast cancer, mass shape and mass margins were significant positive predictors of invasive cancer in the older group whereas calcification distribution was a negative predictor of invasive cancer (i.e. predicted DCIS). In the middle age group--mass margins, and in the younger group--mass size were positive predictors of invasive cancer.ConclusionsClinical and mammographic finding features predict invasive breast cancer versus DCIS better in older women than younger women. Specific predictive variables differ based on age

    UC-11 Information Recall For Kids With Autism

    Get PDF
    Description: Our project Information Recall For Kids With Autism also known as the product name given by the client Safe Kid is an app to help children with autism understand basic contact information such as phone numbers, addresses, and names. This app is being created for our client Spectrum Behavioral Associates who specialize in helping kids and young adults who have autism, learning development delays, or other behavioral challenges. Motivation: To teach kids who have autism basic contact information in case of an emergency. Materials and Methods: The app we are creating is a local based app made within Unity. The coding language we are using is C# and we are incorporating user centered design to best fit the target audience. Preliminary Results: To change a life for someone who has autism or a friend/family member of someone who has autism. Intellectual or Business Merit: To teach kids basic contact information through sequences and other methods or recalling information. Also for us it would be implementing what we have learned through the years as software engineering students via documentation, user centered design, testing, consulting, and implementing. Actions That Enhance the Potential of Our Projects Benefit to Society: We feel as it is very important to learn basic contact information in case of an emergency. Some kids with autism or other behavioral delays may have a hard time vocalizing the contact information but have no problem writing it down. This could change the lives of many kids and family members of children with autism.Advisors(s): Professor - Dr. Parizi Client - Spectrum Behavioral Associates Personnel - Hannah TaylorTopic(s): GamesSWE 472

    Managing clustering effects and learning effects in the design and analysis of multicentre randomised trials: a survey to establish current practice.

    Get PDF
    BACKGROUND:Patient outcomes can depend on the treating centre, or health professional, delivering the intervention. A health professional's skill in delivery improves with experience, meaning that outcomes may be associated with learning. Considering differences in intervention delivery at trial design will ensure that any appropriate adjustments can be made during analysis. This work aimed to establish practice for the allowance of clustering and learning effects in the design and analysis of randomised multicentre trials. METHODS:A survey that drew upon quotes from existing guidelines, references to relevant publications and example trial scenarios was delivered. Registered UK Clinical Research Collaboration Registered Clinical Trials Units were invited to participate. RESULTS:Forty-four Units participated (N = 50). Clustering was managed through design by stratification, more commonly by centre than by treatment provider. Managing learning by design through defining a minimum expertise level for treatment provider was common (89%). One-third reported experience in expertise-based designs. The majority of Units had adjusted for clustering during analysis, although approaches varied. Analysis of learning was rarely performed for the main analysis (n = 1), although it was explored by other means. The insight behind the approaches used within and reasons for, or against, alternative approaches were provided. CONCLUSIONS:Widespread awareness of challenges in designing and analysing multicentre trials is identified. Approaches used, and opinions on these, vary both across and within Units, indicating that approaches are dependent on the type of trial. Agreeing principles to guide trial design and analysis across a range of realistic clinical scenarios should be considered

    Protocol for intervention development to improve adolescent perinatal mental health in Kenya and Mozambique: The INSPIRE project

    Get PDF
    Introduction: Mental health interventions have traditionally been developed by clinicians and researchers without the meaningful engagement and partnership with those who would receive, deliver, and fund them. Recent progress has highlighted the importance of the co-design of interventions, through stakeholder participation, as a means of increasing the integration of mental health interventions into existing health, education, and social care systems. This protocol describes the pre-implementation phase of the INSPIRE (Innovative approaches to adolescent perinatal wellbeing) project which aims to identify challenges, and design and test interventions to promote mental wellbeing and good mental health of adolescent girls during pregnancy and the year after birth with local stakeholders in Kenya and Mozambique. Methods: A participatory approach that blends human-centred design, systems thinking, and implementation science methods will be used to engage adolescents (aged 15–19 years), their families, and other stakeholders who can influence implementation efforts, in planning and preparing interventions. First, an understanding of context, barriers, and opportunities related to adolescent perinatal mental health will be elicited through individual interviews, focus group discussions, and observations. This will be complemented by a scoping review of relevant interventions. The research team will identify contextual insights relating to adolescent and system characteristics, strengths, and challenges. These will be shared with and refined by stakeholders. Thematic analysis will be conducted to describe the experiences of adolescent girls, and barriers and enablers to maintaining good mental health. The former will be triangulated with the Context and Implementation of Complex Intervention (CICI) framework. Causal loop diagrams will be developed to illustrate the individual and system-level variables which influence adolescent perinatal mental health. Stakeholder workshops will be used to identify priorities, brainstorm potential interventions, develop a program theory, and prototype an intervention and implementation strategies. Intervention acceptability, appropriateness, and feasibility will be assessed, and a theory of change map finalized. Results: To date the study has recruited 169 participants to complete individual interviews, focus group discussions and observation activities. Conclusions: It is anticipated that the use of a participatory and systematic approach to the development of an intervention to improve mental health, will improve its perceived appropriateness, acceptability, and feasibility among key stakeholders. This may, in turn, significantly improve its availability, uptake, and sustainability
    • …
    corecore