913 research outputs found

    EVALUATING FORECASTS OF DISCRETE VARIABLES: PREDICTING CATTLE QUALITY GRADES

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    Little research has been conducted on evaluating out-of-sample forecasts of limited dependent variables. This study describes the large and small sample properties of two forecast evaluation techniques for limited dependent variables: receiver-operator curves and out-of-sample-log-likelihood functions. The methods are shown to provide identical model rankings in large samples and similar rankings in small samples. The likelihood function method is slightly better at detecting forecast accuracy in small samples, while receiver-operator curves are better at comparing forecasts across different data. By improving forecasts of fed-cattle quality grades, the forecast evaluation methods are shown to increase cattle marketing revenues by $2.59/head.Marketing,

    FORECASTING LIMITED DEPENDENT VARIABLES: BETTER STATISTICS FOR BETTER STEAKS

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    Little research has been conducted on evaluating out-of-sample forecasts of limited dependent variables. This study describes the large and small sample properties of two forecast evaluation techniques for limited dependent variables: receiver-operator curves and out-of-sample-log-likelihood functions. The methods are shown to provide identical model rankings in large samples and similar rankings in small samples. The likelihood function method is slightly better at detecting forecast accuracy in small samples, while receiver-operator curves are better at comparing forecasts across different data. By improving forecasts of fed-cattle quality grades, the forecast evaluation methods are shown to increase cattle marketing revenues by $2.59/head.Research Methods/ Statistical Methods,

    Study of low-cost fabrication of ablative heat shields

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    The major objectives were accomplished in three tasks: (1) modification of the ablative material composition for ease of fabrication as well as thermal and mechanical performance; (2) scaled-up, simplified, manufacturing techniques which resulted in cost reductions; and (3) the identification of a significant design problem caused by the differential pressure buildup imposed on mechanically attached ablative heat shield panels during launch

    System remotely inspects, measures, and records internal irregularities in piping

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    Video electromechanical probe visually inspects and measures internal offset and peaking of welds in relatively large piping. Irregularity dimensions are recorded on peripheral equipment consisting of video tape and X-Y plotter. The probe is used for inspection of vacuum-jacketed liquid lines that cannot be inspected externally

    Advanced stratified charge rotary aircraft engine design study

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    A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage

    Effect of Insulin Glargine Up-titration vs Insulin Degludec/Liraglutide on Glycated Hemoglobin Levels in Patients With Uncontrolled Type 2 Diabetes: The DUAL V Randomized Clinical Trial

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    Achieving glycemic control remains a challenge for patients with type 2 diabetes, even with insulin therapy. To assess whether a fixed ratio of insulin degludec/liraglutide was noninferior to continued titration of insulin glargine in patients with uncontrolled type 2 diabetes treated with insulin glargine and metformin. Phase 3, multinational, multicenter, 26-week, randomized, open-label, 2-group, treat-to-target trial conducted at 75 centers in 10 countries from September 2013 to November 2014 among 557 patients with uncontrolled diabetes treated with glargine (20-50 U) and metformin (≥1500 mg/d) with glycated hemoglobin (HbA1c) levels of 7% to 10% and a body mass index of 40 or lower. 1:1 randomization to degludec/liraglutide (n = 278; maximum dose, 50 U of degludec/1.8 mg of liraglutide) or glargine (n = 279; no maximum dose), with twice-weekly titration to a glucose target of 72 to 90 mg/dL. Primary outcome measure was change in HbA1c level after 26 weeks, with a noninferiority margin of 0.3% (upper bound of 95% CI, <0.3%). If noninferiority of degludec/liraglutide was achieved, secondary end points were tested for statistical superiority and included change in HbA1c level, change in body weight, and rate of confirmed hypoglycemic episodes. Among 557 randomized patients (mean: age, 58.8 years; women, 49.7%), 92.5% of patients completed the trial and provided data at 26 weeks. Baseline HbA1c level was 8.4% for the degludec/liraglutide group and 8.2% for the glargine group. HbA1c level reduction was greater with degludec/liraglutide vs glargine (-1.81% for the degludec/liraglutide group vs -1.13% for the glargine group; estimated treatment difference [ETD], -0.59% [95% CI, -0.74% to -0.45%]), meeting criteria for noninferiority (P < .001), and also meeting criteria for statistical superiority (P < .001). Treatment with degludec/liraglutide was also associated with weight loss compared with weight gain with glargine (-1.4 kg for degludec/liraglutide vs 1.8 kg for glargine; ETD, -3.20 kg [95% CI, -3.77 to -2.64],P < .001) and fewer confirmed hypoglycemic episodes (episodes/patient-year exposure, 2.23 for degludec/liraglutide vs 5.05 for glargine; estimated rate ratio, 0.43 [95% CI, 0.30 to 0.61],P < .001). Overall and serious adverse event rates were similar in the 2 groups, except for more nonserious gastrointestinal adverse events reported with degludec/liraglutide (adverse events, 79 for degludec/liraglutide vs 18 for glargine). Among patients with uncontrolled type 2 diabetes taking glargine and metformin, treatment with degludec/liraglutide compared with up-titration of glargine resulted in noninferior HbA1c levels, with secondary analyses indicating greater HbA1c level reduction after 26 weeks of treatment. Further studies are needed to assess longer-term efficacy and safety. clinicaltrials.gov Identifier: NCT01952145

    Brief Engagement and Acceptance Coaching for Hospice Settings (the BEACHeS study): Results from a Phase I study of acceptability and initial effectiveness in people with non-curative cancer.

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    Objectives: Transitioning into palliative care is psychologically demanding for people with advanced cancer, and there is a need for acceptable and effective interventions to support this. We aimed to develop and pilot test a brief Acceptance and Commitment Therapy (ACT) based intervention to improve quality of life and distress. Methods: Our mixed-method design included: (i) quantitative effectiveness testing using Single Case Experimental Design (SCED), (ii) qualitative interviews with participants, and (iii) focus groups with hospice staff. The five-session, in-person intervention was delivered to 10 participants; five completed at least 80%. Results: At baseline, participants reported poor quality of life but low distress. Most experienced substantial physical health deterioration during the study. SCED analysis methods did not show conclusively significant effects, but there was some indication that outcome improvement followed changes in expected intervention processes variables. Quantitative and qualitative data together demonstrates acceptability, perceived effectiveness and safety of the intervention. Qualitative interviews and focus groups were also used to gain feedback on intervention content and to make design recommendations to maximise success of later feasibility trials. Conclusions: This study adds to the growing evidence base for ACT in people with advanced cancer. A number of potential intervention mechanisms, for example a distress-buffering hypothesis, are raised by our data and these should be addressed in future research using randomised controlled trial designs. Our methodological recommendations—including recruiting non-cancer diagnoses, and earlier in the treatment trajectory—likely apply more broadly to the delivery of psychological intervention in the palliative care setting

    Model selection for discrete dependent variables: Better statistics for better steaks

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    Little research has been conducted on evaluating out-of-sample forecasts of discrete dependent variables. This study describes the large and small sample properties of two forecast evaluation techniques for discrete dependent variables: receiver-operator curves and out-of-sample log-likelihood functions. The methods are shown to provide identical model rankings in large samples and similar rankings in small samples. The likelihood function method is better at detecting forecast accuracy in small samples. By improving forecasts of fed cattle quality grades, the forecast evaluation methods are shown to increase cattle marketing revenues by $2.59/head.Peer reviewedAgricultural Economic
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