STATISTICAL METHODS FOR MEASUREMENT AND ANALYSIS IN TWO-PHASE PLOW

Author(s):  
Owen C. Jones Jr. ◽  
Novak Zuber
2006 ◽  
Vol 77 (10) ◽  
pp. 105103 ◽  
Author(s):  
Elvis E. Dominguez-Ontiveros ◽  
Carlos E. Estrada-Perez ◽  
Javier Ortiz-Villafuerte ◽  
Yassin A. Hassan

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e22509-e22509
Author(s):  
Christian Kappeler ◽  
Andrea Wagner ◽  
Joachim Kalmus ◽  
Marcia S. Brose ◽  
Martin Schlumberger ◽  
...  

e22509 Background: In controlled trials that allow patients to crossover from placebo (PBO) to active treatment (ACT) after progression, OS in PBO patients is confounded by ACT. Statistical methods to adjust OS for crossover rely on an assumption of common treatment effect (i.e. PBO to ACT crossover after progression has the same impact as ACT started at randomization). This exploratory analysis of two phase 3 trials (PBO-controlled and allowing crossover) with regorafenib in GIST and sorafenib in thyroid cancer provides evidence to support this assumption. Methods: Target lesions were assessed at baseline and at regular intervals post baseline. Progression-free survival (PFS) was assessed during double-blind (DB) treatment and secondary PFS (SPFS) in PBO patients during open-label (OL) treatment. Changes in target lesion diameter over time were estimated by a parametric model. Early tumor growth rate (TGR), defined as percent change from baseline/month in the sum of target lesion diameters, was calculated as the model curve slope at earliest time on the TGR curve. Results: SPFS during OL in PBO patients is closer to DB PFS in ACT patients than to DB PFS in PBO patients (Table). Early TGR during OL in PBO patients is closer to DB early TGR in ACT patients than to DB early TGR in PBO patients. Conclusions: Currently available statistical methods to adjust for the impact of treatment crossover are supported by clinical results from two independent randomized, controlled phase 3 studies. These results provide validity to crossover correction analyses. Clinical trial information: NCT01271712; NCT00984282. [Table: see text]


2021 ◽  
Vol 8 (2) ◽  
pp. 1-5
Author(s):  
Jay N Shah

Publication metrics indicate the visibility and reach of a research publication. The metrics can be at article-level, author-level, and journal-level to measure the scholarly output and its impact. Bibliometrics is the use of statistical methods to analyze various publications mostly used in the field of library and information science; whereas, scientometrics is the sub-field concerned with the science of metrics for the measurement and analysis of scholarly publications. Readers are not always well informed about the various publication metrics, and use them without knowing how to interpret them, their strength and limitations.


1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.


Author(s):  
K. P. Staudhammer ◽  
L. E. Murr

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.


Author(s):  
M.G. Burke ◽  
M.K. Miller

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.


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