Random Subset of an n-Set (RANSUB)

1978 ◽  
pp. 23-25
Author(s):  
ALBERT NIJENHUIS ◽  
HERBERT S. WILF
Keyword(s):  
Random Subset

scholarly journals Non-contrast MRI can accurately characterize adnexal masses: a retrospective study

2021 ◽  
Author(s):  
Hilal Sahin ◽  
Camilla Panico ◽  
Stephan Ursprung ◽  
Vittorio Simeon ◽  
Paolo Chiodini ◽  
...  
Keyword(s):  
Contrast Medium ◽  
High Accuracy ◽  
Receiver Operating Curve ◽  
Intravenous Contrast ◽  
Random Subset ◽  
Adnexal Masses ◽  
Intravenous Contrast Medium ◽  
Mri Protocol ◽  
Malignant Lesions ◽  
Mri Score

Abstract Objective To determine the accuracy of interpretation of a non-contrast MRI protocol in characterizing adnexal masses. Methods and materials Two hundred ninety-one patients (350 adnexal masses) who underwent gynecological MRI at our institution between the 1st of January 2008 and the 31st of December 2018 were reviewed. A random subset (102 patients with 121 masses) was chosen to evaluate the reproducibility and repeatability of readers’ assessments. Readers evaluated non-contrast MRI scans retrospectively, assigned a 5-point score for the risk of malignancy and gave a specific diagnosis. The reference standard for the diagnosis was histopathology or at least one-year imaging follow-up. Diagnostic accuracy of the non-contrast MRI score was calculated. Inter- and intra-reader agreement was analyzed with Cohen’s kappa statistics. Results There were 53/350 (15.1%) malignant lesions in the whole cohort and 20/121 (16.5%) malignant lesions in the random subset. Good agreement between readers was found for the non-contrast MRI score (к = 0.73, 95% confidence interval [CI] 0.58–0.86) whilst the intra-reader agreement was excellent (к = 0.81, 95% CI 0.70–0.88). The non-contrast MRI score value of ≥ 4 was associated with malignancy with a sensitivity of 84.9%, a specificity of 95.9%, an accuracy of 94.2% and a positive likelihood ratio of 21 (area under the receiver operating curve 0.93, 95% CI 0.90–0.96). Conclusion Adnexal mass characterization on MRI without the administration of contrast medium has a high accuracy and excellent inter- and intra-reader agreement. Our results suggest that non-contrast studies may offer a reasonable diagnostic alternative when the administration of intravenous contrast medium is not possible. Key Points • A non-contrast pelvic MRI protocol may allow the characterization of adnexal masses with high accuracy. • The non-contrast MRI score may be used in clinical practice for differentiating benign from malignant adnexal lesions when the lack of intravenous contrast medium precludes analysis with the O–RADS MRI score.

scholarly journals Usability Evaluation of Slanted Computer Mice

2021 ◽  
Vol 18 (8) ◽  
pp. 3854
Author(s):  
Miguel L. Lourenço ◽  
Fátima Lanhoso ◽  
Denis A. Coelho
Keyword(s):  
Ease Of Use ◽  
Perceived Ease Of Use ◽  
Slant Angle ◽  
Mean Values ◽  
Random Subset ◽  
Hand Size ◽  
Preference Rank ◽  
Size Groups ◽  
Subjective Usability ◽  
Conventional Device

Prevention of musculoskeletal disorders is supported by use of slanted rather than horizontal pointing devices, but user acceptance of the former may be compromised due to lower perceived ease of use. This study compares subjectively rated usability (N = 37) for three sizes of slanted computer mice and includes a horizontal small conventional device as a reference. For a random subset of the sample (n = 10), objective usability parameters were also elicited. Participants followed a standard protocol which is based on executing graphical pointing, steering, and dragging tasks generated by a purpose-built software. Subjective ratings were collected for each of the four pointing devices tested. The three slanted devices differed in size but were chosen because of an approximately similar slant angle (around 50–60 degrees relative to the horizontal plane). Additionally, effectiveness and efficiency were objectively calculated based on data recorded for the graphical tasks’ software for a random subset of the participants (n = 10). The results unveil small differences in preference in some of the subjective usability parameters across hand size groups. This notwithstanding, the objective efficiency results are aligned with the subjective results, indicating consistency with the hypothesis that smaller slanted devices relative to the user’s hand size are easier to use than larger ones. Mean values of weighted efficiency recorded in the study range from 68% to 75%, with differences across devices coherent with preference rank orders.

scholarly journals Threatened birds of Guatemala: a random subset of the avifauna?

2011 ◽  
Vol 22 (3) ◽  
pp. 348-353
Author(s):  
ANDREA NÁJERA ◽  
JAVIER A. SIMONETTI
Keyword(s):  
Body Size ◽  
Geographical Distribution ◽  
Scientific Information ◽  
Bird Species ◽  
Critically Endangered ◽  
Aquatic Species ◽  
Random Subset ◽  
The Pacific ◽  
Taxonomic Affiliation

SummaryIdentifying attributes that affect the vulnerability of a species to extinction is important as it allows conservation efforts to be focused on more susceptible species. We assessed whether threatened birds of Guatemala are a random subset of the avifauna, considering their taxonomic affiliation, body size, diet and geographical distribution. We found that threatened bird species in Guatemala were neither taxonomically nor geographically randomly distributed. Large-bodied species and Psittaciformes, Galliformes, Falconiformes and Ciconiformes were among the most threatened groups, and the Pacific slopes of the country hosted more threatened birds than would be expected. Published scientific information regarding Critically Endangered bird species in Guatemala is scant and biased against nocturnal and aquatic species. Research and conservation efforts ought to be oriented toward these species and regions to safeguard the Guatemalan avifauna. This study allows an overall consideration on whether we are conserving the species and areas that are important for threatened birds.

Random subset feature selection for ecological niche models of wildfire activity in Western North America

2018 ◽  
Vol 383 ◽  
pp. 52-68 ◽  
Author(s):  
James L. Tracy ◽  
Antonio Trabucco ◽  
A. Michelle Lawing ◽  
J. Tomasz Giermakowski ◽  
Maria Tchakerian ◽  
...  
Keyword(s):  
Feature Selection ◽  
North America ◽  
Ecological Niche ◽  
Western North America ◽  
Ecological Niche Models ◽  
Random Subset ◽  
Selection For ◽  
Niche Models

Adaptive Hybrid Semantic Selection of SAWSDL Services with SAWSDL-MX2

2010 ◽  
Vol 6 (4) ◽  
pp. 1-26 ◽  
Author(s):  
Matthias Klusch ◽  
Patrick Kapahnke ◽  
Ingo Zinnikus
Keyword(s):  
Support Vector Machine ◽  
Comparative Evaluation ◽  
Structural Similarity ◽  
Support Vector ◽  
Test Collection ◽  
Semantic Matching ◽  
Retrieval Performance ◽  
Text Similarity ◽  
Random Subset ◽  
Selection Of

In this paper, the authors present an adaptive, hybrid semantic matchmaker for SAWSDL services, called SAWSDL-MX2. It determines three types of semantic matching of an advertised service with a requested one, which are described in standard SAWSDL: logic-based, text-similarity-based and XML-tree edit-based structural similarity. Before selection, SAWSDL-MX2 learns the optimal aggregation of these different matching degrees off-line over a random subset of a given SAWSDL service retrieval test collection by exploiting a binary support vector machine-based classifier with ranking. The authors present a comparative evaluation of the retrieval performance of SAWSDL-MX2.

Stochastic Models of Queue Storage

1988 ◽  
Vol 2 (1) ◽  
pp. 75-93 ◽  
Author(s):  
E. G. Coffman ◽  
L. Flatto ◽  
I. Mitrani ◽  
L. A. Shepp ◽  
C. Knessl
Keyword(s):  
Stochastic Models ◽  
Random Variables ◽  
Single Units ◽  
Random Subset ◽  
Processing Times ◽  
Poisson Stream

We study a model of queue storage in which items (requests for single units of storage) arrive in a Poisson stream and are accommodated by the first available location in a linear scan of storage. The processing times of items are independent, exponentially distributed random variables. The set of occupied locations (identified by their indices) at time t forms a random subset Si, of [1,2,.…]. The extent of the fragmentation in Si, i.e., the alternating holes and occupied regions of storage, is measured by Wt, = max St, – |St|.

Allocation of Attention to Visual and Nonvisual Perceptual Channels by Marksmen During Aiming: Skill-Level Differences

2019 ◽  
Vol 41 (6) ◽  
pp. 386-400
Author(s):  
Shamsi S. Monfared ◽  
Gershon Tenenbaum ◽  
Jonathan R. Folstein ◽  
K. Anders Ericsson
Keyword(s):  
Analysis Of Variance ◽  
Skill Level ◽  
Factorial Analysis ◽  
Attention Allocation ◽  
Verbal Reports ◽  
Skill Levels ◽  
Random Subset ◽  
Vision Condition ◽  
Actual Location ◽  
Expert To Novice

This study examined attention allocation in 30 marksmen categorized into 3 skill levels ranging from expert to novice. Each shooter performed 336 shooting trials. Half of the trials were performed under an occluded-vision condition and the rest under regular, unoccluded conditions. Immediately after completion of a random subset of shots (96 trials), shooters estimated the actual location of each shot, and on a random subset of trials (48 trials), shooters gave retrospective verbal reports. A mixed 3 × 2 factorial analysis of variance revealed that the expert marksmen performed and estimated their shots more accurately than the intermediate and novice marksmen, the intermediates performed like the experts under the full-vision condition and like novices under the occluded-vision condition, and the experts reported attending more to nonvisual information while they estimated their shots than did the novices. The findings advance our understanding of the mechanisms mediating expertise.

The coupon subset collection problem

2001 ◽  
Vol 38 (03) ◽  
pp. 737-746 ◽  
Author(s):  
Ilan Adler ◽  
Sheldon M. Ross
Keyword(s):  
Expected Number ◽  
Random Subset ◽  
Reliability Problem ◽  
Efficient Simulation ◽  
Time Point

The coupon subset collection problem is a generalization of the classical coupon collecting problem, in that rather than collecting individual coupons we obtain, at each time point, a random subset of coupons. The problem of interest is to determine the expected number of subsets needed until each coupon is contained in at least one of these subsets. We provide bounds on this number, give efficient simulation procedures for estimating it, and then apply our results to a reliability problem.

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