Toroidal Constraints for Two-Point Localization Under High Outlier Ratios

2017 ◽  
Author(s):  
Federico Camposeco ◽  
Torsten Sattler ◽  
Andrea Cohen ◽  
Andreas Geiger ◽  
Marc Pollefeys
Keyword(s):  
High Outlier

scholarly journals Robustness Can Be Cheap: A Highly Efficient Approach to Discover Outliers under High Outlier Ratios

2019 ◽  
Vol 33 ◽  
pp. 5313-5320
Author(s):  
Siqi Wang ◽  
En Zhu ◽  
Xiping Hu ◽  
Xinwang Liu ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Computational Cost ◽  
Solution Process ◽  
Closed Form Solution ◽  
Form Solution ◽  
Low Rank ◽  
Alternative Formulation ◽  
Efficient Detection ◽  
Comparable Performance ◽  
High Space ◽  
High Outlier

Efficient detection of outliers from massive data with a high outlier ratio is challenging but not explicitly discussed yet. In such a case, existing methods either suffer from poor robustness or require expensive computations. This paper proposes a Low-rank based Efficient Outlier Detection (LEOD) framework to achieve favorable robustness against high outlier ratios with much cheaper computations. Specifically, it is worth highlighting the following aspects of LEOD: (1) Our framework exploits the low-rank structure embedded in the similarity matrix and considers inliers/outliers equally based on this low-rank structure, which facilitates us to encourage satisfying robustness with low computational cost later; (2) A novel re-weighting algorithm is derived as a new general solution to the constrained eigenvalue problem, which is a major bottleneck for the optimization process. Instead of the high space and time complexity (O((2n)2)/O((2n)3)) required by the classic solution, our algorithm enjoys O(n) space complexity and a faster optimization speed in the experiments; (3) A new alternative formulation is proposed for further acceleration of the solution process, where a cheap closed-form solution can be obtained. Experiments show that LEOD achieves strong robustness under an outlier ratio from 20% to 60%, while it is at most 100 times more memory efficient and 1000 times faster than its previous counterpart that attains comparable performance. The codes of LEOD are publicly available at https://github.com/demonzyj56/LEOD.

scholarly journals The association of the number of comorbidities and complications with length of stay, hospital mortality and LOS high outlier, based on administrative data

2008 ◽  
Vol 13 (3) ◽  
pp. 130-137 ◽  
Author(s):  
Kazuaki Kuwabara ◽  
Yuichi Imanaka ◽  
Shinya Matsuda ◽  
Kiyohide Fushimi ◽  
Hideki Hashimoto ◽  
...  
Keyword(s):  
Length Of Stay ◽  
Hospital Mortality ◽  
Administrative Data ◽  
Stay Hospital ◽  
High Outlier

scholarly journals Risk-Adjusted Pathologic Margin Positivity Rate As a Quality Indicator in Rectal Cancer Surgery

2014 ◽  
Vol 32 (27) ◽  
pp. 2967-2974 ◽  
Author(s):  
Nader N. Massarweh ◽  
Chung-Yuan Hu ◽  
Y. Nancy You ◽  
Brian K. Bednarski ◽  
Miguel A. Rodriguez-Bigas ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Postoperative Mortality ◽  
Hospital Performance ◽  
Sphincter Preservation ◽  
Cancer Surgery ◽  
Rank Test ◽  
Rectal Cancer Surgery ◽  
Cancer Data ◽  
Risk Of Death ◽  
High Outlier

Purpose Margin positivity after rectal cancer resection is associated with poorer outcomes. We previously developed an instrument for calculating hospital risk-adjusted margin positivity rate (RAMP) that allows identification of performance-based outliers and may represent a rectal cancer surgery quality metric. Methods This was an observational cohort study of patients with rectal cancer within the National Cancer Data Base (2003 to 2005). Hospital performance was categorized as low outlier (better than expected), high outlier (worse than expected), or non-RAMP outlier using standard observed-to-expected methodology. The association between outlier status and overall risk of death at 5 years was evaluated using Cox shared frailty modeling. Results Among 32,354 patients with cancer (mean age, 63.8 ± 13.2 years; 56.7% male; 87.3% white) treated at 1,349 hospitals (4.9% high outlier, 0.7% low outlier), 5.6% of patients were treated at high outliers and 3.0% were treated at low outliers. Various structural (academic status and volume), process (pathologic nodal evaluation and neoadjuvant radiation therapy use), and outcome (sphincter preservation, readmission, and 30-day postoperative mortality) measures were significantly associated with outlier status. Five-year overall survival was better at low outliers (79.9%) compared with high outliers (64.9%) and nonoutliers (68.9%; log-rank test, P < .001). Risk of death was lower at low outliers compared with high outliers (hazard ratio [HR], 0.61; 95% CI, 0.50 to 0.75) and nonoutliers (HR, 0.69; 95% CI, 0.57 to 0.83). Risk of death was higher at high outliers compared with nonoutliers (HR, 1.12; 95% CI, 1.03 to 1.23). Conclusion Hospital RAMP outlier status is a rectal cancer surgery composite metric that reliably captures hospital quality across all levels of care and could be integrated into existing quality improvement initiatives for hospital performance.

An Effective Bundled Approach Reduces Surgical Site Infections in a High-Outlier Colorectal Unit

2018 ◽  
Vol 61 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Emre Gorgun ◽  
Ahmet Rencuzogullari ◽  
Volkan Ozben ◽  
Luca Stocchi ◽  
Thomas Fraser ◽  
...  
Keyword(s):  
Surgical Site Infections ◽  
High Outlier

Should classification as an ACS-NSQIP high outlier be used to direct hospital quality improvement efforts?

2018 ◽  
Vol 216 (2) ◽  
pp. 213-216
Author(s):  
Elise H. Lawson ◽  
Patricia L. Roberts ◽  
Todd D. Francone ◽  
Peter W. Marcello ◽  
Thomas E. Read ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Hospital Quality ◽  
Acs Nsqip ◽  
High Outlier

The effect of outliers on the perception of sound change

2010 ◽  
Vol 22 (2) ◽  
pp. 175-190 ◽  
Author(s):  
William Labov ◽  
Maciej Baranowski ◽  
Aaron Dinkin
Keyword(s):  
Sound Change ◽  
Acoustic Properties ◽  
Very High ◽  
High Outlier

AbstractThe role of outliers in vowel distributions is examined through an experiment that registers subjects' assessments of symmetrical and asymmetrical distributions. Subjects first scaled their subjective impressions of a series of six resynthesized tokens of the word bad ranging from low front to upper mid front. They were then asked to register on this scale their overall impressions of four series of five phrases including bad: low symmetrical, low with a very low outlier, high symmetrical, high with a very high outlier. Subjects show the capacity to integrate outliers into their overall assessments in a manner consistent with their acoustic properties. The effect of low outliers was significantly greater, reflecting the socially marked status of this form in the Philadelphia community.

scholarly journals 1348. Indirect Standardization to Improve Comparison of Children’s Hospitals’ Antimicrobial Use

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S685-S685
Author(s):  
Rachel Wattier ◽  
Cary Thurm ◽  
Ritu Banerjee ◽  
Ritu Banerjee ◽  
Adam Hersh
Keyword(s):  
Antimicrobial Agents ◽  
Diagnosis Related Groups ◽  
Case Mix ◽  
Antimicrobial Use ◽  
Children's Hospitals ◽  
Ratio Distribution ◽  
Children’S Hospitals ◽  
Days Of Therapy ◽  
Indirect Standardization ◽  
High Outlier

Abstract Background Antimicrobial use (AU) measured by days of therapy per 1000 patient-days (DOT/1000pd), the most established metric, varies widely between children’s hospitals despite robust adoption of antimicrobial stewardship. Differences in diagnoses and procedures (case mix) between hospitals are a source of AU variation not included in adjustment methods such as the Standardized Antimicrobial Administration Ratio. In this study, we evaluated an indirect standardization method to adjust children’s hospital AU for case mix. Methods This multicenter retrospective cohort study included 51 children’s hospitals participating in the Pediatric Health Information System database from 2016-2018. All inpatient, observation, and neonatal admissions were included, with a total of 2,558,948 discharges. Hospitalizations were grouped into 83 strata defined based on All Patients Refined Diagnosis Related Groups (APR-DRGs). Observed to expected (O:E) ratios were calculated by indirect standardization of mean antibiotic DOT per case, with expected values from 2016-2018 and observed values from 2018, and compared to DOT/1000pd. Outlier hospitals were defined by O:E z-scores corresponding to below 10th percentile (low outlier) and above 90th percentile (high outlier). Results Antibacterial DOT/1000pd ranged from 345 to 776 (2.2-fold variation from lowest to highest), whereas O:E ratios ranged from 0.8 to 1.14 (1.4-fold variation from lowest to highest) (Figure 1). O:E ratios were moderately correlated with DOT/1000pd (correlation estimate 0.45; 95% CI 0.19-0.64; p=0.0008). Three high outlier hospitals and 6 low outlier hospitals were identified. Examining hospitals with comparably high DOT/1000pd but discordant O:E ratios, differences could be explained by variation in both case mix and condition-specific AU within strata defined by APR-DRGs. Figure 1. Individual hospitals labeled on the X-axis, ordered by level of antibacterial DOT/1000pd (left axis), represented by bars. Diamonds represent O:E ratios derived by indirect standardization (right axis). Outlier hospitals (low and high) are highlighted in yellow. Dashed horizontal lines represent 10th percentile (lower) and 90th percentile (upper) limits of the O:E ratio distribution. Conclusion The observed variation in DOT/1000pd between hospitals is reduced when indirect standardization is applied to account for case mix differences. This approach can be adapted for more specific uses including clinical conditions, patient populations, or antimicrobial agents. Indirect standardization may enhance stewardship efforts by providing adjusted comparisons that incorporate case mix differences between hospitals. Disclosures All Authors: No reported disclosures

Sign in / Sign up

Export Citation Format

Share Document