scholarly journals Analysis of uncertainty in the surgical department: durations, requests and cancellations

2019 ◽  
Vol 43 (6) ◽  
pp. 706 ◽  
Author(s):  
Belinda Spratt ◽  
Erhan Kozan ◽  
Michael Sinnott
Keyword(s):  
Statistical Analysis ◽  
Total Duration ◽  
Analytical Techniques ◽  
Planning And Scheduling ◽  
Surgical Department ◽  
Modelling Uncertainty ◽  
Rate Dependent ◽  
Planning Staff ◽  
Log Normal ◽  
Surgical Duration

Objective Analytical techniques are being implemented with increasing frequency to improve the management of surgical departments and to ensure that decisions are well informed. Often these analytical techniques rely on the validity of underlying statistical assumptions, including those around choice of distribution when modelling uncertainty. The aim of the present study was to determine a set of suitable statistical distributions and provide recommendations to assist hospital planning staff, based on three full years of historical data. Methods Statistical analysis was performed to determine the most appropriate distributions and models in a variety of surgical contexts. Data from 2013 to 2015 were collected from the surgical department at a large Australian public hospital. Results A log-normal distribution approximation of the total duration of surgeries in an operating room is appropriate when considering probability of overtime. Surgical requests can be modelled as a Poisson process with rate dependent on urgency and day of the week. Individual cancellations could be modelled as Bernoulli trials, with the probability of patient-, staff- and resource-based cancellations provided herein. Conclusions The analysis presented herein can be used to ensure that assumptions surrounding planning and scheduling in the surgical department are valid. Understanding the stochasticity in the surgical department may result in the implementation of more realistic decision models. What is known about the topic? Many surgical departments rely on crude estimates and general intuition to predict surgical duration, surgical requests (both elective and non-elective) and cancellations. What does this paper add? This paper describes how statistical analysis can be performed to validate common assumptions surrounding surgical uncertainty. The paper also provides a set of recommended distributions and associated parameters that can be used to model uncertainty in a large public hospital’s surgical department. What are the implications for practitioners? The insights on surgical uncertainty provided here will prove valuable for administrative staff who want to incorporate uncertainty in their surgical planning and scheduling decisions.

scholarly journals Singular Structural Features on Humic Fractions in Solution: Statistical Analysis of Diverse Analytical Techniques Spectra

2010 ◽  
Vol 74 (1) ◽  
pp. 74-86 ◽  
Author(s):  
Roberto Baigorri ◽  
Marta Fuentes ◽  
Francisco J. González-Vila ◽  
José M. García-Mina
Keyword(s):  
Statistical Analysis ◽  
Analytical Techniques ◽  
Structural Features ◽  
Humic Fractions

scholarly journals Statistical Analysis of Natural Events in the United States

1991 ◽  
Vol 21 (2) ◽  
pp. 253-276 ◽  
Author(s):  
Charles Levi ◽  
Christian Partrat
Keyword(s):  
United States ◽  
Statistical Analysis ◽  
Negative Binomial ◽  
The United States ◽  
Normal Model ◽  
Chi Square ◽  
Expected Frequency ◽  
Kolmogorov Smirnov ◽  
Anderson Darling ◽  
Log Normal

AbstractA statistical analysis is performed on natural events which can produce important damages to insurers. The analysis is based on hurricanes which have been observed in the United States between 1954 et 1986.At first, independence between the number and the amount of the losses is examined. Different distributions (Poisson and negative binomial for frequency and exponential, Pareto and lognormal for severity) are tested. Along classical tests as chi-square, Kolmogorov-Smirnov and non parametric tests, a test with weights on the upper tail of the distribution is used: the Anderson – Darling test.Confidence intervals for the probability of occurrence of a claim and expected frequency for different potential levels of claims are derived. The Poisson Log-normal model gives a very good fit to the data.

scholarly journals Towards Robustness in Neural Network Based Fault Diagnosis

2008 ◽  
Vol 18 (4) ◽  
pp. 443-454 ◽  
Author(s):  
Krzysztof Patan ◽  
Marcin Witczak ◽  
Józef Korbicz
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Fault Diagnosis ◽  
Soft Computing ◽  
Analytical Techniques ◽  
Industrial Applications ◽  
Nonlinear Behaviour ◽  
Design Problems ◽  
Modelling Uncertainty ◽  
Soft Computing Techniques

Towards Robustness in Neural Network Based Fault DiagnosisChallenging design problems arise regularly in modern fault diagnosis systems. Unfortunately, classical analytical techniques often cannot provide acceptable solutions to such difficult tasks. This explains why soft computing techniques such as neural networks become more and more popular in industrial applications of fault diagnosis. Taking into account the two crucial aspects, i.e., the nonlinear behaviour of the system being diagnosed as well as the robustness of a fault diagnosis scheme with respect to modelling uncertainty, two different neural network based schemes are described and carefully discussed. The final part of the paper presents an illustrative example regarding the modelling and fault diagnosis of a DC motor, which shows the performance of the proposed strategy.

Statistical Analysis of Pit Dimensions for Pre-Corroded AA 7075-T6

2014 ◽  
Vol 906 ◽  
pp. 259-262 ◽  
Author(s):  
Yong Fang Huang ◽  
Li Jie Chen ◽  
Xu Bin Ye
Keyword(s):  
Statistical Analysis ◽  
Fatigue Cracks ◽  
Gumbel Distribution ◽  
Fatigue Tests ◽  
Specimen Surface ◽  
Aa 7075 ◽  
Corrosion Pits ◽  
Log Normal ◽  
Aluminum Alloy 7075 ◽  
Log Normal Distribution

Aluminum alloy 7075-T6 specimens were corroded in 3.5% NaCl solution for 120 hours and 240 hours, respectively. Morphology and dimensions of corrosion pits on specimen surface were inspected with white light confocal profiler. Statistical analysis shows that pit dimensions can be fitted well with log-normal and Gumbel distribution. After surface inspections, we performed high-cycle fatigue tests for the specimens. Fracture analysis shows that fatigue cracks initiate from single pit or two adjacent pits, and the crack-initiation pit shape and dimensions were examined with SEM. It is found that initiation pit dimensions can be well described with the log-normal distribution. Additionally, initiation pit dimensions are significantly larger than those measured on specimen surface before fatigue tests.

scholarly journals An Approach to Temporal Planning and Scheduling in Domains with Predictable Exogenous Events

2006 ◽  
Vol 25 ◽  
pp. 187-231 ◽  
Author(s):  
A. Gerevini ◽  
A. Saetti ◽  
I. Serina
Keyword(s):  
Statistical Analysis ◽  
Time Windows ◽  
Temporal Reasoning ◽  
Temporal Constraints ◽  
Planning And Scheduling ◽  
Temporal Planning ◽  
Cpu Time ◽  
Planning Framework ◽  
Extra Difficulty ◽  
International Planning

The treatment of exogenous events in planning is practically important in many real-world domains where the preconditions of certain plan actions are affected by such events. In this paper we focus on planning in temporal domains with exogenous events that happen at known times, imposing the constraint that certain actions in the plan must be executed during some predefined time windows. When actions have durations, handling such temporal constraints adds an extra difficulty to planning. We propose an approach to planning in these domains which integrates constraint-based temporal reasoning into a graph-based planning framework using local search. Our techniques are implemented in a planner that took part in the 4th International Planning Competition (IPC-4). A statistical analysis of the results of IPC-4 demonstrates the effectiveness of our approach in terms of both CPU-time and plan quality. Additional experiments show the good performance of the temporal reasoning techniques integrated into our planner.

scholarly journals The Effect of Placement and Career Development on Employee Performance of PT. Mandiri Karya in Jakarta

2020 ◽  
Vol 10 (1) ◽  
pp. 183
Author(s):  
Ade Muslimat
Keyword(s):  
Statistical Analysis ◽  
Career Development ◽  
Hypothesis Testing ◽  
Employee Performance ◽  
Hypothesis Test ◽  
Analytical Techniques ◽  
Regression Testing ◽  
Career Placement

This study aims to determine the effect of career placement and development on employee performance at PT. Mandiri Karya in Jakarta. The method used is explanatory research with analytical techniques using statistical analysis with regression testing, correlation, determination and hypothesis testing. The results of this study the placement of a significant effect on employee performance by 41.6%, the hypothesis test obtained t count> t table or (8,133> 1,986). Career development has a significant effect on employee performance by 43.8%, the hypothesis test is obtained t count> t table or (8.508> 1.986). Career placement and development simultaneously have a significant effect on employee performance by 52.6%, the hypothesis test is obtained F count> F table or (51.106> 2,700).

Geospatial clustering of childhood IgA vasculitis and IgA vasculitis-associated nephritis

2020 ◽  
pp. annrheumdis-2020-218649
Author(s):  
Matej Sapina ◽  
Marijan Frkovic ◽  
Mario Sestan ◽  
Sasa Srsen ◽  
Aleksandar Ovuka ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Spatial Variability ◽  
Spatial Autocorrelation ◽  
Census Data ◽  
Analytical Techniques ◽  
Danube River ◽  
University Hospital ◽  
Iga Vasculitis ◽  
Spatial Statistical Analysis ◽  
Continental Part

ObjectivesResearch on spatial variability of the incidence of IgA vasculitis (IgAV) in children and its potential implications for elucidation of the multifactorial aetiology and pathogenesis is limited. We intended to observe spatial variability of the incidence of IgAV and IgA vasculitis-associated nephritis (IgAVN) using modern geostatistical methods, and hypothesised that their spatial distribution may be spatially clustered.MethodsPatients' data were retrospectively collected from 2009 to 2019 in five Croatian University Hospital Centres for paediatric rheumatology, and census data were used to calculate the incidence of IgAV. Using spatial empirical Bayesian smoothing, local Morans’ I and local indicator of spatial autocorrelation (LISA), we performed spatial statistical analysis.Results596 children diagnosed with IgAV were included in this study, of which 313 (52.52%) were male. The average annual incidence proportion was estimated to be 6.79 per 100 000 children, and the prevalence of IgAVN was 19.6%. Existence of spatial autocorrelation was observed in both IgAV and IgAVN; however, clustering distribution differed. While IgAV showed clustering in Mediterranean and west continental part around cities, IgAVN was clustered in the northern Mediterranean and eastern continental part, where a linear cluster following the Drava and Danube river was observed.ConclusionIgAV incidence in Croatia is similar to other European countries. Spatial statistical analysis showed a non-random distribution of IgAV and IgAVN. Although aetiological associations cannot be inferred, spatial analytical techniques may help in investigating and generating new hypotheses in non-communicable diseases considering possible environmental risk factors and identification of potential genetic or epigenetic diversity.

scholarly journals Effectiveness of Maitland Techniques in Idiopathic Shoulder Adhesive Capsulitis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Abhay Kumar ◽  
Suraj Kumar ◽  
Anoop Aggarwal ◽  
Ratnesh Kumar ◽  
Pooja Ghosh Das
Keyword(s):  
Statistical Analysis ◽  
External Rotation ◽  
Treatment Plan ◽  
Adhesive Capsulitis ◽  
Total Duration ◽  
Shoulder Function ◽  
Group Comparison ◽  
Before And After ◽  
Group A ◽  
Group B

Objective. To study the effectiveness of Maitland techniques in the treatment of idiopathic shoulder adhesive capsulitis. Methods. total of 40 patients diagnosed with idiopathic shoulder adhesive capsulitis were recruited and randomly allocated into two groups. In Group A () subjects were treated with Maitland mobilization technique and common supervised exercises, whereas subjects in Group B () only received common supervised exercises. Variables. Shoulder pain and disability index (SPADI), VAS and shoulder ROM (external rotation and abduction) were variables of the study. These were recorded before and after the session of the training. Total duration of the study was four weeks. Result. Statistical analysis of the data revealed that within-group comparison both groups showed significant improvement for all the parameters, whereas between-group comparison revealed higher improvement in Group A compared to the Group B. Conclusion. The study confirmed that addition of the Maitland mobilization technique with the combination of exercises have proved their efficacy in relieving pain and improving R.O.M. and shoulder function and hence should form a part of the treatment plan.

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