A Novel Approach for Analyzing Single Buffer Queueing Systems with State-Dependent Vacation and Correlated Input Process under Four Different Service Disciplines

2015 ◽  
Vol 6 (3) ◽  
pp. 19-59 ◽  
Author(s):  
Thomas Yew Sing Lee
Keyword(s):  
Performance Measures ◽  
Probability Generating Function ◽  
Performance Measure ◽  
Idle Time ◽  
Separate Analysis ◽  
Input Process ◽  
State Dependent ◽  
Special Cases ◽  
Service Disciplines ◽  
Different Types

The author presents performance analysis of a single buffer multiple-queue system. Four different types of service disciplines (i.e., non-preemptive, pre-emptive repeat different, state dependent random polling and globally gated) are analyzed. His model includes correlated input process and three different types of non-productive time (i.e., switchover, vacation and idle time). Special cases of the model includes server with mixed multiple and single vacations, stopping server with delayed vacation and stopping server with alternating vacation and idle time. For each of the four service disciplines the key performance measures such as average customer waiting time, loss probability, and throughput are computed. The results permit a detailed discussion of how these performance measures depends on the customer arrival rate, the customer service time, the switchover time, the vacation time, and the idle time. Moreover, extensive numerical results are presented and the four service disciplines are compared with respect to the performance measure. Previous studies of the single buffer multiple-queue systems tend to provide separate analysis for the two cases of zero and nonzero switchover time. The author is able to provide a unified analysis for the two cases. His results generalize and improve a number of known results on single buffer multiple-queue systems. Furthermore, this method does not require differentiation while it is needed if one uses the probability generating function approach. Lastly, the author's approach works for all single buffer multiple-queue systems in which the next queue to be served is determines solely on the basis of the occupancy states at the end of the cycle time.

Deriving Performance Measures for Team Tasks: Evaluating a Methodology

1989 ◽  
Vol 33 (19) ◽  
pp. 1273-1277
Author(s):  
Joyce Hogan ◽  
Rainer M. Neubauer ◽  
Eduardo Salas
Keyword(s):  
Performance Measures ◽  
Team Performance ◽  
Performance Measure ◽  
Task Type ◽  
Performance Rating ◽  
Factor Analyses ◽  
Team Task ◽  
Different Types ◽  
Team Evaluation ◽  
Performance Conditions

This study investigates the usefulness of existing performance measures for evaluating the outcome effectiveness of team tasks. It describes a method to identify the measures most appropriate for evaluating training on different types of tasks and under different performance conditions. Six prototype team tasks served as rating stimuli that were used to evaluate 15 objective and 23 subjective team performance measures. Raters (N=33) assessed the usefulness of these performance measures for evaluating performance on each team task under three different scenarios. These scenarios asked how useful the measure would be for: (1) evaluating the performance of teams that want to improve and develop skills; (2) evaluating the performance of teams that have learned the task and need to maintain performance; and (3) helping a consultant to appraise the performance of the team. Results indicated reliable panel ratings; factor analyses of each objective and subjective performance measure correlation matrix revealed five-factor solutions for each domain, and these solutions were consistent across tasks and scenarios. Performance rating means varied significantly by task type, but generally were consistent across scenarios. The ratings are sensitive to task type and can be used systematically to specify relevant dimensions of team evaluation.

scholarly journals Computational Analysis of Queues with Catastrophes in a Multiphase Random Environment

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
G. Arul Freeda Vinodhini ◽  
V. Vidhya
Keyword(s):  
Performance Measures ◽  
Computational Analysis ◽  
Road Traffic ◽  
Probability Generating Function ◽  
Weather Conditions ◽  
Traffic Model ◽  
Matrix Geometric Method ◽  
Special Cases ◽  
Full Capacity ◽  
Steady State Probabilities

A dynamically changing road traffic model which occasionally suffers a disaster (traffic collision, wrecked vehicles, conflicting weather conditions, spilled cargo, and hazardous matter) resulting in loss of all the vehicles (diverted to other routes) has been discussed. Once the system gets repaired, it undergoesn-1trial phases and finally reaches its full capacity phasen. We have obtained the explicit steady state probabilities of the system via Matrix Geometric Method. Probability Generating Function is used to evaluate the time spent by the system in each phase. Various performance measures like mean traffic, average waiting time of vehicles, and fraction of vehicles lost are calculated. Some special cases have also been discussed.

scholarly journals Analysis of an M/M/cQueueing System with Impatient Customers and Synchronous Vacations

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Dequan Yue ◽  
Wuyi Yue ◽  
Guoxi Zhao
Keyword(s):  
Steady State ◽  
Performance Measures ◽  
Function Method ◽  
Queueing System ◽  
Probability Generating Function ◽  
Impatient Customers ◽  
Balance Equations ◽  
Limiting Behavior ◽  
Special Cases ◽  
Steady State Probabilities

We consider an M/M/cqueueing system with impatient customers and a synchronous vacation policy, where customer impatience is due to the servers’ vacation. Whenever a system becomes empty, all the servers take a vacation. If the system is still empty, when the vacation ends, all the servers take another vacation; otherwise, they return to serve the queue. We develop the balance equations for the steady-state probabilities and solve the equations by using the probability generating function method. We obtain explicit expressions of some important performance measures by means of the two indexes. Based on these, we obtain some results about limiting behavior for some performance measures. We derive closed-form expressions of some important performance measures for two special cases. Finally, some numerical results are also presented.

Effects of Accounting-Method Choices on Subjective Performance-Measure Weighting Decisions: Experimental Evidence on Precision and Error Covariance

2005 ◽  
Vol 80 (4) ◽  
pp. 1163-1192 ◽  
Author(s):  
Ranjani Krishnan ◽  
Joan L. Luft ◽  
Michael D. Shields
Keyword(s):  
Performance Measures ◽  
Error Variance ◽  
Spillover Effects ◽  
Performance Measure ◽  
Incentive System ◽  
Experimental Setting ◽  
Error Covariance ◽  
Psychology Theory ◽  
Optimal Weighting ◽  
Similarity And Difference

Performance-measure weights for incentive compensation are often determined subjectively. Determining these weights is a cognitively difficult task, and archival research shows that observed performance-measure weights are only partially consistent with the predictions of agency theory. Ittner et al. (2003) have concluded that psychology theory can help to explain such inconsistencies. In an experimental setting based on Feltham and Xie (1994), we use psychology theories of reasoning to predict distinctive patterns of similarity and difference between optimal and actual subjective performance-measure weights. The following predictions are supported. First, in contrast to a number of prior studies, most individuals' decisions are significantly influenced by the performance measures' error variance (precision) and error covariance. Second, directional errors in the use of these measurement attributes are relatively frequent, resulting in a mean underreaction to an accounting change that alters performance measurement error. Third, individuals seem insufficiently aware that a change in the accounting for one measure has spillover effects on the optimal weighting of the other measure in a two-measure incentive system. In consequence, they make performance-measure weighting decisions that are likely to result in misallocations of agent effort.

State-dependent signalling in queueing networks

1994 ◽  
Vol 26 (02) ◽  
pp. 436-455 ◽  
Author(s):  
W. Henderson ◽  
B. S. Northcote ◽  
P. G. Taylor
Keyword(s):  
Queueing Networks ◽  
State Dependence ◽  
Product Form ◽  
Batch Size ◽  
Single Server ◽  
Negative Customers ◽  
Affect Control ◽  
State Dependent ◽  
Special Cases ◽  
Equilibrium Distributions

It has recently been shown that networks of queues with state-dependent movement of negative customers, and with state-independent triggering of customer movement have product-form equilibrium distributions. Triggers and negative customers are entities which, when arriving to a queue, force a single customer to be routed through the network or leave the network respectively. They are ‘signals' which affect/control network behaviour. The provision of state-dependent intensities introduces queues other than single-server queues into the network. This paper considers networks with state-dependent intensities in which signals can be either a trigger or a batch of negative customers (the batch size being determined by an arbitrary probability distribution). It is shown that such networks still have a product-form equilibrium distribution. Natural methods for state space truncation and for the inclusion of multiple customer types in the network can be viewed as special cases of this state dependence. A further generalisation allows for the possibility of signals building up at nodes.

Abstract 3429: Implementation of Electronic Medical Record Stroke Templates Increases Compliance with Stroke Performance Measures

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Crismely A Perdomo ◽  
Vepuka E Kauari ◽  
Elizabeth Suarez ◽  
Olajide Williams ◽  
Joshua Stillman ◽  
...  
Keyword(s):  
Medical Record ◽  
Electronic Medical Record ◽  
Performance Measures ◽  
New York State ◽  
Stroke Care ◽  
Performance Measure ◽  
Performance Comparison ◽  
York State Department ◽  
Free Text ◽  
And Performance

Background and Purpose The literature demonstrates how utilizing evidence-based, standardized stroke care can improve patient outcomes; however, the contribution of electronic medical record (EMR) systems may also impact outcomes by ensuring utilization and compliance with established stroke performance measures, facilitating and improving documentation requirements, and standardizing approach to care. In 2008, documentation in patients’ medical records was done in combination of paper and a template free EMR. Originally, the EMR was used for order entry, then transitioned to full electronic documentation in 2009. At that time we implemented our stroke templates and performance measures based on regulatory standards. We hypothesized that the stroke template implementation would help us achieve performance measure criteria above state benchmarks as set out by the New York State Department of Health (NYS DOH). Methods Implementation was phased in [over 18 months], initially using a template that only included neurological assessment and free text fields for stroke measures. By July 2010, existing templates were modified and additional stroke templates were implemented to meet new regulatory requirements and meaningful use criteria. Retrospective data review was conducted for performance comparison between 2008 -- one year prior to EMR/template implementation -- and 2010. In Quarter 1 of 2011 EMR was also implemented in the Emergency Department (ED). Data was reviewed for compliance with stroke measures. Results Documentation compliance substantially improved between 2008 and Quarter 1 2011: Compliance for these measures has been maintained ≥ 85% since November 2010, ≥ 90% Q1 2011 Conclusions The EMR implementation of stroke templates and performance measures can produce substantial improvement in performance measure compliance. Future steps will include automated documentation alerts to retrieve information and real time discovery of missing documentation for concurrent quality review and improvement

A Tutorial on the Use of ROC Analysis for Computer-Aided Diagnostic Systems

2005 ◽  
Vol 27 (3) ◽  
pp. 181-198 ◽  
Author(s):  
Ulrich Scheipers ◽  
Christian Perrey ◽  
Stefan Siebers ◽  
Christian Hansen ◽  
Helmut Ermert
Keyword(s):  
Performance Measures ◽  
Roc Curve ◽  
Roc Analysis ◽  
Real Life ◽  
Performance Measure ◽  
Diagnostic Systems ◽  
Life Data ◽  
Separation Threshold ◽  
Real Life Data ◽  
Computer Aided

The application of the receiver operating characteristic (ROC) curve for computer-aided diagnostic systems is reviewed. A statistical framework is presented and different methods of evaluating the classification performance of computer-aided diagnostic systems, and, in particular, systems for ultrasonic tissue characterization, are derived. Most classifiers that are used today are dependent on a separation threshold, which can be chosen freely in many cases. The separation threshold separates the range of output values of the classification system into different target groups, thus conducting the actual classification process. In the first part of this paper, threshold specific performance measures, e.g., sensitivity and specificity; are presented. In the second part, a threshold-independent performance measure, the area under the ROC curve, is reviewed. Only the use of separation threshold-independent performance measures provides classification results that are overall representative for computer-aided diagnostic systems. The following text was motivated by the lack of a complete and definite discussion of the underlying subject in available textbooks, references and publications. Most manuscripts published so far address the theme of performance evaluation using ROC analysis in a manner too general to be practical for everyday use in the development of computer-aided diagnostic systems. Nowadays, the user of computer-aided diagnostic systems typically handles huge amounts of numerical data, not always distributed normally. Many assumptions made in more or less theoretical works on ROC analysis are no longer valid for real-life data. The paper aims at closing the gap between theoretical works and real-life data. The review provides the interested scientist with information needed to conduct ROC analysis and to integrate algorithms performing ROC analysis into classification systems while understanding the basic principles of classification.

scholarly journals Alternative shoe closure designs alter biomechanical performance during agility-based movements

2020 ◽  
Author(s):  
Moira Pryhoda ◽  
Rachel Wathen ◽  
Jay Dicharry ◽  
Kevin Shelburne ◽  
Bradley Davidson
Keyword(s):  
Mechanical Properties ◽  
Performance Measures ◽  
Performance Measure ◽  
Male Athletes ◽  
Impaired Performance ◽  
Performance Improvements ◽  
Two Measures ◽  
Ground Contact Time ◽  
Improved Performance ◽  
Consistent Performance

The objective of this research was to determine if three alternative shoe upper closures improve biomechanical performance measures relative to a standard lace closure in court-based movements. NCAA Division 1 and club-level male athletes recruited from lacrosse, soccer, tennis, and rugby performed four court-based movements: Lateral Skater Jump repeats (LSJ), Countermovement Jump repeats (CMJ), Triangle Drop Step drill (TDS), and Anterior-Posterior drill (AP). Each athlete performed the movements in four shoe upper closures: Standard Closure, Lace Replacement, Y Wrap, and Tri Strap. Ground contact time, peak eccentric rate of force development (RFD), peak concentric GRF, peak concentric COM power, eccentric work, concentric work, and movement completion time were measured. Tri Strap saw improvements in four of seven biomechanical variables during CMJ and LSJ and one variable during TDS. Lace Replacement delivered improvements in one performance measure during CMJ, LSJ, and AP, and two variables in TDS. Y Wrap improved performance in three performance measures during LSJ and impaired performance in two measures during CMJ and three measures during AP. Tri Strap provided the most consistent performance improvements across all movements. This study allowed for the mechanical properties of the shoe lower to remain consistent across designs to examine if an alternative shoe upper closure could enhance performance. Our results indicate that increased proprioception and/or mechanical properties due to the alternative closures, especially Tri Strap, improves athlete performance, which concludes that the design of the shoe upper is an essential consideration in shoe design.

Abstract 038: American Heart Association Mission: Lifeline Breakthrough Series Collaborative Improving the Survival Rates for Out of Hospital Cardiac Arrest by Focusing on Early CPR With an Emphasis on Chest Compressions

2017 ◽  
Vol 10 (suppl_3) ◽  
Author(s):  
Charles R Siegel ◽  
Anjan Chakrabarti ◽  
Lewis Siegel ◽  
Forrest Winslow ◽  
Thomas Hall
Keyword(s):  
Cardiac Arrest ◽  
Quality Improvement ◽  
Performance Measures ◽  
Effective Diffusion ◽  
Survival Rates ◽  
Public Health Problem ◽  
Heart Association ◽  
Performance Measure ◽  
Compression Rate ◽  
Hospital Cardiac Arrest

Introduction: Out-of-hospital cardiac arrest (OHCA) remains a highly morbid public health problem. Despite improving practices and clear guidelines, mortality from this condition remains high at 90%, with survivors often suffering from poor neurologic outcomes. To determine the feasibility of quality improvement collaboratives to narrow gaps between evidence-based practice and patient care for OHCA, we conducted a pilot study of the AHA Resuscitation Collaborative. Methods: Eight emergency medical service agencies participated in the quality improvement collaborative pilot project. We identified several OHCA performance measures to assess the quality of care, guide collaborative activities, and monitor change in performance over time. Over the course of four learning sessions, participants were trained in quality improvement and performance measurement, analyzed performance measure results, and shared successes and challenges. Results: Five remaining agencies underwent the process outlined in Figure 1. Adherence to performance measures, including compression rate compliance (Figure 2), improved over the course of the collaborative. Compression rate compliance in Figure 2 corresponds to the process improvement efforts of the Chesapeake Fire Department with achievement of goals for optimal range of chest compression rate between 100 and 120 compressions per minute during resuscitations. Conclusion: As demonstrated in Virginia, the collaborative approach was an effective framework to improve OHCA care. Improvement in performance measures, the evident commitment of dedicated peers and colleagues, consistent collaboration, and the effective diffusion of best practices all support the continued use of this model.

Circles on the Complex Plane

2021 ◽  
pp. 3-12
Author(s):  
A. Girsh
Keyword(s):  
Euclidean Space ◽  
Complex Plane ◽  
Euclidean Plane ◽  
Complex Space ◽  
Radical Center ◽  
Special Cases ◽  
Different Types ◽  
Different Dimensions ◽  
The Given ◽  
Made In

The Euclidean plane and Euclidean space themselves do not contain imaginary elements by definition, but are inextricably linked with them through special cases, and this leads to the need to propagate geometry into the area of imaginary values. Such propagation, that is adding a plane or space, a field of imaginary coordinates to the field of real coordinates leads to various variants of spaces of different dimensions, depending on the given axiomatics. Earlier, in a number of papers, were shown examples for solving some urgent problems of geometry using imaginary geometric images [2, 9, 11, 13, 15]. In this paper are considered constructions of orthogonal and diametrical positions of circles on a complex plane. A generalization has been made of the proposition about a circle on the complex plane orthogonally intersecting three given spheres on the proposition about a sphere in the complex space orthogonally intersecting four given spheres. Studies have shown that the diametrical position of circles on the Euclidean E-plane is an attribute of the orthogonal position of the circles’ imaginary components on the pseudo-Euclidean M-plane. Real, imaginary and degenerated to a point circles have been involved in structures and considered, have been demonstrated these circles’ forms, properties and attributes of their orthogonal position. Has been presented the construction of radical axes and a radical center for circles of the same and different types. A propagation of 2D mutual orthogonal position of circles on 3D spheres has been made. In figures, dashed lines indicate imaginary elements.

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