scholarly journals Modeling Web Client and System Behavior

Information ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 337
Author(s):  
Tomasz Rak
Keyword(s):  
Performance Prediction ◽  
Production Systems ◽  
Performance Model ◽  
Enterprise Performance ◽  
Performance Models ◽  
Modeling Methodology ◽  
System Behaviour ◽  
Simulation Based ◽  
Significant Effort ◽  
Web Systems

Web systems are becoming more and more popular. An efficiently working network system is the basis for the functioning of every enterprise. Performance models are powerful tools for performance prediction. The creation of performance models requires significant effort. In the article, we want to present various performance models of customer and Web systems. In particular, we want to examine a system behaviour related to different flow routes of clients in the system. Therefore we propose Queueing Petri Nets, the new modeling methodology for dealing with performance issues of production systems. We follow the simulation-based approach. We consider 25 different models to check performance. Then we evaluate them based on the proposed metrics. The validation results show that the model is able to predict the performance with a relative error lower than 20%. Our evaluation shows that prepared models can reduce the effort of production system preparation. The resulting performance model can predict the system behaviour in a particular layer at the indicated load.

Validating Human Performance Models: Building a House without Bricks

2020 ◽  
Vol 64 (1) ◽  
pp. 1511-1514
Author(s):  
Richard Steinberg ◽  
Raytheon Company ◽  
Alice Diggs ◽  
Raytheon Company ◽  
Jade Driggs
Keyword(s):  
Air Force ◽  
Human Performance ◽  
Control Program ◽  
Real Data ◽  
Performance Model ◽  
Force Model ◽  
Performance Models ◽  
Actual System ◽  
Support Design ◽  
Trade Offs

Verification and validation (V&V) for human performance models (HPMs) can be likened to building a house with no bricks, since it is difficult to obtain metrics to validate a model when the system is still in development. HPMs are effective for performing trade-offs between the human system designs factors including number of operators needed, the role of automated tasks versus operator tasks, and member task responsibilities required to operate a system. On a recent government contract, our team used a human performance model to provide additional analysis beyond traditional trade studies. Our team verified the contractually mandated staff size for using the system. This task demanded that the model have sufficient fidelity to provide information for high confidence staffing decisions. It required a method for verifying and validating the model and its results to ensure that it accurately reflected the real world. The situation caused a dilemma because there was no actual system to gather real data to use to validate the model. It is a challenge to validate human performance models, since they support design decisions prior to system. For example, crew models are typically inform the design, staffing needs, and the requirements for each operator’s user interface prior to development. This paper discusses a successful case study for how our team met the V&V challenges with the US Air Force model accreditation authority and successfully accredited our human performance model with enough fidelity for requirements testing on an Air Force Command and Control program.

CPI Stress Induced Carrier Mobility Shift in Advanced Silicon Nodes

2016 ◽  
Author(s):  
Valeriy Sukharev ◽  
Jun-Ho Choy ◽  
Armen Kteyan ◽  
Henrik Hovsepyan ◽  
Uwe Muehle ◽  
...  
Keyword(s):  
Electrical Characterization ◽  
Compact Modeling ◽  
Electrical Characteristics ◽  
Mobility Shift ◽  
Physical Strain ◽  
Multi Scale ◽  
Modeling Methodology ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Final Design

Potential challenges with managing mechanical stress and the consequent effects on device performance for advanced 3D IC technologies are outlined. The growing need for a simulation-based design verification flow capable of analyzing and detecting across-die out-of-spec stress-induced variations in MOSFET/FinFET electrical characteristics is highlighted. A physics-based compact modeling methodology for multi-scale simulation of all contributing components of stress induced variability is described. A simulation flow that provides an interface between layout formats (GDS II, OASIS), and FEA-based package-scale tools, is also developed. This tool, can be used to optimize the floorplan for different circuits and packaging technologies, and/or for the final design signoff, for all stress induced phenomena. Finally, a calibration technique based on fitting to measured electrical characterization data is presented, along with correlation of the electrical characteristics to direct physical strain measurements.

Adaptive PPS durch simulationsbasierte Optimierung*/Adaptive PPC by simulation-based optimization

2017 ◽  
Vol 107 (04) ◽  
pp. 288-292
Author(s):  
M. Kück ◽  
J. Ehm ◽  
T. Hildebrandt ◽  
M. Prof. Freitag ◽  
E. M. Prof. Frazzon
Keyword(s):  
Job Shop ◽  
Job Shop Scheduling ◽  
Production Systems ◽  
Semiconductor Industry ◽  
Small Scale ◽  
Planning Problem ◽  
Optimization Approach ◽  
Flexible Production Systems ◽  
Simulation Based ◽  
Simulation Based Optimization

Der Trend zur Fertigung individualisierter Produkte in kleinen Losgrößen erfordert hochflexible Produktionssysteme. Durch die damit verbundene Systemdynamik wird die Reihenfolgeplanung zu einem komplexen Planungsproblem. Der Beitrag beschreibt ein simulationsbasiertes Optimierungsverfahren, welches Echtzeitinformationen zur adaptiven Selektion geeigneter Prioritätsregeln verwendet. Das Potenzial des Ansatzes wird anhand eines Anwendungsfalls aus der Halbleiterindustrie demonstriert.   The trend to manufacturing individualized products in small-scale series demands highly flexible production systems. Because of the dynamic nature of such production systems, scheduling becomes a complex planning problem with frequent need for rescheduling. This article describes a data-driven simulation-based optimization approach using real-time information for adaptive job shop scheduling. The potential of the approach is demonstrated by a use case from semiconductor industry.

Comparison of Wind Turbine Performance Prediction and Measurement

1982 ◽  
Vol 104 (2) ◽  
pp. 84-88 ◽  
Author(s):  
J. L. Tangler
Keyword(s):  
Test Data ◽  
Wind Turbines ◽  
Performance Prediction ◽  
State Of The Art ◽  
Correlation Study ◽  
Performance Models ◽  
Rocky Flats ◽  
Turbine Performance ◽  
Horizontal Axis Wind Turbines ◽  
Development Center

The purpose of this work was to evaluate the state-of-the-art of performance prediction for small horizontal-axis wind turbines. This effort was undertaken since few of the existing performance methods used to predict rotor power output have been validated with reliable test data. The program involved evaluating several existing performance models from four contractors by comparing their predictions for two wind turbines with actual test data. Test data were acquired by Rocky Flats Test and Development Center and furnished to the contractors after submission of their prediction reports. The results of the correlation study will help identify areas in which existing rotor performance models are inadequate and, where possible, the reasons for the models shortcomings. In addition, several problems associated with obtaining accurate test data will be discussed.

scholarly journals Performance measurement and analytic modeling of a web application

2021 ◽  
Author(s):  
Yasir Shoaib
Keyword(s):  
Web Application ◽  
Web Applications ◽  
Research Work ◽  
Queueing Network ◽  
Performance Model ◽  
Load Testing ◽  
Performance Models ◽  
Analytic Modeling ◽  
Service Demand ◽  
Time Required

The performance characteristics such as throughput, resource utilization and response time of a system can be determined through measurement, simulation modeling and analytic modeling. In this thesis, measurement and analytic modeling approaches are applied to study the performance of a Apache-PHP-PostgreSQL web application. Layered Queueing Network (LQN) analytic modeling has been used to represent the system's performance model. The measurements found from load testing are compared with model analysis results for model validation. This thesis aims to show that LQN performance models are versatile enough to allow development of highly granular and easily modifiable models of PHP-based web applications and furthermore are capable of performance prediction with sufficiently high accuracy. Lastly, the thesis also describes utilities and methods used for load testing and determination of service demand parameters in our research work which would aid in shortening time required in development and study of performance models of similar systems.

Mission Performance Model

2015 ◽  
pp. 51-78
Keyword(s):  
Attitude Control ◽  
Large Scale ◽  
Training System ◽  
Performance Model ◽  
Performance Models ◽  
Application Performance ◽  
Mission Success ◽  
Operational Application ◽  
Flight Deck ◽  
Effective Design

Mission Performance Models (MPM) are important to the design of modern digital avionic systems because the flight deck information is no longer obvious. In large-scale dynamic systems, necessary responses to the incoming information model should be a direct correspondence. A Mission Performance Model is an abstract representation of the activity clusters necessary to achieve mission success. The three core activity clusters are trajectory management, energy management, and attitude control and will be covered in detail. Their combined performance characteristics highlight the vehicle's kinematic attributes, which then anticipates unstable conditions. Six MPM are necessary for the effective design and employment of a modern mission-ready flight deck. We describe MPM and their structure, purpose, and operational application. Performance models have many important uses including training system definition and design, avionic system design, and safety programs.

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