Introduction to Performance Monitoring and Tuning

2006 ◽  
pp. 234-269
Author(s):  
B. M. Subraya
Keyword(s):  
Operating System ◽  
Architectural Design ◽  
Performance Monitoring ◽  
Web Applications ◽  
Operating Conditions ◽  
Performance Data ◽  
Operational Environment ◽  
Operational Conditions ◽  
Technology Level ◽  
Level Monitoring

For any applications to be performance conscious, its performance must be monitored continuously. Monitoring performance is a necessary part of the preventive maintenance of the application. By monitoring, we obtain performance data which are useful in diagnosing performance problems under operational conditions. Based on data collected through monitoring, one can define a baseline — a range of measurements that represent acceptable performance under typical operating conditions. This baseline provides a reference point that makes it easier to spot problems when they occur. In addition, during troubleshooting system problems, performance data give information about the behavior of system resources at the time the problem occurs, which is useful in pinpointing the cause. In order to monitor the system, the operational environment provides various parameters implemented through counters for collection of performance data. Applications developed must ultimately be installed and run on a specific operating system. Hence, applications performance also depends on factors that govern the operating system. Each operating system has its own set of performance parameters to monitor and tune for better performance. Performance of applications also depends on the architectural level monitoring and tuning. However, architectural design depends on specific technology. Hence, technology level monitoring and tuning must be addressed for better results. To achieve all these, proper guidelines must be enforced at various stages for monitoring and tuning. All the previous chapters, together, described the performance testing from concept to reality whereas this chapter highlights aspects of monitoring and tuning to specific technologies. This chapter provides an overview of monitoring and tuning applications with frameworks in Java and Microsoft .NET technologies. Before addressing the technology specific performance issues, we need to know the overall bottlenecks that arise in Web applications.

Comparison of Wind Tunnel Airfoil Performance Data With Wind Turbine Blade Data

1992 ◽  
Vol 114 (2) ◽  
pp. 119-124 ◽  
Author(s):  
C. P. Butterfield ◽  
George Scott ◽  
Walt Musial
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Peak Power ◽  
Unsteady Aerodynamics ◽  
Leading Edge ◽  
Operating Conditions ◽  
Performance Data ◽  
Horizontal Axis Wind Turbine ◽  
Force Coefficients ◽  
Basic Fluid

Horizontal axis wind turbine (HAWT) performance is usually predicted by using wind tunnel airfoil performance data in a blade element momentum theory analysis. This analysis assumes that the rotating blade airfoils will perform as they do in the wind tunnel. However, when stall-regulated HAWT performance is measured in full-scale operation, it is common to find that peak power levels are significantly greater than those predicted. Pitch-controlled rotors experience predictable peak power levels because they do not rely on stall to regulate peak power. This has led to empirical corrections to the stall predictions. Viterna and Corrigan (1981) proposed the most popular version of this correction. But very little insight has been gained into the basic cause of this discrepancy. The National Renewable Energy Laboratory (NREL), funded by the DOE, has conducted the first phase of an experiment which is focused on understanding the basic fluid mechanics of HAWT aerodynamics. Results to date have shown that unsteady aerodynamics exist during all operating conditions and dynamic stall can exist for high yaw angle operation. Stall hysteresis occurs for even small yaw angles and delayed stall is a very persistent reality in all operating conditions. Delayed stall is indicated by a leading edge suction peak which remains attached through angles of attack (AOA) up to 30 degrees. Wind tunnel results show this peak separating from the leading edge at 18 deg AOA. The effect of this anomaly is to raise normal force coefficients and tangent force coefficients for high AOA. Increased tangent forces will directly affect HAWT performance in high wind speed operation. This report describes pressure distribution data resulting from both wind tunnel and HAWT tests. A method of bins is used to average the HAWT data which is compared to the wind tunnel data. The analysis technique and the test set-up for each test are described.

scholarly journals Performance analysis of the working surface of the rails from test batches on the Test Loop of JSC “VNIIZhT”

2018 ◽  
Vol 77 (3) ◽  
pp. 141-148
Author(s):  
M. Yu. Khvostik ◽  
I. V. Khromov ◽  
O. A. Bykova ◽  
G. A. Beresten’
Keyword(s):  
Wear Resistance ◽  
Operating Time ◽  
Operating Conditions ◽  
Continuous Change ◽  
Wear Area ◽  
Railway Network ◽  
Operational Conditions ◽  
Rolling Surface ◽  
Test Loop ◽  
The Impact

The monitoring of railway rails damage on the railway network of the JSC “Russian Railways” as well as operational and polygon tests are conducted with the purpose of assessing the impact of operating conditions on the intensity of rails damage, obtaining initial data for forecasting rails failures. The increased intensity of rails wear on sites with a complex plan and profile leads to the fact that with a continuous change from the track, rails which have an underutilized service life of more than 20 % are retrieved. Polygon tests on the Test Loop of the JSC “VNIIZhT” near the Scherbinka station can provide the repeatability and reliability of the results, comparative tests are carried out under identical conditions and their duration is several times less than when tested at experimental sites under operational conditions. The results of the polygon tests of new differentially heat-strengthened rails did not reveal any advantages in the wear resistance of special purposed rails (laid in the recommended radius of the curve for its application) when comparing the rails of domestic manufacturers. Metal shelling out on the rolling surface of rails is the main reason for the removal of rails from test batches. The origin and development of defects of this kind is due to both violations of the technology of manufacturing rails, and because of violations of the current maintenance of the track. The metal stock in the area of the rail head of R65 type due to the increase in its dimensions positively affects the extension of the lifetime of the rails, reducing the cost of the life cycle and the rail itself, and the design of the track as a whole. When carrying out a separate study in order to obtain results characterizing the stability of high-quality rails to contact fatigue damage, it is advisable to optimize the conditions of the polygon tests, bringing them closer to operational ones. When forming the test results, it is necessary to expand the list of criteria for assessing the wear resistance of rails, supplementing it with the size of the wear area at the time of a certain operating time of the tonnage, with the introduction of this criterion into the appropriate methods for the polygon (operational) tests.

Maximising Asset Value through Implementation of Dynamic Well Operating Envelop

2021 ◽  
Author(s):  
Rafael Islamov ◽  
Eghbal Motaei ◽  
Bahrom Madon ◽  
Khairul Azhar Abu Bakar ◽  
Victor Hamdan ◽  
...  
Keyword(s):  
Real Time ◽  
Performance Monitoring ◽  
Oil And Gas ◽  
Operating Conditions ◽  
Well Performance ◽  
Time Dynamic ◽  
Well Model ◽  
Maximum Range ◽  
Facilities Design ◽  
Well Models

Abstract Dynamic Well Operating Envelop (WOE) allows to ensure that well is maintained and operated within design limits and operated in the safe, stable and profitable way. WOE covers the Well Integrity, Reservoir constraints and Facility limitations and visualizes them on well performance chart (Hamzat et al., 2013). Design and operating limits (such as upper and lower completion/facilities design pressures, sand failure, erosion limitations, reservoir management related limitations etc) are identified and translated into two-dimensional WOE (pressure vs. flowrate) to ensure maximum range of operating conditions that represents safe and reliable operation are covered. VLP/IPR performance curves were incorporated based on latest Validated Well Model. Optimum well operating window represents the maximum range of operating conditions within the Reservoir constraints assessed. By introducing actual Well Performance data the optimisation opportunities such as production/injection enhancement identified. During generating the Well Operating Envelops tremendous work being done to rectify challenges such as: most static data (i.e. design and reservoir limitations) are not digitized, unreliable real-time/dynamic data flow (i.e. FTHP, Oil/Gas rates etc), disintegrated and unreliable well Models and no solid workflows for Flow assurance. As a pre-requisite the workflows being developed to make data tidy i.e.ready and right, and Well Model inputs being integrated to build updated Well Models. Successful WOE prototype is generated for natural and artificially lifted Oil and Gas wells. Optimisation opportunities being identified (i.e. flowline pressure reduction, reservoir stimulation and bean-up) Proactive maintenance is made possible through dynamic WOE as a real time exceptional based surveillance (EBS) tool which is allowing Asset engineers to conduct the well performance monitoring, and maintain it within safe, stable and profitable window. Additionally, it allows to track all Production Enhancement jobs and seamless forecasting for new opportunities.

Wavelet Transform Modulus Maxima Decay Lines

2015 ◽  
pp. 48-68
Author(s):  
Andreas Kyprianou ◽  
Andreas Tjirkallis
Keyword(s):  
Experimental Data ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Environmental Conditions ◽  
Simulated Data ◽  
Random Excitation ◽  
Operating Conditions ◽  
Structural Behaviour ◽  
Operational Conditions ◽  
Three Degree Of Freedom

An important task in structural health monitoring (SHM) is that of damage detection under varying environmental and operational conditions. Structures, under varying environmental conditions, change their mass, elasticity and damping properties whereas changing operational conditions cause changes to excitations. A damage detection methodology implemented in these circumstances faces serious challenges since changes to structural behaviour imparted by environmental or operational conditions could be wrongly attributed to damage. The part of a damage detection decision algorithm that removes environmental and operational effects is called normalization. In this chapter a normalization methodology that is based on the similarity between continuous wavelet transform maxima decay lines is presented. This methodology is implemented on both simulated and experimental data. Simulated data were obtained from a three degree of freedom system. Varying environmental conditions were simulated by temperature dependent stiffness parameters and operating conditions by changing the colour of random excitation. Experimental data were obtained from damaged cantilever beams that were subjected to random excitations of different colour and varying temperatures.

scholarly journals Continuous electrochemical reactor improved by the addition of Moringa oleífera lam extract: optimization of operational conditions for Blue 5G dye removal

2019 ◽  
Vol 14 (3) ◽  
pp. 1
Author(s):  
Bruna Souza dos Santos ◽  
Eduardo Eyng ◽  
Paulo Rodrigo Stival Bittencourt ◽  
Laercio Mantovani Frare ◽  
Éder Lisandro de Moraes Flores ◽  
...  
Keyword(s):  
Retention Time ◽  
Moringa Oleifera ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Current Intensity ◽  
Quadratic Model ◽  
Residual Concentration ◽  
Natural Coagulant ◽  
Operational Conditions ◽  
Moringa Oleifera Lam

Wastewaters from textile industries are known for their difficulty to treat, several alternative technologies are applied for their treatment. In this context, the study examined a hybrid treatment system, composed of electrocoagulation combined with a natural coagulant (extract of Moringa oleífera lam seeds) to remove reactive dye Blue 5G aqueous solutions. The work evaluated the use of milder operating conditions to improve the efficiency of treatment, with reduced demands for electrical power and coagulant.  The following factors were evaluated: electric current intensity, natural coagulant concentration and hydraulic retention time. A quadratic model was adjusted and validated at a 5% significance level. The overall optimization resulted in conditions of 0.28 A for electrical current intensity, 1000.00 mg L-1 of aqueous extract of Moringa oleífera lam and 5 min for hydraulic retention time. While operating under optimal conditions, the removal of 71.38% of color and 5.22 mg L-1 of iron residual concentration was achieved.

scholarly journals Critical Infrastructures: The Operational Environment in Cases of Severe Disruption

2019 ◽  
Vol 11 (3) ◽  
pp. 838 ◽  
Author(s):  
Ossi Heino ◽  
Annina Takala ◽  
Pirjo Jukarainen ◽  
Joanna Kalalahti ◽  
Tuula Kekki ◽  
...  
Keyword(s):  
Emergency Services ◽  
Critical Infrastructure ◽  
Service Providers ◽  
Terrorist Attack ◽  
Critical Infrastructures ◽  
Operational Environment ◽  
Electricity Grid ◽  
Operational Conditions ◽  
Key Stakeholders ◽  
Administrative Structures

The functioning and resilience of modern societies have become more and more dependent on critical infrastructures. Severe disturbance to critical infrastructure is likely to reveal chaotic operational conditions, in which infrastructure service providers, emergency services, police, municipalities, and other key stakeholders must act effectively to minimize damages and restore normal operations. This paper aims to better understand this kind of operational environment resulting from, for example, a terrorist attack. It emphasizes mutual interdependencies among key stakeholders in such situations. The empirical contribution is based on observations from a workshop, in which participants representing the critical services and infrastructures in Finland discussed in thematic groups. Two scenarios guided the workshop discussions; nationwide electricity grid disruption and presumably intentionally contaminated water supply in a city. The results indicate that more attention should be paid to the interdependencies between critical infrastructures, as well as to the latent vulnerabilities hidden inside the systems. Furthermore, producing security seems to require continuous interaction and creation of meanings between extremely different actors and logics. This implies a need for changes in thinking, particularly concerning the ability to define problems across conventional administrative structures, geographical boundaries and conferred powers.

scholarly journals Evaluation of Solar Radiation Transposition Models for Passive Energy Management and Building Integrated Photovoltaics

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 702 ◽  
Author(s):  
Carlos Toledo ◽  
Ana Maria Gracia Amillo ◽  
Giorgio Bardizza ◽  
Jose Abad ◽  
Antonio Urbina
Keyword(s):  
Solar Radiation ◽  
Horizontal Plane ◽  
Architectural Design ◽  
Operating Conditions ◽  
Geographical Information ◽  
Medium Temperature ◽  
Building Integrated Photovoltaics ◽  
Wide Range ◽  
Radiation Modelling ◽  
Winter Time

Incident solar radiation modelling has become of vital importance not only in architectural design considerations, but also in the estimation of the energy production of photovoltaic systems. This is particularly true in the case of buildings with integrated photovoltaics (PV) systems having a wide range of orientations and inclinations defined by the skin of the building. Since solar radiation data at the plane of interest is hardly ever available, this study presents the analysis of two of the most representative transposition models used to obtain the in-plane irradiance using as input data the global and diffuse irradiation on the horizontal plane, which can be obtained by satellite-based models or ground measurements. Both transposition models are validated with experimental measurements taken in Murcia (southeast of Spain) and datasets provided by the photovoltaic geographical information system (PVGIS) and the National Renewable Energy Laboratory (NREL) for vertical surfaces facing the four cardinal points. For the validation, the mean bias deviation, root mean square error and forecasted skill were used as indicators. Results show that the error rate decreases slightly for clear days. Better results are also obtained by dismissing data with low solar elevation angles so as to avoid shadowing effects from the surroundings in the early and late hours of the day, which affects mainly the performance of the transposition models for west and east surfaces. The results highlight the potential of equator-facing façades in winter time when the received irradiation can be twice as much as the one collected by the horizontal plane. It is also noteworthy that the operating conditions of all façades are mainly low irradiance and medium temperature at these locations.

Floating Frame of Reference formulation for modeling flexible multi-body systems in premise operational conditions

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2706-2720
Author(s):  
Ayman Nada ◽  
Abdullatif Bishiri
Keyword(s):  
Frame Of Reference ◽  
Suitable Model ◽  
Operational Environment ◽  
Operational Conditions ◽  
Floating Frame Of Reference ◽  
Scientific Papers ◽  
Floating Frame ◽  
Coordinate Reduction ◽  
Frequency Domain Decomposition ◽  
Multi Body

The Floating Frame of Reference (FFR) formulation is a well-established and reliable method for modeling flexible multi-body systems. The FFR formulation has been adopted for dynamic systems that are characterized by large rotations with relatively small deformations. Many scientific papers have pointed out these characteristics with the scrutiny of the simulation results and comparisons with other modeling techniques. However, the FFR is still enclosed in the theoretical aspects and simulation work and faces difficulties when being applied to practical systems. The crucial point in these difficulties centers on coordinate reduction and the associated mapping between nodal and modal coordinates. The process of selecting the necessary modes may be theoretically simple, but the situation is different when applied in a real operational environment. The strategy developed in this work combines the Operational Modal Analysis, specifically the Frequency Domain Decomposition (FDD) approach, and the FFR formulation to build a suitable model of practical multi-body systems. The output model has been validated experimentally. The results show that the proposed FFR-FDD method can be efficiently used to construct multi-body models for those systems that work in premise operational conditions.

A Human Reliability Analysis to Crankshaft Overhauling in Dry-Docking of a General Cargo Ship

2020 ◽  
pp. 147509022094833
Author(s):  
Samet Bicen ◽  
Cagatay Kandemir ◽  
Metin Celik
Keyword(s):  
Reliability Analysis ◽  
Human Error ◽  
Task Type ◽  
Operating Conditions ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Operational Conditions ◽  
Safety Issues ◽  
Immediate Recovery ◽  
General Cargo

This study conducts a practical application of shipboard operation human reliability analysis (SOHRA) to a crankshaft overhauling operation of a general cargo ship at dry-docking period. The SOHRA approach includes error producing condition (EPC) and general task type (GTT) parameters to consistently calculate the human error probability (HEP) values of operation steps. In this case, a comprehensive overhauling of main engine was planned at shipyard since the ship has experienced a catastrophic failure. An onboard survey to ship engine room is conducted to monitor the operational conditions. The targeted operation, involves disassembly, maintenance, and reassembly stages, is monitored based on 39 sub-tasks. According to the initial findings, immediate recovery actions are suggested to eliminate critical safety issues in a timely manner. Moreover, an extended discussion through long-term safety recommendations are also provided. The results revealed from case study illustrates that HEP values in maintenance operations are sensitive to ship operating conditions. The proposed approach is found very useful by company executives to support ship technical superintendents in critical operation monitoring. The further study is considered to develop mobile application of SOHRA specific to maintenance operations onboard ships.

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