Abstract: This document describes a framework for measuring and improving the performance of applications, such as distributed applications and web applications. In one aspect, a method includes performing a test on an application. The test includes executing the application on one or more computers and, while executing the application, simulating a set of workload scenarios for which performance of the application is measured during the test. While performing the test, a set of performance metrics that indicate performance of individual components involved in executing the application during the test is obtained. A knowledge graph is queried using the set of performance metrics. The knowledge graph links the individual components to corresponding performance metrics and defines a set of hotspot conditions that are each based on one or more of the corresponding performance metrics for the individual components. A given hotspot condition is detected based on the set of performance metrics.

Abstract: This document describes a framework for measuring and improving the performance of applications, such as distributed applications and web applications. In one aspect, a method includes performing a test on an application. The test includes executing the application on one or more computers and, while executing the application, simulating a set of workload scenarios for which performance of the application is measured during the test. While performing the test, a set of performance metrics that indicate performance of individual components involved in executing the application during the test is obtained. A knowledge graph is queried using the set of performance metrics. The knowledge graph links the individual components to corresponding performance metrics and defines a set of hotspot conditions that are each based on one or more of the corresponding performance metrics for the individual components. A given hotspot condition is detected based on the set of performance metrics.

Abstract: A system and method for controlling gas turbine engines with maximum thrust of less than 500 kgf. The control system includes electronic control unit (“ECU”), sensors and actuators. To ensure the requirement of compactness, physical control system simplicity but maintain stability and accurate operation for the engine, the control system does not include components such as Fuel Control Unit (“FCU”), alternator and corresponding rectifier circuits. A sensor, instead of alternator's wave form signal, is used to detect the rotational speed of the engine. Voltage regulation into the electric motor driving the fuel pump controls fuel flow, instead of the FCU. The control method consists of upper and lower limits computation calculation blocks of the control signal, and PID control algorithm block with coefficients designed to be suitable for the engine operating ranges. Control is implemented through a 7-step calculation process. Piecewise linearization modeling and tuning PID coefficients is also presented.