Setna rocznica urodzin profesora Mścisława Olechnowicza

Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk

Dependability Evaluation Based on System Monitoring

Non

Tracing Fault Effects in FPGA Systems

The paper presents the extent of fault effects in FPGA based systems and concentrates on transient faults (induced by single event upsets – SEUs) within the configuration memory of FPGA. An original method of detailed analysis of fault effect propagation is presented. It is targeted at microprocessor based FPGA systems using the developed fault injection technique. The fault injection is performed at HDL description level of the microprocessor using special simulators and developed supplementary programs. The proposed methodology is illustrated for soft PicoBlaze microprocessor running 3 programs. The presented results reveal some problems with fault handling at the software level.

Analysing system susceptibility to faults with simulation tools

In the paper we present original fault simulation tools developed in our Institute. These tools are targeted at system dependability evaluation. They provide mechanisms for detailed and aggregated fault effect analysis. Based on our experience with testing various software applications we outline the most important problems and discuss a sample of simulation results

Correlating Time Series Signals and Event Logs in Embedded Systems

In many embedded systems, we face the problem of correlating signals characterising device operation (e.g., performance parameters, anomalies) with events describing internal device activities. This leads to the investigation of two types of data: time series, representing signal periodic samples in a background of noise, and sporadic event logs. The correlation process must take into account clock inconsistencies between the data acquisition and monitored devices, which provide time series signals and event logs, respectively. The idea of the presented solution is to classify event logs based on the introduced similarity metric and deriving their distribution in time. The identified event log sequences are matched with time intervals corresponding to specified sample patterns (objects) in the registered signal time series. The matching (correlation) process involves iterative time offset adjustment. The paper presents original algorithms to investigate correlation problems using the object-oriented data models corresponding to two monitoring sources. The effectiveness of this approach has been verified in power consumption analysis using real data collected from the developed Holter device. It is quite universal and can be easily adapted to other device optimisation problems

Enhancing Software Project Monitoring with Multidimensional Data Repository Mining

Software project development and maintenance activities have been reported in various repositories. The data contained in these repositories have been widely used in various studies on specific problems, e.g., predicting bug appearance, allocating issues to developers, and identifying duplicated issues. Developed analysis schemes are usually based on simplified data models while issue report details are neglected. Confronting this problem requires a deep and wide-ranging exploration of software repository contents adapted to their specificities, which differs significantly from classical data mining. This paper is targeted at three aspects: the structural and semantic exploration of repositories, deriving characteristic features in value and time perspectives, and defining the space of project monitoring goals. The considerations presented demonstrate a holistic image of the project development process, which is useful in the assessment of its efficiency and identification of imperfections. The original analysis introduced in this work was verified using open source and some commercial software project repositories