OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Hui Cheng Name of the dissertation Causal digraph reasoning for fault diagnosis in paper making applications Manuscript submitted 02.02.2009 Manuscript revised Date of the defence 05.06.2009 Monograph Article dissertation (summary + original articles) Faculty Faculty of Chemistry and M...

In this paper, we present a novel fault detection and fault diagnosis technique for Field Programmable Gate Arrays (FPGAs). The cell is configured to implement a bijective function to simplify the testing of the whole cell array. The whole chip is partitioned into disjoint one-dimensional arrays of cells. For the lookup table (LUT), a fault may occur at the memory matrix, decoder, input or outp...

h.pylori infection stimulates immune responses. these responses at the mucosal level are predominantly of iga types, while circulating antibodies against this microorganism are predominantly igg classes. igm antibodies are rarely found and seem to be non-specific for this bacterium. in this research, water extract antigen, from three strains of h.pylori (isolated from patients with gastritis, d...

For the improvement of reliability, safety and efficiency advanced methods of supervision, fault-detection and fault diagnosis become increasingly important for many technical processes. This holds especially for safety related processes like aircraft, trains, automobiles, power plants and chemical plants. The classical approaches are limit or trend checking of some measurable output variables....

Identification of operating mode is a key step in the fault diagnosis of the hybrid systems. The novelty of this paper is the definition of a hybrid observer where discrete event is identified and then continuous model of a sub-system is selected for the design of observer using sliding mode technique. The observer output is finally used for mode identification and fault diagnosis. The proposed...

Fault detection and diagnosis is an important problem in process engineering. It is the central component of abnormal event management (AEM) which has attracted a lot of attention recently. AEM deals with the timely detection, diagnosis and correction of abnormal conditions of faults in a process. Early detection and diagnosis of process faults while the plant is still operating in a controllab...

This survey of model-based fault diagnosis focuses on those methods that are applicable to aerospace systems. To highlight the characteristics of aerospace models, generic nonlinear dynamical modelling from flight mechanics is recalled and a unifying representation of sensor and actuator faults is presented. An extensive bibliographical review supports a description of the key points of fault d...

In this final part, we discuss fault diagnosis methods that are based on historic process knowledge. We also compare and evaluate the various methodologies reviewed in this series in terms of the set of desirable characteristics we proposed in Part I. This comparative study reveals the relative strengths and weaknesses of the different approaches. One realizes that no single method has all the ...

Fuel cell is one of the best alternatives of fossil energy. However, there are still two barriers: the durability and reliability, which block the wide application of fuel cells. To overcome these barriers, fault diagnosis is an efficient solution. This paper proposes a method for detection of common faults occurring in membrane electrode assemblies (MEA) of fuel cells using image processing to...