This paper describes an integrated approach to diagnosis of complex dynamic systems, combining model based diagnosis with machine learning techniques, proposing a simple framework to make them cooperate, hence improving the diagnosis capabilities of each individual method. First step in the diagnosis process resorts to consistency-based diagnosis, via possible conflicts, which allows fault dete...

Among the many kinds of networking technologies, the wireless ad hoc network is an important one for creating high-performance ubiquitous computing systems. The availability of a wireless ad hoc network (WANET) depends highly upon the level of node reliability. System-level fault diagnosis has long been a subject for the purpose of maintaining system reliability. This paper addresses the compar...

An unknown input high gain observer (UIHGO) based component fault detection and isolation (FDI) technique is presented. First, a reduced order UIHGO is derived for a linear system whose parameters are uncertain to some extent. The observer gain is determined by solving the well-known algebraic Riccati equation (ARE). Then, using a bank of such observers, a FDI algorithm is devised to detect and...

We examine the formation of giant elliptical galaxies using their globular cluster (GC) systems as probes of their evolutionary history. The bimodal distributions of GC metallicities in such galaxies are often cited as evidence for the formation of giant elliptical galaxies through mergers involving gas-rich spirals, with the metal-rich GCs forming during the merger process. We explore an alter...

We study the stability of the giant gravitons in the string theory background with NSNS B field. We consider the perturbation of giant gravitons formed by a probe D(8− p) brane in the background generated by D(p− 2)D(p) branes for 2 ≤ p ≤ 5. We use the quadratic approximation to the brane action to find the equations of motion. The vibration modes for ρ , φ and r are coupled, while those of xk’...

Multi-Resolution Fault Diagnosis in Discrete-Event Systems . JiangJing Pan Concordia University In this thesis, a framework for multi-resolution fault diagnosis in discrete-event systems (DES) is introduced. Here a sequence of plant models, with increasing resolution, are used in fault diagnosis and the range of possible diagnosis is narrowed down step by step, until the failure mode is isolate...

Quantum error correction allows one to make quantum computers fault-tolerant against unavoidable errors due to decoherence and imperfect physical gate operations. However, the fault-tolerant quantum computation requires impractically large computational resources for useful applications. This is a current major obstacle to the realization of a quantum computer. In particular, magic state distil...

Paying off the mortgage, once a widespread rite of passage for homeowners approaching retirement, has become less common in recent years. Concerns are mounting that the increased prevalence of housing debt among older homeowners could compromise financial security in retirement by expanding housing affordability problems, crimping essential nonhousing spending, increasing vulnerability to home ...