Comparison of different classification algorithms for fault detection and fault isolation in complex systems

Due to the lack of sufficient results seen in literature, feature extraction and classification methods of hydraulic systems appears to be somewhat challenging. This paper compares the performance of three classifiers (namely linear support vector machine (SVM), distance-weighted k-nearest neighbor (WKNN), and decision tree (DT) using data from optimized and non-optimized sensor set solutions. The algorithms are trained with known data and then tested with unknown data for different scenarios characterizing faults with different degrees of severity. This investigation is based solely on a data-driven approach and relies on data sets that are taken from experiments on the fuel system. The system that is used throughout this study is a typical fuel delivery system consisting of standard components such as a filter, pump, valve, nozzle, pipes, and two tanks. Running representative tests on a fuel system are problematic because of the time, cost, and reproduction constraints involved in capturing any significant degradation. Simulating significant degradation requires running over a considerable period; this cannot be reproduced quickly and is costly

Fault-tolerant computer study

A set of building block circuits is described which can be used with commercially available microprocessors and memories to implement fault tolerant distributed computer systems. Each building block circuit is intended for VLSI implementation as a single chip. Several building blocks and associated processor and memory chips form a self checking computer module with self contained input output and interfaces to redundant communications buses. Fault tolerance is achieved by connecting self checking computer modules into a redundant network in which backup buses and computer modules are provided to circumvent failures. The requirements and design methodology which led to the definition of the building block circuits are discussed

Design of CMOS PSCD circuits and checkers for stuck-at and stuck-on faults

[[abstract]]We present in this paper an approach to designing partially strongly code-disjoint (PSCD) CMOS circuits and checkers, considering transistor stuck-on faults in addition to gate-level stuck-at faults. Our design-for-testability (DFT) technique requires only a small number of extra transistors for monitoring abnormal static currents, coupled with a simple clocking scheme, to detect the stuck-on faults concurrently. The DFT circuitry not only can detect the faults in the functional circuit but also can detect or tolerate faults in itself, making it a good candidate for checker design. Switch and circuit level simulations were performed on a sample circuit, and a sample 4-out-of-8 code checker chip using the proposed technique has been designed, fabricated, and tested, showing the correctness of the method. Performance penalty is reduced by a novel BiCMOS checker circuit.[[fileno]]2030108010057[[department]]電機工程學

Multidisciplinary Approaches and Challenges in Integrating Emerging Medical Devices Security Research and Education

Traditional embedded systems such as secure smart cards and nano-sensor networks have been utilized in various usage models. Nevertheless, emerging secure deeply-embedded systems, e.g., implantable and wearable medical devices, have comparably larger “attack surface”. Specifically, with respect to medical devices, a security breach can be life-threatening (for which adopting traditional solutions might not be practical due to tight constraints of these often-battery-powered systems), and unlike traditional embedded systems, it is not only a matter of financial loss. Unfortunately, although emerging cryptographic engineering research mechanisms for such deeply-embedded systems have started solving this critical, vital problem, university education (at both graduate and undergraduate level) lags comparably. One of the pivotal reasons for such a lag is the multi-disciplinary nature of the emerging security bottlenecks. Based on the aforementioned motivation, in this work, at Rochester Institute of Technology, we present an effective research and education integration strategy to overcome this issue in one of the most critical deeply-embedded systems, i.e., medical devices. Moreover, we present the results of two years of implementation of the presented strategy at graduate-level through fault analysis attacks, a variant of side-channel attacks. We note that the authors also supervise an undergraduate student and the outcome of the presented work has been assessed for that student as well; however, the emphasis is on graduate-level integration. The results of the presented work show the success of the presented methodology while pinpointing the challenges encountered compared to traditional embedded system security research/teaching integration of medical devices security. We would like to emphasize that our integration approaches are general and scalable to other critical infrastructures as well