Investigations into the feasibility of an on-line test methodology

This thesis aims to understand how information coding and the protocol that it supports can affect the characteristics of electronic circuits. More specifically, it investigates an on-line test methodology called IFIS (If it Fails It Stops) and its impact on the design, implementation and subsequent characteristics of circuits intended for application specific lC (ASIC) technology. The first study investigates the influences of information coding and protocol on the characteristics of IFIS systems. The second study investigates methods of circuit design applicable to IFIS cells and identifies the· technique possessing the characteristics most suitable for on-line testing. The third study investigates the characteristics of a 'real-life' commercial UART re-engineered using the techniques resulting from the previous two studies. The final study investigates the effects of the halting properties endowed by the protocol on failure diagnosis within IFIS systems. The outcome of this work is an identification and characterisation of the factors that influence behaviour, implementation costs and the ability to test and diagnose IFIS designs

Robust design of deep-submicron digital circuits

Avec l'augmentation de la probabilité de fautes dans les circuits numériques, les systèmes développés pour les environnements critiques comme les centrales nucléaires, les avions et les applications spatiales doivent être certifies selon des normes industrielles. Cette thèse est un résultat d'une cooperation CIFRE entre l'entreprise Électricité de France (EDF) R&D et Télécom Paristech. EDF est l'un des plus gros producteurs d'énergie au monde et possède de nombreuses centrales nucléaires. Les systèmes de contrôle-commande utilisé dans les centrales sont basés sur des dispositifs électroniques, qui doivent être certifiés selon des normes industrielles comme la CEI 62566, la CEI 60987 et la CEI 61513 à cause de la criticité de l'environnement nucléaire. En particulier, l'utilisation des dispositifs programmables comme les FPGAs peut être considérée comme un défi du fait que la fonctionnalité du dispositif est définie par le concepteur seulement après sa conception physique. Le travail présenté dans ce mémoire porte sur la conception de nouvelles méthodes d'analyse de la fiabilité aussi bien que des méthodes d'amélioration de la fiabilité d'un circuit numérique.The design of circuits to operate at critical environments, such as those used in control-command systems at nuclear power plants, is becoming a great challenge with the technology scaling. These circuits have to pass through a number of tests and analysis procedures in order to be qualified to operate. In case of nuclear power plants, safety is considered as a very high priority constraint, and circuits designed to operate under such critical environment must be in accordance with several technical standards such as the IEC 62566, the IEC 60987, and the IEC 61513. In such standards, reliability is treated as a main consideration, and methods to analyze and improve the circuit reliability are highly required. The present dissertation introduces some methods to analyze and to improve the reliability of circuits in order to facilitate their qualification according to the aforementioned technical standards. Concerning reliability analysis, we first present a fault-injection based tool used to assess the reliability of digital circuits. Next, we introduce a method to evaluate the reliability of circuits taking into account the ability of a given application to tolerate errors. Concerning reliability improvement techniques, first two different strategies to selectively harden a circuit are proposed. Finally, a method to automatically partition a TMR design based on a given reliability requirement is introduced.PARIS-Télécom ParisTech (751132302) / SudocSudocFranceF

On Fault Tolerance Methods for Networks-on-Chip

Technology scaling has proceeded into dimensions in which the reliability of manufactured devices is becoming endangered. The reliability decrease is a consequence of physical limitations, relative increase of variations, and decreasing noise margins, among others. A promising solution for bringing the reliability of circuits back to a desired level is the use of design methods which introduce tolerance against possible faults in an integrated circuit. This thesis studies and presents fault tolerance methods for network-onchip (NoC) which is a design paradigm targeted for very large systems-onchip. In a NoC resources, such as processors and memories, are connected to a communication network; comparable to the Internet. Fault tolerance in such a system can be achieved at many abstraction levels. The thesis studies the origin of faults in modern technologies and explains the classification to transient, intermittent and permanent faults. A survey of fault tolerance methods is presented to demonstrate the diversity of available methods. Networks-on-chip are approached by exploring their main design choices: the selection of a topology, routing protocol, and flow control method. Fault tolerance methods for NoCs are studied at different layers of the OSI reference model. The data link layer provides a reliable communication link over a physical channel. Error control coding is an efficient fault tolerance method especially against transient faults at this abstraction level. Error control coding methods suitable for on-chip communication are studied and their implementations presented. Error control coding loses its effectiveness in the presence of intermittent and permanent faults. Therefore, other solutions against them are presented. The introduction of spare wires and split transmissions are shown to provide good tolerance against intermittent and permanent errors and their combination to error control coding is illustrated. At the network layer positioned above the data link layer, fault tolerance can be achieved with the design of fault tolerant network topologies and routing algorithms. Both of these approaches are presented in the thesis together with realizations in the both categories. The thesis concludes that an optimal fault tolerance solution contains carefully co-designed elements from different abstraction levelsSiirretty Doriast

Concurrent error detection

Concurrent error detection (CED) is the detection of errors or faults in a circuit or data path concurrent with normal operation of that circuit. The general approach for CED is to calculate a check symbol for the inputs to the circuit under operation, predict the check symbol that will result for the output of the circuit for those inputs, and compare the predicted check symbol to the one that is actually calculated for the output. If the predicted and actual check symbols are different, an error or fault has been detected. The alternative to this check symbol prediction is to use a second copy of the circuit under operation and compare the results of the two circuits. For some classes of circuits the prediction of the output check symbol can require less circuitry than a second copy of the circuit being tested. Four examples of these types of circuits are examined in this dissertation: Arithmetic Logic Units (ALUs), array multipliers, self-synchronous scrambler-descrambler pairs with their intervening data path, and switch fabrics. Faults in integrated circuits tend to produce unidirectional errors. Unidirectional errors are those in which all of the errors are in the same direction (e.g., 0 to 1 errors) within the block of data covered by a given check symbol. For this reason, codes that are optimized for unidirectional errors are the focus of investigation for most of the applications. In particular, the Bose-Lin codes are examined for those applications where unidirectional errors are expected to be typical. In order to examine the performance of the Bose-Lin codes in one of these applications, it was necessary to determine the theoretical performance for Bose- Lin codes for error rates beyond what had been previously studied. This analysis of Bose-Lin codes with large numbers of "burst" errors also included a further generalization of the codes

Unidirectional error correcting/detecting codes

An extensive theory of symmetric error control coding has been developed in the last few decades. The recently developed VLSI circuits, ROM, and RAM memories have given an impetus to the extension of error control coding to include asymmetric and unidirectional types of error control. The maximal numbers of unidirectional errors which can be detected by systematic codes using r checkbits are investigated. They are found for codes with k, the number of information bits, being equal to 2[superscript r] and 2[superscript r] + 1. The importance of their characteristic in unidirectional error detection is discussed. A new method of constructing a systematic t-error correcting/all-unidirectional error detecting(t-EC/AUED) code, which uses fewer checkbits than any of the previous methods, is developed. It is constructed by appending t + 1 check symbols to a systematic t-error correcting and (t+l)-error detecting code. Its decoding algorithm is developed. A bound on the number of checkbits for a systematic t-EC/AUED code is also discussed. Bose-Rao codes, which are the best known single error correcting/all-unidirectional error detecting(SEC/AUED) codes, are completely analyzed. The maximal Bose-Rao codes for a fixed weight and for all weights are found. Of course, the base group and the group element which make the Bose-Rao code maximal are found, too. The bounds on the size of SEC/AUED codes are discussed. Nonsystematic single error correcting/d-unidirectional error detecting codes are constructed. Three methods for constructing the systematic t-error correcting/d-unidirectional error detecting(t-EC/d-UED) codes are developed. From these, simple and efficient t-EC/(t+2)-UED codes are derived. The decoding algorithm for one of these methods, which can be applied to the other two methods with slight modification, is described. A lower bound on the number of checkbits for a systematic t-EC/d-UED code is derived. Finally, future research efforts are proposed

Listening to the Experts: Correctional and Community College Administrators’ Perceptions of How Collaboration Contributes to the Public Value of a Postsecondary Correctional Education Partnership

This research examined correctional and community college administrators\u27 perceptions of collaboration and the public value impact of a PSCE partnership through a systems thinking conceptual framework. Through interviews, observations, and document reviews, I determined how these perceptions aligned with the public value of a PSCE partnership. This was a basic qualitative study involving six participants from two public agencies. Findings from this study indicate that administrators recognized: Public Safety Realignment legislation contributed to the viability of a PSCE partnership in a county jail system. Public safety improvements in the county jail system promoted a jail environment to facilitate the success of a PSCE partnership. Service coordination with jail in-reach services promoted a continuum of services to enhance the PSCE partnership. An improved jail culture has contributed to the collaboration by administrators of the PSCE partnership. Improved interagency communication has contributed to a better understanding of the missions of both partners. Promoting correctional best practices has contributed to improving the collection of program data of the PSCE partnership. Recommendations for practice and for future research are provided

A QUALITATIVE STUDY OF STROKE SURVIVORS’ EXPERIENCE OF SENSORY CHANGES

Background. Previous literature examined tactile and proprioceptive changes after stroke; however, the lived experience of changes in all sensory systems is still a gap in the literature. Purpose. To gain understanding of stroke survivors’ experience of sensory changes and how sensory changes impact participation in daily life activities. Method. This study utilized a qualitative description method. Researchers used semi-structured interviews with probing questions. Inductive content analysis approach was used to analyze the data. Researchers recruited thirteen stroke survivors ≤ 75 years old who participated in a community program. Findings. Emerging themes included Daily Life Impact of Sensory Function Changes, and Experience and Timing of Sensory Changes. Participants experienced changes in various sensory systems including touch and proprioception, visual, auditory, and taste. Survivors also reported sensitivity to environmental stimuli. Sensory changes affect survivors’ participation in daily life. Implications. Results from this study inform health care providers about stroke survivors’ sensory needs to help them design interventions that match their needs

Attention and Working Memory Deficits in OCD Checking Behaviour

The evidence for memory impairments in obsessive-compulsive disorder (OCD) is mixed (Hermans et al., 2008). For example, findings are inconsistent, whether OCD have poorer memory capacity compared to neuro-typical controls, or whether verbal memory is less affected than visuospatial memory (Muller and Roberts, 2005b). Some evidence (Greisberg and McKay, 2003) pointed to a more subtle interaction with executive dysfunction leading to impaired memory performance. In a review of 58 experiments Harkin and Kessler (2011) argued that rather than classifying memory deficits in OCD by modality, for example verbal vs visuospatial, it is more instructive to classify the experiments by their task demand in terms of Executive function (E), Binding complexity (B) and memory Load (L). Using the EBL classification system in combination with the Baddeley model of working memory (Baddeley 2000) with an episodic buffer, performance in working memory tasks could be better explained in terms of task demands of executive function. For example, working memory (WM) performance of subclinical OCD checkers can be impaired if presented with irrelevant but misleading information during the retention period. The aim of this thesis was firstly, using magnetoencephalography (MEG) and a paradigm designed to provoke executive dysfunction in OCD participants, to measure the neural correlates of deficient working memory processing. Secondly, to use MEG to investigate the neural correlates of attentional bias and executive dysfunction in OCD checking behaviour when engaged in an endogenous attention (Stroop) task. Lastly, using transcranial magnetic stimulation (TMS) to target task relevant brain areas in attempt to affect beneficially the task performance of OCD checker participants engaged in an exogenous attention (Inhibition of Return) task, an endogenous attention (Stroop) task and in the working memory task. Using ecologically valid stimuli that resonate with the checkers’ OCD related concerns, the neuroimaging data revealed different patterns of activity, comparing subclinical OCD checkers with neuro-typical controls. These patterns are consistent with the stimuli provoking deficient executive function in the subclinical checkers. The brain activity recorded was consistent with repeated memory checking and poor suppression of irrelevant stimuli. Efforts to remediate executive dysfunction with TMS were only partially successful. In accord with the EBL classification system, the ecologically valid threat stimuli in combination with the WM and Stroop tasks were successful in exploiting executive dysfunction in subclinical checkers in domains of working memory and endogenous attention. Neural correlates of the impaired processing were measured successfully using MEG

AGAINST ALL ODDS: ACCESS AND ACHIEVEMENT OF AFRICAN AMERICAN ADOLESCENT MALES IN ADVANCED SECONDARY MATHEMATICS

Adopting a critical race theory stance, this study examined the intersectionality of race, class, and gender and their influence on the educational outcomes of six African American males, who against the odds, have demonstrated success in advance secondary mathematics. Consistent with critical race theory, the purpose of the study was to create counter narratives that push back against dominant narratives about the academic abilities of African American males, specifically in mathematics. This study explored the ways in which this historically marginalized student group self-identify and communicate their social, cultural, emotional, and academic experiences and the development of strategies to navigate environments in which they are underrepresented. At the broadest level, the African American male participants individually and consistently addressed the following four themes in their semi structured interviews: (1) inequitable [institutional] practices rationalized by the dominant narrative, (2) caring and influential relationships, (3) early access to enriched and accelerated mathematics curricula, and (4) intrinsic and extrinsic motivators for success. First, the participants collectively spoke of a range of racialized and sometimes gendered barriers (e.g., teachers and peers who doubted the abilities of Black learners) that they faced as African American male learners of mathematics. Second, and in response to these racialized-gendered barriers, they each reported drawing on relationships and positive interactions with their parents, teachers, peers, and African American male role models. Third, all six participants communicated the value added of exposure to high quality schooling experiences to include early identification as strong mathematics students, enrollment in specialized schools and programs, early exposure to rigorous mathematics content, and active participation in extra/co-curricular opportunities. Fourth, and mediated by their relationships and early exposure to advanced mathematics, they all reported developing intrinsic and extrinsic motivations that sustained their success. In terms of the last point, and in their own ways, they were motivated, in part, to push back on dominant, racist narratives regarding the academic abilities of African American males as they navigated implicit racial bias from their teachers, peers, institutional practices, and the larger society

An experimental study examining the relationship between parenting behaviours, responsibility beliefs and obsessive-compulsive symptoms in nonclinical children and their mothers

Inflated responsibility (Salkovskis, 1985) is proposed as a central concept in understanding the development and maintenance of OCD. Salkovskis et al. (1999) proposed that inflated responsibility develops during childhood and parenting behaviours assume a significant role in the development of this cognitive vulnerability. The aim of this research was to investigate if parenting behaviours mediate the relationship between maternal responsibility beliefs and the development and maintenance of OCD like behaviours in their non-anxious children. Method This study used an experimental between-subjects design. 38 children aged 9–12 years were exposed to a high responsibility condition. Their mothers were randomly allocated to either a condition of inflated responsibility or no responsibility. During a sweet sorting task, maternal behaviours were coded for the constructs of warmth and control and the amount of reassurance giving was measured. In addition, the OCD like behaviours of the child were measured. State anxiety was measured pre and post task in mothers and their children. Results The results demonstrated that the experimental manipulation was not successful in increasing either maternal or child subjective responsibility beliefs. However, mothers in a condition of inflated responsibility demonstrated significantly less warmth when reading sorting instructions to their child and significantly more control during the sorting task than mothers in a condition of no responsibility. No significant differences were found in reassurance giving or maternal warmth during the task phase. Additionally, no significant differences were observed in child iii behaviours during the sorting task. State anxiety in both children and mothers reduced significantly from baseline to post task. Conclusions It is proposed that these findings suggest that the experimental manipulation did have an impact on maternal levels of control and warmth; however these differences were not strong enough in order to elicit an effect on children’s behaviours. Methodological considerations are considered. Clinical and theoretical implications are discussed and recommendations made for future research