Automated Synthesis of SEU Tolerant Architectures from OO Descriptions

SEU faults are a well-known problem in aerospace environment but recently their relevance grew up also at ground level in commodity applications coupled, in this frame, with strong economic constraints in terms of costs reduction. On the other hand, latest hardware description languages and synthesis tools allow reducing the boundary between software and hardware domains making the high-level descriptions of hardware components very similar to software programs. Moving from these considerations, the present paper analyses the possibility of reusing Software Implemented Hardware Fault Tolerance (SIHFT) techniques, typically exploited in micro-processor based systems, to design SEU tolerant architectures. The main characteristics of SIHFT techniques have been examined as well as how they have to be modified to be compatible with the synthesis flow. A complete environment is provided to automate the design instrumentation using the proposed techniques, and to perform fault injection experiments both at behavioural and gate level. Preliminary results presented in this paper show the effectiveness of the approach in terms of reliability improvement and reduced design effort

On applying the set covering model to reseeding

The Functional BIST approach is a rather new BIST technique based on exploiting embedded system functionality to generate deterministic test patterns during BIST. The approach takes advantages of two well-known testing techniques, the arithmetic BIST approach and the reseeding method. The main contribution of the present paper consists in formulating the problem of an optimal reseeding computation as an instance of the set covering problem. The proposed approach guarantees high flexibility, is applicable to different functional modules, and, in general, provides a more efficient test set encoding then previous techniques. In addition, the approach shorts the computation time and allows to better exploiting the tradeoff between area overhead and global test length as well as to deal with larger circuits

A Test of the Rational Expectations Hypothesis using data from a Natural Experiment

Data on contestants' choices in Italian Game Show Affari Tuoi are analysed in a way that separates the effect of risk attitude (preferences) from that of beliefs concerning the amount of money that will be offered to contestants in future rounds. The most important issue addressed in the paper is what belief function is actually being used by contestants. The parameters of this function are estimated freely along with the parameters of a choice model. Separate identification of the belief function and preferences is possible by virtue of the fact that at a certain stage of the game, beliefs are not relevant, and risk attitude is the sole determinant of choice. The rational expectations hypothesis is tested by comparing the estimated belief function with the "true" offer function which is estimated using data on offers actually made to contestants. We find that there is a significant difference between these two functions, and hence we reject the rational expectations hypothesis. However, when a simpler "rule-of-thumb" structure is as- sumed for the belief function, we find a correspondence to the function obtained from data on actual offers. Our overall conclusion is that contestants are rational to the extent that they make use of all available relevant information, but are not fully rational because they are not processing the information in an optimal way. The importance of belief-formation is confirmed by the estimation of a mixture model which establishes that the vast majority of contestants are forward-looking as opposed to myopic.Beliefs, Discrete choice models, Method of simulated likelihood, Natural Experiments, rational expectations, risky choice

Risk attitude in real decision problems

Experimental economics focuses on eliciting preferences, studying individuals one at a time to take into account their heterogeneity. Experiments have the appealing property of collecting enough observations to perform such an analysis. In real word, and in natural experiments, individuals cannot be observed according to experimenters’ needs. We propose a method that aggregates over individuals taking into account their heterogeneity. Using data from a natural experiment, we estimate three models of decision making under risk: Expected Utility, Rank-Dependent Expected Utility and Regret-Rejoice. Our results show that individual-wise analyses can be substituted by pooled approaches without losing information about individual heterogeneity.Experimental economics focuses on eliciting preferences, studying individuals one at a time to take into account their heterogeneity. Experiments have the appealing property of collecting enough observations to perform such an analysis. In real word, and in natural experiments, individuals cannot be observed according to experimenters’ needs. We propose a method that aggregates over individuals taking into account their heterogeneity. Using data from a natural experiment, we estimate three models of decision making under risk: Expected Utility, Rank-Dependent Expected Utility and Regret-Rejoice. Our results show that individual-wise analyses can be substituted by pooled approaches without losing information about individual heterogeneity

On integrating a proprietary and a commercial architecture for optimal BIST performances in SoCs

This paper presents the integration of a proprietary hierarchical and distributed test access mechanism called HD2BIST and a BIST insertion commercial tool. The paper briefly describes the architecture and the features of both the environments and it presents some experimental results obtained on an industrial So

Rapid maxillary expansion and upper airway morphology: a systematic review on the role of cone beam computed tomography

OBJECTIVE: This study aimed to investigate the quality of cone beam computed tomography (CBCT) studies evaluating the effects of rapid maxillary expansion on upper airway morphology. MATERIALS AND METHODS: A database search was conducted using PubMed, Ovid, and Cochrane Library up to December 2016. Studies in which CBCT was adopted to visualize the upper airway before and after rapid maxillary expansion were included. The population target was growing patients. Methodological quality assessment was performed. RESULTS: The screening process resulted in the exclusion of 1079 references, resulting in only 9 remaining papers that fulfilled the inclusion criteria. No randomized clinical trials were found. The quality scores ranged from 36% to 68% of the maximum achievable, and the mean quality score of the studies was 50%. No good quality studies were detected in our sample. CONCLUSIONS: Inconsistencies in the CBCT protocols utilized were detected between studies. Head posture, tongue position, and segmentation protocols were not consistent. These discrepancies were reflected in the different results obtained in the studies. A valid and consistent protocol with regard to head and tongue positioning, as well as nasal cavity volume segmentation, is required

Okada Purifying Therapy in combination with duloxetine vs. duloxetine alone in patients with TMD and fibromyalgia: a randomized clinical study

Abstract Objectives This randomized study was aimed at evaluating the additional analgesic effect of Okada Purifying Therapy (OPT) when administered in combination with duloxetine in patients with Temporomandibular Disorders (TMDs) and Fibromyalgia (FM). Methods Patients with TMDs visited at Department of Oral and Maxillofacial Sciences, Sapienza University of Rome who were diagnosed with FM were selected for the study. The final sample was composed of 31 patients: 15 patients were treated only with duloxetine (Group I) and 16 patients underwent also OPT treatment (Group II), for eight weeks. Craniomandibular index, total tenderness score, Brief Pain Inventory Modified Short Form, Fibromyalgia Impact Questionnaire, Beck Depression Inventory and State and Trait Anxiety Inventory-1 were assessed at the beginning (T0), during the course (T1) and after therapy (T2). Descriptive and inferential statistics were performed. Results In all the data analyzed, both groups showed an improvement in particular between T0 and T1. No statistically significant differences were observed between the two groups during the trial, except for the interaction between treatment and time as to the ability of walking at the BPI-I (F=7.57, p=0.002). No side effects due to the duloxetine were recorded in group II compared to group I. Conclusion The additional complementary treatment (OPT) did not appear to give the patients with TMDs and FM any further benefit but it might improve pharmacological tolerability of the traditional medication

A Multiphysics Co-Simulation Framework of a Gas Engine and Three-Way Catalyst toward a Complete Vehicle Design Model

In view of the increasingly stringent emission regulations, the automotive sector needs considerable support from the development of robust and reliable engine and aftertreatment models. Accurate reproduction of engine-out and tailpipe pollutants plays a crucial role in complying with these legislations. Given the difficulty in characterizing some critical phenomena, frequently caused by strong dynamics and related to experimental uncertainties, communication between several calibrated and reliable models is mandatory. This is certainly valid for powertrains that will be powered with alternative gas fuels such as natural gas, bio-methane and hydrogen in the future. This paper describes a methodology to co-simulate a 1D CNG HD 6-cyl engine model and a 1D quasi-steady three-way catalyst model in a global framework for high-fidelity virtual prototyping of the vehicle system. Through the implementation of a dedicated control logic in MATLAB/Simulink, the modeling architecture allows for the reproduction of the engine performance parameters together with the evaluation of the TWC pollutants’ conversion efficiency. An extensive database of experimental tests was used to assess the model response. The latter was validated in multiple steady-state operating conditions of the engine workplan. Using a semi-predictive combustion model, the validation was carried out over a wide range of different air-to-fuel ratios and during fast rich/lean transitions to evaluate the formation and conversion phenomena of the main chemical species, both engine-out and tailpipe. Subsequently, the complete model was validated in dynamic conditions throughout a WHTC, accurately reproducing the cut-off phases and their sudden accelerations. The numerical–experimental agreement on pollutant reproduction is generally good and globally below 3%. Larger deviations occur in extremely rich conditions and in CH4 emission evaluation due to the lack of information related to the combustion process and chemical mechanisms involving the Pd surface

An effective distributed BIST architecture for RAMs

The present paper proposes a solution to the problem of testing a system containing many distributed memories of different sizes. The proposed solution relies in the development of a BIST architecture characterized by a single BIST processor, implemented as a microprogrammable machine and able to execute different test algorithms, a wrapper for each SRAM including standard memory BIST modules, and an interface block to manage the communications between the SRAM and the BIST processor. Both area overhead and routing costs are minimized, and a scan-based approach allows full diagnostic capabilities of the faults possibly detected in the memories under test