A tutorial on the CARE III approach to reliability modeling

The CARE 3 reliability model for aircraft avionics and control systems is described by utilizing a number of examples which frequently use state-of-the-art mathematical modeling techniques as a basis for their exposition. Behavioral decomposition followed by aggregration were used in an attempt to deal with reliability models with a large number of states. A comprehensive set of models of the fault-handling processes in a typical fault-tolerant system was used. These models were semi-Markov in nature, thus removing the usual restrictions of exponential holding times within the coverage model. The aggregate model is a non-homogeneous Markov chain, thus allowing the times to failure to posses Weibull-like distributions. Because of the departures from traditional models, the solution method employed is that of Kolmogorov integral equations, which are evaluated numerically

Validation Methods Research for Fault-Tolerant Avionics and Control Systems Sub-Working Group Meeting. CARE 3 peer review

A computer aided reliability estimation procedure (CARE 3), developed to model the behavior of ultrareliable systems required by flight-critical avionics and control systems, is evaluated. The mathematical models, numerical method, and fault-tolerant architecture modeling requirements are examined, and the testing and characterization procedures are discussed. Recommendations aimed at enhancing CARE 3 are presented; in particular, the need for a better exposition of the method and the user interface is emphasized

Validation Methods Research for Fault-Tolerant Avionics and Control Systems: Working Group Meeting, 2

The validation process comprises the activities required to insure the agreement of system realization with system specification. A preliminary validation methodology for fault tolerant systems documented. A general framework for a validation methodology is presented along with a set of specific tasks intended for the validation of two specimen system, SIFT and FTMP. Two major areas of research are identified. First, are those activities required to support the ongoing development of the validation process itself, and second, are those activities required to support the design, development, and understanding of fault tolerant systems

Skolem Functions for Factored Formulas

Given a propositional formula F(x,y), a Skolem function for x is a function \Psi(y), such that substituting \Psi(y) for x in F gives a formula semantically equivalent to \exists F. Automatically generating Skolem functions is of significant interest in several applications including certified QBF solving, finding strategies of players in games, synthesising circuits and bit-vector programs from specifications, disjunctive decomposition of sequential circuits etc. In many such applications, F is given as a conjunction of factors, each of which depends on a small subset of variables. Existing algorithms for Skolem function generation ignore any such factored form and treat F as a monolithic function. This presents scalability hurdles in medium to large problem instances. In this paper, we argue that exploiting the factored form of F can give significant performance improvements in practice when computing Skolem functions. We present a new CEGAR style algorithm for generating Skolem functions from factored propositional formulas. In contrast to earlier work, our algorithm neither requires a proof of QBF satisfiability nor uses composition of monolithic conjunctions of factors. We show experimentally that our algorithm generates smaller Skolem functions and outperforms state-of-the-art approaches on several large benchmarks.Comment: Full version of FMCAD 2015 conference publicatio

Ayurvedic Research - Certain Rational Understanding

From a pilot view through the Ayurvedic Research Scenario, One can see that there are five fields predominantly working upon this agenda. They are academic institutions, Private R and D units, Govt. Ayurvedic Research bodies, Govt. Non Ayurvedic Research bodies and international firms and establishments. But the deficiency in the utilization of outputs of all these works is, there is no concomitant, co-ordinated works and is without central regulations. The lack of co-ordination among these fields reduces the growth rate of our researches. One can’t deny the fact that several researches are having only an eagle eye to commercialise the name “Herbal” and to fill certain pockets. Research scholars with fundamental attitudes towards Ayurveda, are trying to substantiate whole ancient texts and this leads to unidirectional researches and there by satisfying certain hidden political agendas. Lack of productive researches in the fundamental principles will definitely lead to the deterioration of Ayurvedic popularity. Present study cover problems of present Ayurvedic Researches, need of coordinate perspective researching planning, need of multi centre researches with long term planning, need of negative studies in the development of science, need of adaptation of current research output in academic syllabus and curriculum

Investigation of complete and incomplete fusion in 7^{7}Li+124^{124}Sn reaction around Coulomb barrier energies

The complete and incomplete fusion cross sections for $^{7}$Li+$^{124}$Sn reaction were measured using online and offline characteristic $\gamma$-ray detection techniques. The complete fusion (CF) cross sections at energies above the Coulomb barrier were found to be suppressed by $\sim$ 26 \% compared to the coupled channel calculations. This suppression observed in complete fusion cross sections is found to be commensurate with the measured total incomplete fusion (ICF) cross sections. There is a distinct feature observed in the ICF cross sections, i.e., $\textit{t}$-capture is found to be dominant than $\alpha$-capture at all the measured energies. A simultaneous explanation of complete, incomplete and total fusion (TF) data was also obtained from the calculations based on Continuum Discretized Coupled Channel method with short range imaginary potentials. The cross section ratios of CF/TF and ICF/TF obtained from the data as well as the calculations showed the dominance of ICF at below barrier energies and CF at above barrier energies.Comment: 9 pages, 8 figure

Regulation of HPV16 E6 and MCL1 by SF3B1 inhibitor in head and neck cancer cells

ABT-737 inhibits the anti-apoptotic proteins B-cell lymphoma 2 (BCL-2) and BCL-X L. Meayamycin B switches the splicing pattern of myeloid cell leukemia factor 1 (MCL1) pre-mRNA. Specifically, inhibition of splicing factor 3B subunit 1 (SF3B1) with meayamycin B promotes the generation of the proapoptotic, short splicing variant (MCL1-S) and diminishes the antiapoptotic, long variant (MCL1-L). This action was previously associated with the cytotoxicity of meayamycin B in non-small cell lung carcinoma cell lines. ABT-737 induced apoptosis in response to an ablation of MCL1-L by meayamycin B. In this study, we further exploited this synergistic combination in head and neck squamous cell carcinoma (HNSCC), up to 90% of which overexpress MCL1 and BCL-X L. In a panel of seven HNSCC cell lines, the combination of meayamycin B and ABT-737 rapidly triggered a Bax/Bak-mediated apoptosis that overcame the resistance from HPV16-positive HNSCC against each agent alone. Both RT-PCR and Western blotting showed that meayamycin B up-regulated MCL1-S and down-regulated MCL1-L. Significantly, we discovered that SF3B1 was involved in the splicing of oncogenic HPV16 E6 to produce non-oncogenic HPV16 E6*, indicating that SF3B1 may inhibit HPV16-induced tumorigenesis

Survivability model for security and dependability analysis of a vulnerable critical system

This paper aims to analyze transient security and dependability of a vulnerable critical system, under vulnerability-related attack and two reactive defense strategies, from a severe vulnerability announcement until the vulnerability is fully removed from the system. By severe, we mean that the vulnerability-based malware could cause significant damage to the infected system in terms of security and dependability while infecting more and more new vulnerable computer systems. We propose a Markov chain-based survivability model for capturing the vulnerable critical system behaviors during the vulnerability elimination process. A high-level formalism based on Stochastic Reward Nets is applied to automatically generate and solve the survivability model. Survivability metrics are defined to quantify system attributes. The proposed model and metrics not only enable us to quantitatively assess the system survivability in terms of security risk and dependability, but also provide insights on the system investment decision. Numerical experiments are constructed to study the impact of key parameters on system security, dependability and profit