Reliability Function

A National Aeronautics and Space Administration (NASA) supported Reliability, Maintainability, and Availability (RMA) analysis team developed a unique RMA analysis methodology using cut set and importance measure analysis in order to comparison model proposed avionics computing architectures. In this paper we will present this efficient application of the RMA analysis methodology for importance measures that includes Reliability Block Diagram (RED) Analysis, Comparison modeling, Cut Set Analysis, and Importance Measure Analysis. We will also demonstrate that integrating RMA early in the system design process as a key to success by providing a fundamental decision metric supporting design selection. The RMA analysis methodology presented in this paper and applied to the avionics architectures enhances the usual way of predicting the need for redundancy based on failure rates or subject matter expert opinion. Using the REDs and the minimal cut sets, along with the Fussell-Vesely (FV) factors, importance measures are calculated for each functional element in the architectures [I]. This paper presents an application of the FV importance measures and presents an improved methodology for using importance measures in success space (instead of failure space) to compare architectures. These importance measures are used to determine which functional element would be most likely to cause a system failure, thus, quickly identifying the path to increase the overall system reliability by either procuring more reliable functional elements or adding redundancy . This application of the RMA analysis methodology, using RBD analysis, cut set analysis, and the importance measure analysis, allows the avionics design team to better understand and compare the vulnerabilities in each of the architectures, enabling them to address the deficiencies in the design architectures more efficiently, while balancing the need to design for optimum weight and space allocations.

We consider a Gelfand-Pinsker discrete memoryless channel (DMC) model and provide a strong converse for its capacity. The strong converse is then used to obtain an upper bound on the reliability function. Instrumental in our proofs is a new technical lemma which provides an upper bound for the rate of codes with codewords that are conditionally typical over large message dependent subsets of a typical set of state sequences. This technical result is a nonstraightforward analog of a known result for a DMC without states that provides an upper bound on the rate of a good code with codewords of a fixed type (to be found in, for instance, the Csiszár-Körner book).

The close resemblance of squamous papilloma with verrucous carcinoma and the chief etiological factor associated
with its development, the human papillomavirus (HPV) raises a doubt about its close association with malignancy.
The best way to treat HPV growths is surgical removal and assessment of lesion by histopathology. The defect needs
reconstruction with full function and aesthetic outlook. Thirty-seven years old young man with history of tobacco
chewing developed slow growing papilloma in upper lip in one year. It was excised fully and the defect was repaired
by arterialized lip vermilion mucosal flap based on slightly tortuous labial vessel and so the flap could be elastically
stretched even up to fifty percent of lip length and applied successfully. Same patient developed papilloma in lower
lip as a separate primary after two years of nonrecurrence of previous operated upper lip papilloma. Lower lip lesion
was excised similarly and repaired with same type of vermilion mucosal advancement flap from adjacent part of
lower lip defect created. The post-operative period was uneventful and after three years of last operation there is no
recurrence in either lip. Vermilion flap which is based on labial artery containing composite tissue comprising of
mucosa and portion of orbicularis muscle mainly has been utilized to reconstruct the post excision papilloma lip
defect with excellent functional and aesthetic results. There was no microstomia. It is single stage not involving donor
site like tongue or cheek mucosa and is good upto half of lower lip defects.

In this article is made an opening for the software reliability issues, through wide-ranging statistical indicators, which are designed based on information collected from operating or testing (samples). It is developed the reliability issues also for the case of the main reliability laws (exponential, normal, Weibull), which validated for a particular system, allows the calculation of some reliability indicators with a higher degree of accuracy and trustworthiness

The snowball sampling as network research presents numerous advantages in registering the "hidden populations", but also a major disadvantage -the absence of objective, numeric criteria for the decision of stopping the investigation. There is also a certain ambiguity about the volume of the investigated sample, which cannot be previously calculated, but is at the choice of the investigator to stop the research when he considers a satisfactory volume of information was accumulated. The purpose of this paper is to adopt the sequential method for the case of small-volume populations, a typical situation for the researches that require the snowball sampling method.

Although research with functional MR imaging of the brain has proliferated over the past 5 years, technical limitations, such as motion, chemical shift, and susceptibility artifacts, have impeded such research in the human spinal cord. The purpose of this investigation was to determine whether a reliable functional MR imaging signal can be elicited from the cervical spinal cord during simple motor activity. Subjects performed three different motor tasks that activate different segments of the spinal cord. Gradient-echo-planar imaging on a 1.5-T clinical unit was used to image cervical spinal cords of human subjects. Another group of subjects was imaged while performing isometric exercise to study the relationship between the blood oxygenation level-dependent (BOLD) signal and applied force. Task-dependent BOLD activity was detected in all subjects. Signal amplitude varied between 0.5% and 7%. Moreover, a linear relationship was found between the applied force and the signal amplitud...

The paper is structured in five parts. The first part looks at the reliability centered maintenance (RCM) on urban MV networks opportunity. Also here is presented the database utility for RCM implementation to urban MV networks. The second part is about the database structure and the informational support of database. The indicators evaluation and the intrinsic objective of RCM strategies implementation to urban MV electric networks make the subject of the third part .of the paper. The 4 part contains a brief presentation of the soft used for database administration and indicators assessment used for RCM strategy implementation to urban MV electric networks components. The conclusions and indications looking to urban MV electric network are presented in the last part of the paper. 1. PRELIMINARY APPRECIATION The reliability centered maintenance (RCM) is a well known method [1÷6] for it’s positive impact on costs decreasing and power services quality increasing. The urban power distr...

Analysis of earth dams is generally conducted in three stages of stability, deformability and water penetration analysis. Lack of sufficient attention to leakage, as one of the most important issues, leads to erosion and destruction of slope stability. The aim of current paper is to analyze the earth dam leakage with respect to the existing uncertainty in soil hydraulic parameters. In this research, the Monte Carlo (MC) method was used to calculate soil hydraulic parameters. Using these parameters, analysis of Alborz earth dam leakage by means of SEEP/W model based on the finite elements method was investigated. Due to the hydraulic conditions of the core soil, the total head value, pore water pressure, and water flux in core region will change. The results indicate that uncertainty in the hydraulic parameters of Alborz earth dam are significant, thus risk is important in this dam. The application of the proposed methodology in estimation of leakage from Alborz earth dam in Mazandaran province reveals its efficiency and proper accuracy in predicting the amount of leakage flow in earth dams with respect to the possible changes in the hydraulic parameters of the soil. Moreover, it was found that the quantity of seepage increases considerably when the dam is without core, therefore, the core is very necessary to decrease the value of seepage through the earth dam.

As already well known, Terna leads the Working Package 5 of The Italian demo of the H2020 Osmose project, which stands for Optimal System-Mix Of flexibility Solutions for European electricity. The main purpose of OSMOSE is developing a novel Energy Management System (EMS), which allows managing distributed Renewable Energy Sources (RES) and grid congestions, by properly coordinating innovative flexibility resources which include Dynamic Thermal Rating (DTR) and Demand Side Response (DSR). In this innovative approach, one of the two DTR investigated methods, which have been both developed by Ensiel, a consortium of Italian universities active in power systems research, is the Weather Based DTR. This technique is based on a thermo-mechanical model of the monitored line and on a detailed weather forecast of the involved area, having as final output the loadability curve of the line. The main features of the Weather Based DTR solution are described in this paper, and the first experimental results obtained on real case studies are presented and discussed in order to prove their effectiveness.

In this paper, we consider the residual lifetimes of surviving components of a failed coherent system with n independent and identically distributed components, given that before time t1 (t1 > 0), exactly r (r < n) components have failed and, at time t2 (t2 > t1) the system just failed. Some aging properties and preservation results of the residual lives of the surviving components of such systems are obtained. Also some examples and applications are given.

In this paper, we consider the residual lifetimes of surviving components of a failed coherent system with n independent and identically distributed components, given that before time t1 (t1 \u3e 0), exactly r (r \u3c n) components have failed and, at time t2 (t2 \u3e t1) the system just failed. Some aging properties and preservation results of the residual lives of the surviving components of such systems are obtained. Also some examples and applications are given

In this paper, we consider the residual lifetimes of surviving components of a failed coherent system with n independent and identically distributed components, given that before time t1 (t1 > 0), exactly r (r < n) components have failed and, at time t2 (t2 > t1) the system just failed. Some aging properties and preservation results of the residual lives of the surviving components of such systems are obtained. Also some examples and applications are given.

Suppose a subset of populations is selected from the given k gamma G(O~,p) (i = 1, 2,..., k) populations, using Gupta's rule (1963, Ann. Inst. Statist. Math., 14, 199-216). The problem of estimating the average worth of the selected subset is first considered. The natural estimator is shown to be positively biased and the UMVUE is obtained using Robbins' UV method of estimation (1988,

Content to be transported over an Information Centric Networking (ICN) infrastructure can be very variable in size, from few bytes to hundreds of gigabytes. Therefore it needs to be segmented in smaller size data units, typically called chunks, in order to be handled by ICN nodes. A chunk is the basic data unit to which caching and security (e.g. encryption and signature) functions are applied. If we consider the overhead and the number of cryptographic operations to be performed by nodes, a good choice for the chunk size would be from hundreds of KBs up to few MBs. However, if the chunk size is bigger than the Maximum Transfer Unit of a link, chunks will be fragmented. We show that if we have more than 3-4 fragments per chunk, and congestion and reliability functions are executed on a chunk by chunk basis, the efficiency of the congestion control algorithm drastically decreases. On the other side, a small chunk size would increase overhead and rate of signature checks. The contribution of this paper is twofold: 1) we propose to segment content in two levels: at the first level the content is segmented in chunks, at the second level the chunks are segmented into smaller data units, handled by an ICN specific Transport Protocol (ICTP), performing reliability and congestion control functions; 2) we propose to adopt a receiver-driven transport protocol, in which the receiver adjusts the sending rate to control congestion, we describe an implementation of this protocol, and evaluate its performance.

Game theory cannot be implemented successfully until practical models and the platform on which it can be simulated are explored. The applications of the game theory for various technical problems are introduced and a model for nanotechnology is developed. Recent applications of nanotechnology are considered for model development, with a focus on its application in companies wishing to implement nanotechnology in their future products. The implementation of such models is met by an HPC setup which is used for the developed game theory-based computations for the commercialization of nanotechnology. A classical game is defined depending on various parameters required to predict the rate of commercialization of a nano device. The rate of commercialization is developed and the gaming model is modelled with reference to the commercialization theory. Equilibrium cases pertaining to business in nano domains are studied and a proposal on the impact of various strategic profiles with the payoff is computed. This study is applicable in the study of nanotech wars which may resort to extensive use of nano materials. It can also be used for the estimation of time taken for the commercialization of a nano device. The strategy of a company for the commercialization and implementation of a novel nano device can be affected by other companies' efforts to do the same; therefore, the need of strategic decision-making emerges. In such strategic conditions, the model may assists companies in their decision-making. In this case, the modelling complexity increases; this aspect has been addressed and the modelling was simplified seeking for a better understanding of the phenomenon.

We have developed a library for simulation of DC traction system. The modeling, installation and reliability aspects of Traction system in purview of current developments in HPC and Virtual reality can be implemented on the proposed protocol. We have proposed a model to predict and analyze traction system more comprehensively and put a modeling structure regarding the same. Distribution of various computations is shown in an HPC setup and has been implemented. The advantages of Virtual reality in installation in city and intercity, driving has been implemented on C#. Installation of VR framework for installation of DC traction thus has been implemented in the current technologies that are being developed in areas of HPC and VR.

In this paper we have reviewed the development in CUDA and the implementation of various distribution that exists in the reliability for MEMS based devices on a CUDA setup. The various distributions can be highly optimized so that the system can be simulated highly on CUDA. We have shown the type of distribution may vary from exponential to binomial to other that are being proposed recently. The Reliability modeling codes to calculate reliability function, failure rate function, Mean time to failure (MTTF) and Mean Residual time (MRT) are proposed for MEMS technology for these specific calculations needs to be performed for which CUDA plays a very important role. It is observed that High Performance Computing (HPC) can be used to optimize reliability calculation and help to accelerate research in reliability of MEMS. The three key abstractions of CUDA i.e. hierarchy of thread groups, shared memories, and barrier synchronization are exposed as a set of extensions to C language, which provides fine-grained data parallelism and thread parallelism, nested within coarse-grained data parallelism and task parallelism. The key is division of the computations of Reliability analysis into crude sub-problems that can be solved parallely in isolation independently, and then into finer pieces that can be executed in parallel with mutual cooperation among them. Allowing threads to solve each sub-problem cooperatively, this division of problem preserves expressivity of language. Each sub-problem is thus scheduled to be solved on any of the available processor cores allowing transparent scalability. Thus computations of Reliability analysis can be performed by using a compiled CUDA program that can execute on any number of GPU cores. During the programming we need not know the exact configuration and thus only the runtime system needs to know the physical processor count.

We have implemented multifarious aspects of nano simulation using multi scale modeling on various HPC (High Performance Computing) setups. Distribution of jobs from macro to nano scale has been shown which holds the essence of simulation at nano scale. This distribution is substantiated on MPI (Message Passing Interface) and PVM (Parallel Virtual Machine) on MATLAB, Linux and WCCS (Windows Compute Cluster Server) environments. In this paper we have shown the connections and a novel way of implementing multi scale computations on an HPC setup. We have also compared the implementation of MPI and PVM based HPC setup for MATLAB, Linux and WCCS environments. The selection criteria for identification and proposition of the tool, protocol and environment for an HPC setup plays an important role in deciding the tool to be used. Comparison of the advantages and disadvantages of each of the methodologies being put forward. MPI.NET was used under WCCS where C# was used. The latest versions were used for PVM Linux based setup where Open SUSE Linux was used as the operating system. The main two criteria user friendly and performance were compared and the recommendations are made for making the right balance between them.

Abstract. Modern Computational methods have brought powerful techniques to calculate reliability by multi scale modeling supported by experimental and classical theoretical methods. These approaches play an im-portant role in Micro Electro Mechanical Systems (MEMS) ...

We consider a finite state Markov chain whose state space is partioned in two sets, E 0 and E 1 , and define a cycle as being constituted by a sojourn period in E 0 and another one in E 1 . We characterize the bivariate sequences of sojourn times in and passage times into E 0 (E 1 ) and states visited at entrance times into E 0 (E 1 ), along with the sequence of cycle durations and the states visited at the beginning of cycles. We derive bivariate probability generating matrix functions of sojourn times in E 0 and E 1 , and of cycle durations. Using these, we obtain expressions for moments of sojourn times in E 0 and E 1 , and of cycle durations, including their expected values, variances and covariances. Stationary versions of the Markov chain are also discussed. The derived results are illustrated in a variant of the success runs for Bernoulli trials setting, where changes between two different success probabilities are allowed. The analysis shows that non-negligible correlations between sojourn times in a set of states and between cycle durations may arise, as illustrated through the considered example.

Flexibility in shape and scale of Burr XII distribution can make close approximation of numerous well-known probability density functions. Due to these capabilities, the usages of Burr XII distribution are applied in risk analysis, lifetime data analysis and process capability estimation. In this paper the Cross-Entropy (CE) method is further developed in terms of Maximum Likelihood Estimation (MLE) to estimate the parameters of Burr XII distribution for the complete data or in the presence of multiple censoring. A simulation study is conducted to evaluate the performance of the MLE by means of CE method for different parameter settings and sample sizes. The results are compared to other existing methods in both uncensored and censored situations.

Variable feed machining has recently been proposed as a significant method to improve cutting tool life particularly for hard and diffucult to machine materials. This method, which is easy to apply in industry, has been shown to improve tool life in the order of 40% in certain cases. This paper presents a reliability model for the quantitative study of the effect of feed variation on tool wear and tool life. To better compare processes with two different wear modes, a reliability model taking simultaneously into account both flank and face wear has been developed. With this model, which is based on experiments, the tool life for the constant and variable feed cases was calculated from the reliability function. The mean time to failure, obtained from the reliability function, provides an accurate evaluation for any probabilistic distribution. The proposed method is therefore a general approach that can be used for analyzing cutting tool life under any conditions and for any equipment and material.

This paper deals with the use of Open Source Software (OSS) in learning environments. Advantages and obstacles of OSS are discussed. Problems and opportunities of introducing OSS into an educational process especially in primary and secondary schools are presented. The survey research, which was carried out in order to study the use of OSS in the educational system of Slovenia is described. The most important characteristics of OSS like reliability, functionality, interoperability, licensing philosophy, values of OS movements and price are examined. The results are presented and compared with those of a similar research in USA. Some interesting similarities and differences are discovered. Povzetek: Prikazani so rezultati raziskave o uporabi odprte kode v slovenskih osnovnih in srednjih šolah.

This article deals with the use of Open Source Software (OSS) at the primary and secondary level of education in Slovenia. The challenges and advantages of using OSS in educational processes are discussed. The main advantages of OSS are: economic freedom, stability, reliability and a possibility of making modifications but -on the other hand -the main problem for schools can be installation and support. The research carried out to determine the use of OSS in schools is described and the results are compared with the results of similar research studies in Germany, Sweden and UK. The results of both surveys show, that Linux and OpenOffice.org are the most popular OSS applications on computer desktops. The most important conclusion (according to our research) is that lack of knowledge prevents a faster introduction of OSS in education.

This paper introduces a new four parameter Rayleigh distribution which generalizes the transmuted generalized Rayleigh distribution introduced by Merovci (2014). The new model is referred to as exponentiated transmuted generalized Rayleigh (ETGR) distribution. Various mathematical properties of the new model including ordinary and incomplete moments, quantile function, generating function and Rényi entropy are derived. We proposed the method of maximum likelihood for estimating the model parameters and obtain the observed information matrix. Two real data sets are used to compare the flexibility of the new model versus other models.

Simple T cell assays specific for any chosen HLA class I or class II/peptide combination, are of enormous value in cancer immunotherapy, clinical trials, vaccine and infectious disease research. The reliable measurement of T cell activity can be difficult due to the presence of other alleles on target cells, particularly for the non-HLA-A2 alleles, and the varying baseline characteristics of the different APCs employed. In the absence of pulsing with HLA-A2 restricted peptides, T2 cells are functionally HLA class I and II negative. By coating these cells with recombinant HLA peptide complexes, HLA mono-specific cells are produced that present only a defined single epitope, and generate minimal background immune activation. In ELISPOT, intracellular cytokine staining (ICS) and killing assays using T cells specific for HLA-A2/peptide complexes, the HLA mono-specific cells gave comparable results, to those using standard peptide pulsed HLA-A2 positive T2 cells without significant background. Successful T cell assays for non-HLA-A2 T cells were also performed, with PBMCs recognizing HLA-A24 and HLA-DR15/ peptide complexes. The data, obtained with ELISPOT, ICS and FACS-based killing assays, all demonstrate high specificity of T cell activity and low levels of background activity. HLA monospecific cells are simple to prepare, and can be used with any stable recombinant HLA allele/ peptide combination; providing a useful system for improved T cell functional analyses across all HLA allotypes. This represents a significant advance in the generation of reliable functional T cell data.

In a remarkable paper published in 1976, Burnashev determined the reliability function of variable length block codes over a discrete memoryless channel with feedback by providing a lower bound to the expected decoding time in terms of the size of the message set and the probability of error. We offer an alternative derivation of this lower bound. This derivation is simpler than the original and relates the quantities that appear in the bound to uncertainty reduction and binary hypothesis testing. Furthermore, the derivation closely parallels that of an upper bound by Yamamoto and Itoh.

We introduce the entropy function in order to study the reliability and repairability of systems. In detail we establish the explicit relationships between reliability and repairability; then we calculate the decay of a system due to its regular running.

In this paper, the evaluation of reliability function, Vesely-Fussell measure of component importance and Birnbaum reliability measure of component importance in a consecutive-k-out-of-n:F system and a consecutive-k-out-of-n:G system are considered. Using the minimal cut (path) sets of a consecutive-k-out-of-n:G(F) system, we present nonrecursive algorithms for determining the system reliability and measures of component importance of these systems. We show that these algorithms leads to explicit formulas for determining the reliability function and measures of component importance in a k-out-of-n:F system with independent but not identical components.