Parallel Redundant Research Articles

Relationship between Uncertainty and Health-related Quality of Life in Elderly Patients Undergoing Total Knee Arthroplasty: The Mediating Effects of Sense of Coherence and Social Support

Purpose: The purpose of this study was to examine the mediating effects of sense of coherence and social support in the relationship between uncertainty and health-related quality of life (HRQoL) in elderly patients who underwent with total knee arthroplasty. Methods: A descriptive study was conducted with 186 patients who underwent total knee arthroplasty. Data were collected from September 17 to October 16, 2019 through structured questionnaires and analyzed with descriptive statistics, the independent t-test, one-way analysis of variance, Pearson correlation coefficients, and a parallel redundant mediated model in the PROCESS macro using SPSS version 27.0. Results: The mean scores of uncertainty, sense of coherence, social support, and HRQoL were 100.72, 49.77, 93.77, and 41.61. The direct effect of uncertainty on HRQoL and the indirect effect of uncertainty, mediated by sense of coherence and social support, on HRQoL were statistically significant. Conclusion: These results indicate that in order to increase the HRQoL of elderly patients who undergo total knee arthroplasty, it is necessary to develop an intervention program that focuses both on reducing uncertainty and on improving patients’ sense of coherence and social support.

A Note on the Time to Failure of a Two-Unit Parallel Redundant System with Deterioration on a Lattice

In this paper, we consider a two-unit parallel redundant system with deterioration on a lattice, where each unit has multi-stage deterioration levels, say, n levels. The transition from one deterioration level to the subsequent level occurs following the well-known Marshall-Olkin bivariate exponential distribution. We derive the closed form of the Laplace transform of the time to system failure in the two-unit parallel redundant system with deterioration on n×n lattice without repair and simultaneous failure, as well as the simple system on 3×3 lattice.

Effects of Anxiety on Health Related Quality of Life of the Elderly: Multiple Mediating Effects of Self-esteem and Social Support

Purpose: The purpose of this study was to examine the mediating effect of self-esteem and social support on the relationship between anxiety and health-related quality of life (HRQoL) in the elderly. Methods: The Korea adult psycho-social anxiety survey data were collected from August to September 2015 by the Korea Institute for Health. The subjects were 1,035 elderly people who were aged 65 or older at the time of the data survey. The data were analyzed by t-test, chi-square, Pearson correlation coefficient, and parallel redundant mediated model for PROCESS macro using SPSS 23.0. Results: They scored an average of 37.93±7.58 for anxiety, 28.59±3.45 for self-esteem, 17.25±4.11 for social support, and 0.88±0.11 for HRQoL. The direct effect of anxiety on HRQoL and the indirect effect of anxiety mediated with self-esteem and social support about HRQoL were statistically significant. Conclusion: These results indicate that in order to increase the HRQoL of the elderly, it is necessary to develop an intervention program that focuses not only on reducing anxiety but also on improving self-esteem and social support.

Product development resilience through set‐based design

AbstractOften during a system Product Development program, external factors or requirements change, forcing system design change. This uncertainty adversely affects program outcome, often adding to development time and cost, production cost, and can compromise system performance. We present a development approach that minimizes the impacts, by proactively considering the possibility of changes in the external factors and the implications of mid‐course design changes. The approach considers the set of alternative designs and the burdens of a mid‐course change from one design to another in determining the relative value of a specific design through the set‐based design methodology. The approach considers and plans parallel (redundant) development of alternative designs with progressive selection of options, including time‐versus‐cost tradeoffs and the impact change‐costs. The approach includes a framework of the development process addressing design and integration lead‐times, their relationship to the time‐order of design decisions, and the time‐dependent burden of design changes. We also compare set‐based and single point design schemes.

English

English

Applicability of the dielectric barrier discharge for helium ash measurements in the divertor region

Abstract Controlled fusion based on the magnetic confinement of the plasma is one of the main aims of the Euro-fusion programme. In the fusion device, the hydrogen isotopes, in nuclear reactions, will produce helium nuclei. The products, as the ash, will be removed from the plasma in the region of the so-called divertor. Controlling the helium to hydrogen ratio in this ‘exhaust gas’ will provide information about the efficiency of the fusion process as well as of the efficiency of the helium removal system. One of the methods to perform this task is to study the properties of the discharge conducted in such exhaust gas. In this paper, the applicability of the dielectric barrier discharge (DBD) is studied. This preliminary experiment shows a great potential in applicability of this kind of discharge. The optical as well as pulse-height spectra were studied, both revealing very promising properties. In the optical spectrum, one can observe well separated hydrogen and helium spectral lines, with intensities of the same order of magnitude. Moreover, in the registered spectral region, the molecular spectra are negligible. The pulse-height spectra reveal very distinct shape in helium and hydrogen. Checking of this spectrum could provide parallel (redundant) information about the partial pressure of helium in the magnetic confinement fusion (MCF) device exhaust gas.

Conserved roles for cytoskeletal components in determining laterality.

Consistently-biased left-right (LR) patterning is required for the proper placement of organs including the heart and viscera. The LR axis is especially fascinating as an example of multi-scale pattern formation, since here chiral events at the subcellular level are integrated and amplified into asymmetric transcriptional cascades and ultimately into the anatomical patterning of the entire body. In contrast to the other two body axes, there is considerable controversy about the earliest mechanisms of embryonic laterality. Many molecular components of asymmetry have not been widely tested among phyla with diverse bodyplans, and it is unknown whether parallel (redundant) pathways may exist that could reverse abnormal asymmetry states at specific checkpoints in development. To address conservation of the early steps of LR patterning, we used the Xenopus laevis (frog) embryo to functionally test a number of protein targets known to direct asymmetry in plants, fruit fly, and rodent. Using the same reagents that randomize asymmetry in Arabidopsis, Drosophila, and mouse embryos, we show that manipulation of the microtubule and actin cytoskeleton immediately post-fertilization, but not later, results in laterality defects in Xenopus embryos. Moreover, we observed organ-specific randomization effects and a striking dissociation of organ situs from effects on the expression of left side control genes, which parallel data from Drosophila and mouse. Remarkably, some early manipulations that disrupt laterality of transcriptional asymmetry determinants can be subsequently "rescued" by the embryo, resulting in normal organ situs. These data reveal the existence of novel corrective mechanisms, demonstrate that asymmetric expression of Nodal is not a definitive marker of laterality, and suggest the existence of amplification pathways that connect early cytoskeletal processes to control of organ situs bypassing Nodal. Counter to alternative models of symmetry breaking during neurulation (via ciliary structures absent in many phyla), our data suggest a widely-conserved role for the cytoskeleton in regulating left-right axis formation immediately after fertilization of the egg. The novel mechanisms that rescue organ situs, even after incorrect expression of genes previously considered to be left-side master regulators, suggest LR patterning as a new context in which to explore multi-scale redundancy and integration of patterning from the subcellular structure to the entire bodyplan.

Mean time to failure of systems with dependent components

We consider first a system of two components that are possibly dependent. Two simple reliability structures can be formed: series system and parallel (redundant) system. The exact formulas and two-sided bounds for the MTTF of systems are provided. We extend some of the results of Kotz et al. (2003) [8] on the effect of redundancy or competing risk when component lifetimes are no longer independent. The main results are illustrated by some useful distributions. The new (r,s)-out-of-n system is also discussed. In addition, a new concept of dependence ordering (more diagonal dependent) between bivariate distributions is introduced and used to compare the system lifetimes. Finally, the extension of the main results to the three-component systems and multi-component systems are also briefly investigated.

RELIABILITY ASSESSMENT FOR A FOUR CYLINDER DIESEL ENGINE BY EMPLOYING ALGEBRA OF LOGICS

In this paper, the authors have evaluated reliabili ty of four cylinder diesel engine by employing the Algebra of logics which is easier in comparison of old techniques. Here, a multi-comp onent fuel system in diesel engine, comprised of fo ur subsystems in series, has considered. The authors, in this model, have consid ered a parallel redundant fuel injective device to improve the system’s performance. The whole system can fail due to failu re of atleast one component of all the routes of flow. Boolean function technique has used to formulate an d solve the mathematical model. Reliability and M.T .T.F. of the considered diesel engine have been obtained to connect the model with physical situations. A numerical example and its g raphical representation have been appended at last to highlight important result s.

Economic analysis of an n-unit parallel redundant system based on a Stackelberg game formulation

A parallel redundancy has been researched in a great amount of literature on reliability theory. In the real circumstances, however, it is seldom observed except some systems that require much higher reliability. This is because most of the literature only look at the manufacturer’s point of view. The present study carries out an economic analysis of an n-unit parallel redundant system against a single unit system based on a Stackelberg game formulation considering both the consumer’s viewpoint and the manufacturer’s one. It clarifies quantitatively in what situation the manufacturer can increase his profit by dealing in the parallel redundant system.

Optimal Resource Allocation for Maximizing Performance and Reliability in Tree-Structured Grid Services

The paper considers a grid computing systems in which the resource management systems (RMS) can divide service tasks into execution blocks (EB), and send these blocks to different resources. To provide a desired level of service reliability, the RMS can assign the same EB to several independent resources for parallel (redundant) execution. According to the optimal schedule for service task partition, and distribution among resources, one can achieve the greatest possible expected service performance (i.e. least execution time), or reliability. For solving this optimization problem, the paper suggests an algorithm that is based on graph theory, Bayesian approach, and the evolutionary optimization approach. A virtual tree-structure model is constructed in which failure correlation in common communication channels is taken into account. Illustrative examples are presented.

Optimal service task partition and distribution in grid system with star topology

The paper considers grid computing systems in which the resource management systems (RMSs) can divide service tasks into execution blocks (EBs) and send these blocks to different resources. In order to provide a desired level of service reliability the RMS can assign the same blocks to several independent resources for parallel (redundant) execution. By the optimal service task partition into the EBs and their distribution among resources, one can achieve the greatest possible service reliability and/or expected performance. The paper suggests an algorithm for solving this optimization problem. The algorithm is based on the universal generating function technique and on the evolutionary optimization approach. Illustrative examples are presented.

Modelling and Control of a Parallel Redundant Manipulator with Hydraulic Actuators

The parallel robotic manipulator, MULTIPOD, is specially designed for carrying out drilling tasks in mines. It is based on two parallel three-degree-of-freedom mechanisms in serial connection. The structure that provides excellent stiffness is hydraulically driven and has six degrees of mobility. The pose of the end-effector is described by five degrees of freedom. In this paper, complete kinematic and dynamic analyses of the manipulator are carried out. In addition, a proportional controller equipped with hydraulic force feedback is designed for the robot. The simulated results that demonstrate the behaviour of the manipulator are presented in this paper.

An efficient heuristic for series–parallel redundant reliability problems

This paper presents a novel algorithm for solving a series–parallel redundancy allocation problem with separable constraints. The idea of a heuristic approach design is inspired from the greedy method and the genetic algorithm. The structure of the algorithm includes: (1) randomly generating a specified population size number of minimum workable solutions; (2) assigning components either according to the greedy method or to the random selection method; and (3) improving solutions through an inner-system and inter-system solution revision process. Numerical results for the 33 test problems from previous research are reported and compared. As reported in this paper, the solutions found by our approach are all better than or are in par with the well-known best solutions from the approach taken by previous solutions.

Stochastic programming models for general redundancy-optimization problems

This paper provides a unified modeling idea for both parallel and standby redundancy optimization problems. A spectrum of redundancy stochastic programming models is constructed to maximize the mean system-lifetime, /spl alpha/-system lifetime, or system reliability. To solve these models, a hybrid intelligent algorithm is presented. Some numerical examples illustrate the effectiveness of the proposed algorithm. This paper considers both parallel redundant systems and standby redundant systems whose components are connected with each other in a logical configuration with a known system structure function. Three types of system performance-expected system lifetime, /spl alpha/-system lifetime and system reliability-are introduced. A stochastic simulation is designed to estimate these system performances. In order to model general redundant systems, a spectrum of redundancy stochastic programming models is established. Stochastic simulation, NN and GA are integrated to produce a hybrid intelligent algorithm for solving the proposed models. Finally, the effectiveness of the hybrid intelligent algorithm is illustrated by some numerical examples.

Failure probability assessment of parallel redundant structures

Considered in the analysis are complex systems with parallel redundancy. The failure probability of such a system is assessed by the strength probabilistic properties of the structural elements. There is a finite number of parallel structural elements that provides the maximum possible reliability of the system. Parallel systems may fail by instantaneous growth of failed elements. The tendency to catastrophic failure depends on the element strength probability and overload. Calculated is the critical stress corresponding to the beginning of catastrophic failure of the parallel system. Weibull probability distribution is used for describing the structural element strength. The critical stress ranges from 50% to 95% of the mean single element strength; depends on the overload and probability distribution.

Multiple-goal kinematic optimization of a parallel spherical mechanism with actuator redundancy

A kinematic is presented that is fully parallel and actuator redundant. Actuator redundancy refers to the use of more actuators than are strictly necessary to control the mechanism without increasing the mobility. The uses of this form of redundancy include the ability to partially control the internal forces, increase the workspace, remove singularities, and augment the dexterity. Optimization takes place based on several objective functions. The kinematic dexterity, the forces present at the actuators, and the uniformity of the dexterity over the workspace are all investigated as potential objectives. Global measures are derived from each of these quantities for optimization purposes. Instead, optimization of several factors is done simultaneously by specifying a primary objective and minimum performance standards for the secondary measures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Reliability analysis of a biogas plant having two dissimilar units

A biogas system with two dissimilar production units is considered. Mathematical modelling is carried out for the system to calculate the reliability and mean time to system failure of the system. Two models (parallel redundant and standby redundant) are given. Formulation is done using a simple probabilistic approach and the supplementary variable technique. The problem is solved using simple methods for solving differential equations. Expressions for profit function are given.

4680761 Self diagnostic cyclic analysis testing system (CATS) for LSI/VLSI

A biogas system with two dissimilar production units is considered. Mathematical modelling is carried out for the system to calculate the reliability and mean time to system failure of the system. Two models (parallel redundant and standby redundant) are given. Formulation is done using a simple probabilistic approach and the supplementary variable technique. The problem is solved using simple methods for solving differential equations. Expressions for profit function are given.

Operational behaviour of a power plant consisting of three generators by B.F. technique

In this paper, a non-repairable parallel redundant complex system similar to a power plant has been studied. The object of the system is to supply power, from a power house having three generators connected in parallel redundancy, to a very critical destination, connected by cables and transformers. The availability and M.T.T.F. have been evaluated by using the Boolean Function (B.F.) technique. The failure times of the various components of the system follow arbitrary distributions. Numerical examples with graphs have also been given to highlight the availability and M.T.T.F. of the system at any time.