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The present study explored district-wise monthly rainfall of two climatic regimes (1960–1990 and 1991–2020) of the West Bengal state of India, which receives an annual rainfall of about 1500 mm with huge seasonal rainfall variability. A simple time series analysis does not show any noticeable trend. However, decomposing rainfall parameters into several indicators may explore the change. From this perspective, the present paper intends to explore the nature, degree, and direction of rainfall alteration. The range of variability approach (RVA) considered 29 indicators was adopted for unveiling it. RVA explored that in the 1991–2017 phase, the rainfall failure rate above the upper threshold (75th percentile) is 33% which is 10% greater than in 1961–1990. Seasonal variation in failure rate was detected, but overall larger area of the state recorded failure rate (FR) above the threshold. This result leads to increasing wetness conditions. Very low to moderate (< 0.4) degree of impact of rainfall alteration (DIRA) was found in the recent period. The areal occupation of moderate DIRA was considerable in pre-monsoon, post-monsoon, and winter seasons. Time series rainfall data-based flow duration curves (FDCs) indicated the dominance of the eco-surplus rainfall state over greater parts of the state (72–84%) in all the seasons except winter (49%). Such surplus rainfall may be beneficial to the ecological and agricultural perspective of the state. [ABSTRACT FROM AUTHOR]

The double sampling plan (DSP) is a generalized version of the single sampling plan (SSP) that provides several advantages, such as reduced sample size, increased discriminatory power, and better communication between producers and consumers. This study proposes a DSP for truncated life tests (TLT-DSP) using a two-parameter Lindley distribution. The proposed TLT-DSP's parameters are determined by a mathematical model designed to minimize the average sample number while fulfilling two constraints related to predefined quality levels and tolerated risks. Performance measures of the sampling plans are investigated to evaluate and compare their efficiency and effectiveness. Our results demonstrate that the proposed DSP is more efficient than the traditional SSP, especially in cases where the lot's quality is excellent or poor, and provides necessary protection to both parties involved. Additionally, two examples are presented, discussed and illustrated through a graphical user interface designed to validate the practicability of the proposed approach. [ABSTRACT FROM AUTHOR]

Objective: To compare between lower permanent retainers placed in the middle of the incisal third and retainers placed in the middle of lower incisors in terms of gingival condition, lower incisors stability and retainers’ failure rate. Materials and methods: This is a split-mouth clinical trial. Fifty patients finished fixed orthodontic treatment and required fixed permanent retainer in the lower arch were recruited. A multistranded (0.0215 inch) retainer, with a vertical step in the midline placing half of the retainer in the incisal third and the other half in the middle of the lower incisors was attached to all the teeth in the lower labial segment. After one year, all the subjects were recalled. The primary outcome was to evaluate the plaque index (PI) and the gingival index (GI) of the lower labial segment teeth. The secondary outcome was to assess retainers’ failure rate and the relapse in lower labial segment alignment. Results: The GI and the PI scores were significantly smaller on the side where the retainer was placed incisally (P = 0.004, P < 0.001, respectively). There was no statistical difference in the average Irregularity Index (IRI) and the retainer’s failure rate between the two sides (P = 0.52, P = 0.76, respectively). Conclusion: Placing lower fixed retainers in the incisal third will improve the lower labial segment oral hygiene and gingival health in the lingual area without affecting the efficiency or the integrity of the retainers. This trial was not registered Null Hypothesis: Placing the lower permanent retainer in the middle of the lingual surfaces of the lower labial segment’ teeth or in the incisal third will not affect the gingival health of the lower incisors. [ABSTRACT FROM AUTHOR]

This article examines the research carried out regarding the failure rate in electricity distribution systems. It introduces a comprehensive framework for managing failure rates in power distribution systems. This framework highlights that studies on failure rates in power distribution systems can be categorized into three distinct groups: modifying asset management activities in order to reduce failure rate, evaluate and control threats and risks, emergency measures after failure. In this article, all the studies conducted on the failure rate of electricity distribution systems are listed and presented, and categorized in the form of a comprehensive and conceptual framework. The relation of each category with the failure rate is explained and by studying the process of studies, the research gaps and the roadmap of future studies in the field of failure rate in electricity distribution systems are determined. [ABSTRACT FROM AUTHOR]

Introduction: Despite modern fixation techniques, spinopelvic fixation failure (SPFF) after adult spinal deformity (ASD) surgery ranges from 4.5 to 38.0%, with approximately 50% requiring reoperation. Compared to other well-studied complications after ASD surgery, less is known about the incidence and predictors of SPFF. Aims/objectives: Given the high rates of SPFF and reoperation needed to treat it, the purpose of this systematic review and meta-analysis was to report the incidence and failure mechanisms of SPF after ASD surgery. Materials/methods: The literature search was executed across four databases: Medline via PubMed and Ovid, SPORTDiscus via EBSCO, Cochrane Library via Wiley, and Scopus. Study inclusion criteria were patients undergoing ASD surgery with spinopelvic instrumentation, report rates of SPFF and type of failure mechanism, patients over 18 years of age, minimum 1-year follow-up, and cohort or case–control studies. From each study, we collected general demographic information (age, gender, and body mass index), primary/revision, type of ASD, and mode of failure (screw loosening, rod breakage, pseudarthrosis, screw failure, SI joint pain, screw protrusion, set plug dislodgment, and sacral fracture) and recorded the overall rate of SPF as well as failure rate for each type. For the assessment of failure rate, we required a minimum of 12 months follow-up with radiographic assessment. Results: Of 206 studies queried, 14 met inclusion criteria comprising 3570 ASD patients who underwent ASD surgery with pelvic instrumentation (mean age 65.5 ± 3.6 years). The mean SPFF rate was 22.1% (range 3–41%). Stratification for type of failure resulted in a mean SPFF rate of 23.3% for the pseudarthrosis group; 16.5% for the rod fracture group; 13.5% for the iliac screw loosening group; 7.3% for the SIJ pain group; 6.1% for the iliac screw group; 3.6% for the set plug dislodgement group; 1.1% for the sacral fracture group; and 1% for the iliac screw prominence group. Conclusion: The aggregate rate of SPFF after ASD surgery is 22.1%. The most common mechanisms of failure were pseudarthrosis, rod fracture, and iliac screw loosening. Studies of SPFF remain heterogeneous, and a consistent definition of what constitutes SPFF is needed. This study may enable surgeons to provide patient specific constructs with pelvic fixation constructs to minimize this risk of failure. [ABSTRACT FROM AUTHOR]

Electric power utilities are striving to address critical challenges such as energy consumption, material recovery, e-waste, procurement, and supplier working conditions. Currently, they are converting their old infrastructure into smart grids. The installation of smart meters is a key step in this process. Since a smart meter is an intelligent and modern measuring device that includes computer-aided measurements while also allowing intelligent management and determination of residential and industrial users' energy consumption and supply, their deployment in smart grids is of major importance. In this study, considering that the estimated number of smart meter units will be 188.12 million units by 2025, five different types of smart meters are used to estimate their failure behavior. We adopted the probability of smart meters' survival, considering the number of the components included in their PCBs, while the influence of their components follows an exponential distribution for a given lifetime. The meaning of the "fair" smart meter is introduced to solve critical concerns such as energy use, material consumption, e-waste, supplier sourcing, and labor conditions. To achieve the above targets, a circular economy chain analysis is implemented by dismantling the existing smart meters, classifying their materials into five primary groups and weighing them to obtain average values. Moreover, we calculate the average cost of the components using their equivalent market value as provided by stock markets to get the average weight of each component in terms of material cost. Finally, we introduce the "remanufacturing index" and the "reusing index" indices as procedure metrics to further quantify the circular economy chain results. The results show that the percentage of the reusing procedure in the "fair" smart meter circular economy chain is greater than the corresponding percentage of the remanufacturing procedure, while the percentage of the recycling procedure is increased as the recycling cost per unit, is also increased. [ABSTRACT FROM AUTHOR]

The ocean thermal energy conversion (OTEC) systems, as renewable energy-based power plants, have the potential to play a significant role in meeting future electricity demands due to the vast expanse of the world's oceans. These systems employ the temperature difference between surface ocean waters and deep ocean waters to drive a thermodynamic cycle and produce electricity. The temperature of deep ocean waters, approximately 1000 m below the surface, is approximately 4 °C, while surface ocean temperatures typically range between 20 and 30 °C. The generated power of OTEC systems is dependent on these temperature differences and may vary with changes in surface ocean temperatures. In this study, the main focus is to find the impact of temperature variation on the failure rates of OTEC system components and the generated power output of these plants. The findings indicate that as the demand for the power system increases, its reliability decreases. In order to improve the reliability of the power system, the integration of a new generation unit, such as the close cycle OTEC power plant under investigation, could be necessary. The findings also indicate the importance of considering temperature variation in the evaluation of the reliability of such types of power plants based on renewable energy. [ABSTRACT FROM AUTHOR]

Stop production and overhaul is an annual work of LNG (Liquefied Natural Gas) plant. However, the shutdown maintenance work under different market conditions needs comprehensive allocation of resources to achieve the purpose of economy, speed and safety. In order to study the fault situation of pneumatic valve, targeted maintenance work is carried out. In this paper, a workflow of DGM(1, 1) prediction model of grey system and sampling inspection method is proposed. With the help of DGM(1, 1) to predict the universality of "poor information and small sample" and the partial detection method of sampling inspection, the expected engineering purpose is achieved. The research results are as follows: (1) The failure situation of pneumatic valve in LNG plant from 2015 to 2020 is brought into the model to compare the actual value and predicted value in 2020, and the residual error is between 0.92 and 3, which indicates that the predicted result of the model is reliable. It is predicted that the comprehensive failure rate will remain at around 18% in 2021 and 2022. Next, we can continue to use DGM(1, 1) model to analyze the redundancy of actuator measurable signals. Make full use of the field known data, construct the functional relationship of measurable variables of actuators, realize on-line real-time judgment of actuator faults, and dynamically predict the failure rate of parts. (2) For maintenance work, 130 pneumatic valves need to be dismantled, with emphasis on the inspection of three components such as drive gas filter, electromagnetic valve and actuator. If the damage number is found to be less than or equal to 4, production can continue after the spare parts are repaired and replaced, otherwise, total inspection is required. In the next step, the relationship between valve distribution position and parts damage frequency should be counted, and the damage frequency should be reduced by strengthening sealing and changing installation methods. [ABSTRACT FROM AUTHOR]

This paper presents a new joint production, maintenance and quality control chart for a manufacturing system subject to random failure and produces both conforming and non-conforming products. The degradation of the manufacturing unit increases with the production rate and the time of its use, which affects its reliability and the product quality. The purposed joint policy aims to establish, firstly, the optimal plan of production during finite horizon that satisfies random demand under a given service level. and secondly, to determine simultaneously the optimal number of imperfect preventive maintenance actions at each production cycle, and the optimal control chart parameters for appropriate quality monitoring in the presence of assignable causes. Furthermore, rework activity is proposed for a fraction of the non-conforming products, which are detected in the presence of assignable causes, in order to improve their quality and sold as a second-rate product. The proposed optimization model minimises the average total costs including production, reworking, storage, rejection, quality and maintenance. Numerical examples and sensitivity analyses are presented to show the effectiveness of the proposed joint approach. [ABSTRACT FROM AUTHOR]

Ensuring the reliability of the functioning of MEMS devices is the most important task facing developers. Due to the variety of designs and materials used in MEMS devices, various failure mechanisms can occur. Most of these devices contain moving parts of the structure. The fatigue properties of the structural materials used and their aging under prolonged repetitive cyclic loading can lead to failure, which directly affects the reliability of the device. In this paper the fatigue properties and reliability of the sensitive element (SE) of a micromechanical accelerometer (MMA) sandwich structure of a capacitive type made of silicon under the conditions of the mechanism of fatigue failure of the material are analyzed. The number of cycles of periodic exposure for the occurrence of a failure and the failure rate of SEs are calculated. The crystallographic orientation of the surface plane of silicon—the SE material—is considered. The simulation results show that the fatigue life of SE of an MMA made of silicon can be sufficiently strong for general purpose applications. [ABSTRACT FROM AUTHOR]

Introduction: Most adult cases of bacterial–septic–arthritis of a native joint are effectively managed with a single surgical debridement, but some cases may require more than one debridement to control the infection. Consequently, this study assessed the failure rate of a single surgical debridement in adults with bacterial arthritis of a native joint. Additionally, risk factors for failure were assessed. Materials and Methods: The review protocol was registered on PROSPERO (CRD42021243460) before data collection and conducted in line with the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' (PRISMA) guidelines. Multiple libraries were systematically searched to identify articles including patients reporting on the incidence of failure (i.e. persistence of infection requiring reoperation) of the treatment of bacterial arthritis. The quality of individual evidence were assessed using the Quality in Prognosis Studies (QUIPS) tool. Failure rates were extracted from included studies and pooled. Risk factors for failure were extracted and grouped. Moreover, we evaluated which risk factors were significantly associated with failure. Results: Thirty studies (8,586 native joints) were included in the final analysis. The overall pooled failure rate was 26% (95% CI 20 to 32%). The failure rate of arthroscopy and arthrotomy was 26% (95% CI 19 to 34%) and 24% (95% CI 17 to 33%), respectively. Seventy-nine potential risk factors were extracted and grouped. Moderate evidence was found for one risk factor (synovial white blood cell count), and limited evidence was found for five risk factors (i.e. sepsis, large joint infection, the volume of irrigation, blood urea nitrogen-test, and blood urea nitrogen/creatinine ratio). Conclusion: A single surgical debridement fails to control bacterial arthritis of a native joint in approximately a quarter of all adult cases. Limited to moderate evidence exists that risk factors associated with failure are: synovial white blood cell count, sepsis, large joint infection, and the volume of irrigation. These factors should urge physicians to be especially receptive to signs of an adverse clinical course. [ABSTRACT FROM AUTHOR]

A novel optimization algorithm called musical chairs algorithm (MCA) is introduced in this paper for a shorter convergence time and lower failure rate compared to other optimization algorithms. This idea is implemented by using several search agents at the beginning of optimization steps and reduces this number gradually by removing the worst solutions. This idea is inspired by the musical chairs game in which the players and chairs are reduced by one in each round of the game. The proposed methodology has been compared with 10 other optimization algorithms for 10 benchmark functions. The results obtained from this comparison study showed superior performance of the MCA compared to the other optimization algorithms for all benchmark functions and different numbers of search agents. The convergence time varied between 3.8% and 18.2% compared to the average convergence time for all optimization algorithms applied with all benchmark functions. At the same time, the failure rate of the MCA is 0% for all the benchmark functions, but other optimization algorithms give a percentage of the failure rate. Moreover, the MCA is applied to feature selection of load forecasting as a real-world application which is vital for smart grid applications. The MCA is modified from continuous to binary MCA (BMCA). The BMCA is compared to several optimization algorithms, where it outperforms other optimization algorithms to select the best set of features to quickly and correctly learn the forecasting model. The accuracy of the obtained results from BMCA is increased to 96.7% compared to 70% of other algorithms, and the convergence time is reduced to 0.096 s compared to 18 s for other optimization algorithms. The outstanding results of MCA compared to the other optimization algorithms prove its superiority for all types of applications even with very complex benchmark functions. [ABSTRACT FROM AUTHOR]

Online optimization applications require fast convergence without sacrificing accuracy. Although the gray wolf optimization (GWO) algorithm is showing good convergence performance, it still needs further improvement to achieve these requirements. Optimal determination of the GWO control parameters can substantially improve the converge performance. All studies in the literature introduced efforts in tuning these parameters on try-and-error bases which may not satisfy the requirements of the online applications. For this reason, a novel nested improved GWO (NEST-IGWO) is used to determine the optimal control parameters for the IGWO. This novel strategy substantially improved the convergence time and accuracy, especially with online control systems. This strategy is having two nested IGWO loops. The internal IGWO loop includes the target function needed to be optimized. Meanwhile, the external loop is used to optimally determine the control parameters of the internal one. The objective function of the external loop is the failure rate and convergence time of the internal one. The results obtained from the NEST-IGWO are compared to 10 existing optimization algorithms for 10 different benchmark functions. Moreover, these optimization algorithms were applied to determine the parameters of the PV-cell model as a real-world application. The results showed that NEST-IGWO outperformed the other 10 optimization algorithms for all benchmark functions understudy and the estimations of the PV-cell parameters in terms of failure rate and convergence time. With the use of the NEST-IGWO, the convergence time is reduced by 90% of the average convergence time for all other algorithms. Moreover, the failure rate is reduced to 0% which is not the case for other algorithms understudy. These outstanding results prove the superiority of the NEST-IGWO compared to the other algorithms, and it opens a new venue for determining optimal control parameters for all optimization algorithms. [ABSTRACT FROM AUTHOR]

Any smart product needs to be advertised to generate more consumer demand and lower sale prices. Naturally, any smart product's demand rises when its price falls. This research proposes a multi-product production method that considers advertising and price-dependent stochastic demand for products and where the production system's failure rate is reduced while consuming the least amount of energy. This paper also investigates issues like unusual carbon emissions, energy consumption and machine breakdowns common in long-run production systems. To guarantee product quality, the current model adopts an inspection cost method. An autonomation policy is also discussed to have an error-free inspection. Hence, we construct a model where items that are not perfect are easily detected from the production process. This makes the production process smarter. The machine's production rate and failure rate determine the unit production cost. Further, the optimum energy costs of the model contain all expenditures associated with the manufacturing process. This study aims to identify the ideal combination of advertising expenses and selling price that will result in the highest possible profit with the fewest failed attempts. The model's total profit is a complex, non-linear function, which is solved numerically using an iterative process. Furthermore, the hessian matrix also provided for the optimality of the numerical validation. In order to determine the solution that works best for the developed model, the Mathematica software has been utilized. [ABSTRACT FROM AUTHOR]

Renewal-type and renewal equations usually do not have analytical solutions, and hence bounds for the functions satisfying such equations have a great practical importance. In this paper, sequences of monotone non-decreasing general lower bounds and sequences of monotone non-increasing general upper bounds for a general renewal-type equation converging to the function under interest, are given. Similar sequences of such two-sided bounds are given for the renewal function of an ordinary renewal process which converge to the renewal function and are improvements of the famous corresponding bounds of Marshall (1973). Also, such sequences of bounds converging to the ordinary renewal function, are obtained for several reliability classes of the lifetime distributions of the inter-arrival times. Finally, sequences of such two-sided bounds are given for the ordinary renewal density as well as for the right-tail of the distribution of the forward recurrence time (excess lifetime). [ABSTRACT FROM AUTHOR]

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The high level of reliability of water resources is always an advantage for consumers, but in arid and semi-arid regions where the inflow to the reservoir is faced with severe fluctuations, it makes sense to decrease the percentage of reliability of the system and allocate less water to consumption zones to prevent critical conditions such as emptying of the reservoir. In this research, the employed operation model is based on the simulation–optimization combination by considering the objectives of minimizing the violation of the allowed capacity of the reservoir and maximizing the percentage of supplying the demands. The optimal hedging variables are specified by linking the WEAP (Water Evaluation and Planning System) to the MOPSO multi-objective optimization algorithm. According to the available data, the duration of the simulation and optimization period in the model is 360 months. After 1000 iterations, the optimal reservoir volume values are obtained at the hedging level and hedging coefficient in different months. Finally, the model results are compared with the results obtained from the standard operation policy (SOP). The results show that the proposed model is able to manage the allocation to needs in the dry months and prevent the reservoir from emptying. Also, by storing a part of the flow in the reservoir in watery months and consuming it in low water months, it increases the supply of needs by 20 to 35% and reduces the failure rate in dry months. [ABSTRACT FROM AUTHOR]

This article deals with a cost minimization objective function of an economic production quantity (EPQ) inventory model with production breakdown and deterioration. The process reliability and the environmental pollution due to over production have also been considered. The model has been split into two different scenarios according to the breaking time before and after the production period. In scenario 1, no machinery failure occurs during production run time and that of scenario 2 the failure occurs during production run time. We develop a deterministic cost minimization problem first then we fuzzify the model by considering the production rate, the demand rate and all the cost components as lock fuzzy numbers. We convert the fuzzy model into equivalent game problem by considering Gaussian normal strategic probabilities. The model has been solved with the help of different key vectors employed by the decision maker. We have shown that the value of the game might be changed with the change of different key vectors. A comparative study has been made with the numerical results of the general fuzzy and crisp models. Finally, graphical illustrations and sensitivity analysis have been done followed by a conclusion. [ABSTRACT FROM AUTHOR]

A survey has revealed a relationship between the temperature factor and the biomechanical parameters (the modulus of elasticity) for wood tissues in the silver birch tree (Betula pendula Roth). At thawing temperatures, the elastic modulus decreases, on average, 2–2.5 times. A decrease of this kind is uneven, gradual. The rate of elastic-modulus change relative to the rate of woody-plant specimen/trunk thawing has the greatest effect on the mechanical stability of a tree. During thawing, the mechanical stability parameters tend to fall by 45%, on average. These changes affect the angles of divergence from the vertical axis of the trunk portions, the angles of its skeletal branch attachment, bending strength, and tree resistance to wind and gravity loads. Under a low anthropogenic impact, the bending stiffness value for plants at the age of 40–45 years is 22 ± 2% higher than that under the higher anthropogenic load in a city. Under the impact of anthropogenic load affected by the impact of wind loads, temperatures, and the other factors affecting weather, the transformation of architectonics of the silver birch crown occurs, which can cause irreversible deformations or trunk breakage under a blizzard and freezing rain. Therefore, 63 trees were uprooted and 168 woody plants underwent irreversible deformation, causing a high failure rate on the experimental plots in Donetsk from 2014 to 2020. Splits were recorded in plants at heights of 2–4 m (35%), 5–6 m (17%), 7–8 m (52%), and 9 m (6%). Correlation analysis revealed a strong positive relationship between the L : D morphometric coefficient (trunk length-to-diameter ratio) and the mechanical stability (R = 0.87), along with the failure rate (R = 0.79) of silver birch trees. In this regard, it seems possible to use the L : D coefficient as a morphometric marker for mechanical stability in silver birch trees in the south of the East European Plain (Donetsk Hill Ridge). [ABSTRACT FROM AUTHOR]

A method for calculating the reliability of locomotive safety devices is considered. The main types of calculations for rolling stock reliability indicators are described. Variants of test schemes for rolling stock units for the experimental determination of their reliability indicators are considered. A method is proposed for calculating the reliability indicators of locomotive safety devices, which makes it possible to predict the state of these units during the operation period. Structural diagrams of element redundancy systems are described. The indicators of reliability of locomotive safety devices are determined: the failure rate, the receiver reliability function, transmitter, and indicator. General redundancy is selected, i.e., a system with a permanently enabled reserve and an integer multiplicity. [ABSTRACT FROM AUTHOR]

Background: To investigate the long-term effect of hypertensive phase (HP) on the clinical outcomes of Ahmed glaucoma valve (AGV) implantation. Method: The records of patients with different etiologies of glaucoma who underwent AGV implantation with at least 3 years of follow-up were retrospectively reviewed. HP was defined as the IOP > 21 mm Hg during the first three months after surgery. The main outcome measure was cumulative success defined as 5 < IOP ≤ 21 mmHg and 20% reduction from the baseline with or without IOP lowering medications. Results that do not achieve cumulative success or undergo glaucoma reoperation during the follow-up period are considered failures. The secondary outcome measures were intraocular pressure (IOP) and the number of glaucoma medications. Results: A total of 120 patients (28 patients of HP, 92 patients without HP) with an average age (± SD) of 48.9 ± 19.6 years and a mean follow-up of 4.5 ± 1.4 years were enrolled. The mean duration of survival was 5.3 ± 0.5 years in HP which was significantly shorter than 6.4 ± 0.2 years in non-HP (log rank = 4.2, P = 0.04). Mean IOP and number of IOP lowering agents were higher in postoperative visits at 1,2, 3, and 4 years in HP patients compared with non-HP (all Ps < 0.01). Higher baseline IOP was significantly associated with higher rates of surgical failure. Conclusion: In the long-term follow-up, the duration of survival was significantly longer in the non-HP group. In the non-HP group, the failure rate was significantly lower than the HP group. [ABSTRACT FROM AUTHOR]

Abstract—Proposals have been developed and recommendations have been provided on the most probable rational use of technical domestic raw material upon its processing into marketable products with a high added value. For successful implementation of the proposed projects, it is important to correctly assess the opportunities of governmental support of the developed design engineering and procedural institutional measures on creation of commercially attractive industrial complexes for the recovery of pyrite cinders and copper smelting wastes. The industrial problems can be solved, since favorable conditions are available in Russia for constructive solution of the challenging problem of rational use of metal-containing technical raw materials. [ABSTRACT FROM AUTHOR]

The rational failure rate estimation has always been a great challenge in electric power distribution companies' regulatory. To prevent risk creation for companies and guarantee their encouragement to improve the distribution system's reliability, companies should calculate the failure rate by approximation and low error. Several factors influence the failure rate, including asset life, geographical factors, clash culture with installations, urban planning, etc. On the other hand, the history of investing in this system can also cause high exhaustion in assets. It is virtually impossible to consider all these factors and achieve a rational failure rate. Also, insufficient investment in the past years of electricity distribution companies is an important factor in asset aging and determining the failure rate. On the other hand, the company's investment trend is affected by the accepted failure rate of the regulator for each distribution company. In this paper, using the investment process and the total worth of assets of power distribution companies in each year, a model is presented to estimate the failure rate of the network. The failure rate calculated with this model can divide the budget between power distribution companies by the regulator and determine the rewards and penalties. [ABSTRACT FROM AUTHOR]

Let F, G be a pair of absolutely continuous cumulative distributions, where F is the distribution of interest and G is assumed to be known. The composition G - 1 ∘ F , which is referred to as the generalised hazard function of F with respect to G, provides a flexible framework for statistical inference of F under shape restrictions, determined by G, which enables the generalisation of some well-known models, such as the increasing hazard rate family. This paper is concerned with the problem of testing the null hypothesis H 0 : " G - 1 ∘ F is convex". The test statistic is based on the distance between the empirical distribution function and a corresponding isotonic estimator, which is denoted as the greatest relatively-convex minorant of the empirical distribution with respect to G. Under H 0 , this estimator converges uniformly to F, giving rise to a rather simple and general procedure for deriving families of consistent tests, without any support restriction. As an application, a goodness-of-fit test for the increasing hazard rate family is provided. [ABSTRACT FROM AUTHOR]

An increasing demand of wireless sensor network which have the capability to provide the good quality of service during real time application. Good QoS in WSN along with the real time application is a big challenge during given interval of time. Because with the real time application the WSN deals with the failure of the component, failure during sensing of data and its repairing capability under given interval of time duration. All these challenges affect the WSN quality of service in terms of reliability, availability and serviceability (RAS) parameters. In the proposed hybrid approach the design and implementation of WSN deals with hardware and software interface. This approach shows the enhancement of reliability, availability and serviceability during given interval of time. During the given interval of time the calculation of failure rate, MTBF, MTTR, MDT and repair rate is take place. These calculations represent the RAS capability of the WSN. WSN shows the withstand capability during the given condition with real time application. [ABSTRACT FROM AUTHOR]

Stochastic models for correlated count data have been attracting a lot of interest in the recent years, due to their many possible applications: for example, in quality control, marketing, insurance, health sciences, and so on. In this paper, we revise a bivariate geometric model, introduced by Roy (J Multivar Anal 46:362–373, 1993), which is very appealing, since it generalizes the univariate concept of constant failure rate—which characterizes the geometric distribution within the class of all discrete random variables—in two dimensions, by introducing the concept of "locally constant" bivariate failure rates. We mainly focus on four aspects of this model that have not been investigated so far: (1) pseudo-random simulation, (2) attainable Pearson's correlations, (3) stress–strength reliability parameter, and (4) parameter estimation. A Monte Carlo simulation study is carried out in order to assess the performance of the different estimators proposed and application to real data, along with a comparison with alternative bivariate discrete models, is provided as well. [ABSTRACT FROM AUTHOR]

The installation of vertical mobility systems (escalators) in high rise building has increased significantly in the recent past. Escalator systems which have been part of the utilities since the early 60s, has impact not only the movement of people and goods, but businesses that needs them to operate. It has lead to the need for continuous monitoring of the systems for failure by operators and reliability engineers. Although several authors have addressed failure related issue in the escalator system in past, literature has shown however, that the research works have not fully addressed issues relating to the root cause of failure in the system. In this paper, a reliability-centered model has been proposed and used for evaluating the root cause of failure issues in the escalator system by prioritizing the failure modes in the system. Results from the evaluation show that the failure mode 'Failure of the drag chain' has the highest risk and reliability concerns, while the 'Handrail fault' has the least risk and reliability concerns. To further check the feasibility and rationality of the model for addressing flexibility related issues that have become a basic characteristic of the modern fuzzy root cause of failure model, a sensitivity analysis has been performed using two quantitative reliability parameters of the escalator system that is 'the Mean Distance Between Failure and the Failure Rate'. [ABSTRACT FROM AUTHOR]

A sugar manufacturing plant is a complex industrial system having five subsystems arranged in a series configuration and each subsystem followed a different failure rate. Upon ensues of a random failure, the failed subsystem stops working and forces the complete system to stop and results in a downstate of the plant. The impact of downstate directly influences the production of plant and its reliability. Here, a reliability and maintainability analysis of the sugar manufacturing plant has been carried out at the subsystem and plant level. Data collection has been performed for six months from the sugar plant and descriptive statistical analysis has been made for time to repair and time between failures. The best-fitted distribution and parameters were determined along with trend and serial correlation analysis to attain the best performance of the plant. Additionally, graphs for reliability and hazard rate modes for five subsystems and the entire plant were depicted. The suggested models might be a suitable tool towards (a) considering the recent conditions, and (b) forecasting reliability for refining the sugar manufacturing plant by applying proper maintenance policy. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this systematic review was to compare the success rate of five tooth-coloured materials, namely Glass Ionomer (GI), Resin-Modified Glass Ionomer (RMGI), Composite Resin (CR), Polyacid-Modified Composite Resin or Compomer (CO) and High-Viscosity Glass Ionomer (HVGI) in primary molar Class II restorations. Methods: Five databases were searched from inception to April 23, 2020 for randomized clinical trials comparing the failure rate of these materials. After duplicate study removal, data extraction and risk of bias assessment with the Cochrane tool, data synthesis was conducted, comparing all five tooth-coloured materials in pairs and computing the overall success rate for each one, respectively. Results: A total of 5615 articles were obtained by electronic and hand literature search. After the application of the eligibility criteria, ten RCTs were included in this systematic review and six RCTs for meta-analysis. Their risk of bias was assessed to be high to moderate. Due to the small number of RCTs comparing the five restorative materials in pairs investigated in the same study, only three MAs were available for heterogeneity assessment. These were: (1) between CO-RMGI (RR 1.04 [0.59, 1.84]; p = 0.88; I2 = 1%), (2) CR-CO (RR 1.12 [0.41, 3.02]; p = 0.83; I2 = 57%), and (3) between CR-RMGI (RR 1.10 [0.74, 1.63]; p = 0.65; I2 = 0%). No statistically significant differences were found between the two materials in all three comparisons. Conclusion: CR, RMGI and CO presented no statistical differences. In comparison to other tooth-coloured materials, studies on GI were too few to allow recommendations about its use. More studies on HGVI are needed for evidence-based recommendations to be made. The evidence extracted from this meta-analysis was not strong enough (moderate), due to the small number of RCTs and the risk of bias ranging from high to moderate. More, well-designed RCTs comparing tooth-coloured materials for primary molar Class II restorations are necessary. [ABSTRACT FROM AUTHOR]

The best known result about the joint distribution of the backward and forward recurrence times in a renewal process concerns the asymptotic behavior for the tail of that bivariate distribution. In the present paper we study the joint behavior of the recurrence times at a fixed time point t, and we obtain both exact results and bounds for their joint tail behavior. We also obtain results about the joint moments of these two random variables and we show in particular that the expectation of the product between the two recurrence times increases with time when the interarrival distribution has a decreasing failure rate. The results are illustrated by some numerical examples. [ABSTRACT FROM AUTHOR]

Torus network topology offers many advantages such as higher speed, lower latency, better fairness, and lower energy consumption. For these kinds of benefits, nowadays, it is used to construct many parallel and distributed systems like IBM Blue Gene, IBM Sequoia, Mira, and Sugon TC8600. In parallel and distributed computing, multiple nodes act together to carry out large tasks fast. Hence, coordination is indispensable among these nodes to complete such tasks. A possible coordination method could be to elect a leader among the nodes. Along with coordination, the elected leader node also manages other activities such as task allocation, result aggregation, clock synchronization, proficient resource sharing management, and communication among the system's nodes. In this paper, we propose a lower bound Ω (N log 3 N) of message complexity on a comparison-based leader election for a 2D torus network (where N is the number of nodes in the network). Next, we sketch a new leader election algorithm (Lea-TN) considering both the node and link failures for a 2D torus network. This Lea-TN is a deterministic and robust algorithm that elects a leader for a synchronous distributed system. The algorithm chooses a leader, even when there are some link or node failures in the system. We consider the number of non-faulty links and the subsisting nodes' failure rate to elect a reliable leader. We introduce new patterns for sending messages that help reduce the number of exchanged messages and the execution time of the election process. The proposed algorithm (Lea-TN) enables a node to identify its link failures during the election also. Further, we simulate the Lea-TN algorithm and compare its performance with that of the well-known existing algorithms. [ABSTRACT FROM AUTHOR]

A new failure distribution for reliability evaluation of modern technological systems is proposed in this article. Methods for estimation the parameters of this distribution were presented based on failure statistics and the dependence of reliability indexes was investigated over time. The proposed failure distribution can be applied to describe the different failure behavior of modern machines and man-machine systems. On the example of practical cases, the hypothesis of compliance of the proposed theoretical law of distributions to the actual statistical data on failures of various technological systems was tested by the criterion χ2 - K. Pearson. [ABSTRACT FROM AUTHOR]

A method has been developed for calculating the standard indicators of the reliability of elements of restored gas analytical systems for monitoring chemical pollution of the environment according to experimental reference data which differ in the simultaneous use of different results of processing experimental information obtained by the standard method, the interval method, and the Kaplan–Meier method, making it possible to test the reliability of small (cost-effective) samples of products under the conditions of their possible elimination from observation for reasons not related to failure. This methodology makes it possible to reduce the cost of development work and reduce the degree of uncertainty in the development of a maintenance and repair strategy not only for the specialized gas analytical systems under consideration, but also to solve the problems of optimal control of the operational reliability of a wide class of refurbished complex chemical and technical systems at the design stage. [ABSTRACT FROM AUTHOR]

Fog computing broadens the computing services to serve requests of Internet of Things (IoT) by resources at the edge of Cloud-Fog environments instead of serving these requests by resources at the environment's core. The aim of fog computing is to reduce load of computing in data centers and reduce latency of requests, especially real-time ones. Load balancing and scheduling play essential roles and represent main key challenges to guarantee high throughput and reliability of services in Cloud-Fog environments. Therefore, this paper introduces a reliable scheduling approach for allocating customers' requests to the resources of Cloud-Fog environments. The approach is called Load Balanced Service Scheduling Approach (LBSSA) and it considers load balancing among resources when assigning requests to them by classifying requests to real-time, important and time-tolerant. In addition, scheduling of requests in the proposed approach considers the failure rate of resources in order to provide high reliability for requested services. The approach has a set of algorithms for handling different types of requests. Simulation experiments using CloudSim are conducted to assess the LBSSA approach in terms of number of computing resources, utilization of resources, load balance variance and running time. [ABSTRACT FROM AUTHOR]

The pipes as one of the main and important components of a water distribution network break during operation due to various factors. Developing models for pipes failure rate prediction can be one of the most important tools for managers and stakeholders during optimal operation of the water distribution network. In this study, the statistical and soft models such as Linear Regression, Generalized Linear Regression, Support Vector Machine, Feed Forward Neural Network (FFNN), Radial-Based Function Neural Network (RBFNN), and Adaptive Neuro-Fuzzy Inference System (ANFIS) were studied in order to predict the pipes failure rate based on the characteristics of Gorgan city water distribution network including diameter, length, age, installation depth, and number of failures of each pipe. In order to determine the optimal values of the parameters of each model, appropriate error indices including correlation coefficient (R), Mean Square Error (MSE), and Correlation Mean Square Error Ratio (CMSER) for training and test data were calculated, and the values of the parameters related to the model with the highest value of the CMSER index were considered as the model optimal values. Furthermore, in the validation stage, the values of R and MSE error indices for each of the above models were considered as a criterion for selecting the most appropriate model for predicting pipe failure rate. The findings show that among the soft and statistical models investigated, ANFIS with MSE of 0.071 and R of 0.92 can predict the failure rate of the studied network pipes more efficiently and more accurately than other models. Yet, despite the superiority of this model over other models, this model cannot accurately predict the failure rate of the studied network pipes due to its relatively high MSE value. Therefore, a new approach was developed based on the hybridization of trained models to provide a more efficient model for a more accurate prediction of the pipe failure rates of water distribution network. In this approach, the values of the network pipe failure rate predicted by each of the soft and statistical models are considered as independent input variables, and the observational failure rate values are considered as the dependent output variable of the ANFIS model. A comparison between the values of non-hybrid model validation data indices and the results of the proposed hybrid prediction model reveals that the use of the developed hybrid model increased the R error value from 8.1% (compared to the ANFIS model) to 260% (compared to the RBFNN model). It also decreased the MSE error value from 37% (compared to the FFNN model) to 58% (compared to the RBFNN model). Moreover, the hybrid model, compared to the superior non-hybrid ANFIS model, decreased MSE error rates by 45%. The findings show that the proposed model can significantly raise the accuracy of predicting the failure rate of pipes, compared to other existing models. [ABSTRACT FROM AUTHOR]

Purpose: To compare clinical and radiological outcomes and failure rates between anatomical and high femoral tunnels in remnant-preserving single-bundle posterior cruciate ligament (PCL) reconstruction. Methods: 63 patients who underwent remnant-preserving single-bundle PCL reconstruction between 2011 and 2018 with a minimum 2-year follow-up were retrospectively reviewed. Patients were divided into two groups according to the femoral tunnel position: group A (33 patients with anatomical femoral tunnel) and group H (30 patients with high femoral tunnels). The femoral tunnel was positioned at the center (group A) or upper margin (group H) of the remnant anterolateral bundle. The position of the femoral tunnel was evaluated using the grid method on three-dimensional computed tomography. Clinical and radiological outcomes and failure rates were compared between the groups at the 2-year follow-up. Results: The position of the femoral tunnel was significantly high in group H than in group A (87.4% ± 4.2% versus 76.1% ± 3.7%, p < 0.001). Clinical outcomes were not significantly different between the two groups in terms of the clinical scores (International Knee Documentation Committee subjective, Lysholm, and Tegner activity scores), range of motion, and posterior drawer test. Radiological outcomes also showed no intergroup differences in the side-to-side differences of posterior tibial translation and osteoarthritis progression. Side-to-side difference on the Telos stress radiograph was 5.2 ± 2.9 mm in group A and 5.2 ± 2.7 mm in group H (n.s.). There were four failures in group A (12.1%) and one in group H (3.3%). The differences between the groups were not statistically significant. Conclusion: The clinical and radiological outcomes and failure rates of the high femoral tunnels were comparable with those of the anatomical femoral tunnels at the 2-year follow-up after remnant-preserving single-bundle PCL reconstruction. The findings of this study suggest that high femoral tunnels can be considered an alternative in remnant-preserving single-bundle PCL reconstruction. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Recent works on seismic hazard have introduced the concept of time-dependent seismic hazard and different models have been proposed to predict the inter-arrival time between consecutive events. Currently, the reliability assessment of structures and relevant design rules proposed by the codes are based on the Poisson recursive model, for which the frequency of the occurrence of seismic events does not change over time. This paper presents results on the impact of Time-Dependent Seismic Hazard on structural design, by evaluating the strength required by the structure (seismic capacity) for different time intervals elapsing from the last event. "Seismic capacity" is understood here as the capacity required to provide a fixed reliability level, measured by the failure rate. Two different seismic scenarios have been investigated and results concerning different site-to-source distance, capacity dispersion of the structure and different recurrence properties of the time-dependent source have been discussed. Finally, the impact of recursive properties of time-dependent model is analysed and discussed. The results obtained from the analyses highlight a significant influence of time-dependent hazard properties on the structural capacity required to attain a target reliability, and give evidence to the different roles played by the parameters considered in the analysis. Within the set of the considered case studies, the ratios between seismic capacities evaluated by the time-dependent and non-time-dependent model span the range [0,1.32] in the first scenario, where inter-arrival time varies from 0 to two times the mean return period. The second scenario involves multiple sources and observed ratios were in the range [0.84,1.23], extreme values are relevant to inter-arrival times equal to 139 y and 371 y, respectively. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine the anterior cruciate ligament reconstruction (ACLR) failure rate in young patients utilizing the New Zealand (NZ) anterior cruciate ligament (ACL) Registry. The hypothesis was that the ACLR rupture rate would be lower for thicker hamstring graft and bone patellar tendon bone (BPB) grafts in comparison to the classic hamstring technique. The ACLR failure rate was assessed according to graft type and patients' sex. Methods: The NZ ACL registry was utilized to identify all patients aged 20 years or younger at the time of surgery who were skeletally mature and had a minimum 2-year follow-up. Graft ruptures, defined as an ACL revision, were identified according to graft type (traditional 4 strands hamstring semitendinosus and gracilis, 4 strands semitendinosus, 5–6 strands semitendinosus and gracilis, 7–8 strands semitendinosus and gracilis, bone-patella-bone graft). Results: Nine-hundred and ninety-two patients were included. At a mean follow-up of 38 months, 52 cases of graft rupture were recorded, (overall failure rate: 5.2%). The failure rate was not statistically influenced by the graft diameter. Patients with a thinner graft (< 8 mm—196 patients) had a similar failure rate (6%) to patients with a thicker graft (8 mm or more—485 patients) (6.2%). There was a lower failure rate in the BPB group (3.1%) versus all hamstrings group (6%) (ns). Finally, BPB in females had a lower failure rate than all hamstring constructs together (0% versus 5.1%; p = 0.023) Conclusion: In a young population traditional four-strand hamstring grafts, multiple strand configurations or BPB ACLR, whatever their size (> or < 8 mm), showed no significant difference in the failure rate in the NZ ACL registry. Female patients who had an ACL reconstruction with BPB graft had a significant lower failure rate than patients who had a hamstring graft. Level of evidence: III. [ABSTRACT FROM AUTHOR]

In a distributed system, multiple nodes work together to build a highly available, reliable, resource shareable, and fault-tolerant system to achieve a common goal. Here, multiple nodes work together to complete a task, so coordination is essential among these nodes. Electing a node as a system leader from among all the nodes can be a possible solution to do the coordination. Besides coordination, the leader also controls various activities like task allocation, result aggregation, efficient resource sharing, clock synchronization, and communication among the nodes of the system. In this work, we address the leader election problem through a new leader election algorithm called Failure Rate and Load-based Leader Election (FRLLE) algorithm for bidirectional ring networks. The proposed algorithm elects a node with a minimum failure rate and load as well so that the system gets a more reliable leader that can concentrate on leadership roles and activity comfortably. Like a proper leader election algorithm, this algorithm satisfies safety, liveness, and termination conditions that help to build an efficient and consistent distributed system. This algorithm reduces the message and time complexity, which means the algorithm takes fewer time steps to elect a leader by exchanging fewer messages. We compare the simulation results of the FRLLE algorithm with the well-known existing leader election algorithms and demonstrate that the FRLLE algorithm exchanges fewer messages and takes fewer time steps to elect the leader. We further carried out a priori complexity analysis and compared the outcome with the results of the simulation to corroborate our proposal. [ABSTRACT FROM AUTHOR]

This article is about reaching and securing high reliability and safety in engineering systems during the design and testing of developmental prototypes. A new approach to and technique of calculation of the design reliability is proposed, taking into account both kinds of failure rates, those that are constant and those that change over time. The function for calculation of design reliability is represented by the product of three constituents of failsafe operation probabilities throughout the whole period of operation, considering the calculation of the reliability of mechanical components and metalwork. The calculation model proposed for reaching and securing the required reliability and safety levels takes into account controlling actions. A new approach and technique, as well as mathematical models, for planning the scope of testing for various laws of run-to-failure distribution are proposed on the basis of nondiscardability of expensive objects. The study results are recommended for use in creating complex engineering systems. [ABSTRACT FROM AUTHOR]

A product typically exhibits three different failure rates across its lifetime: increasing, decreasing, or constant. This paper studies how the characteristics of failure rate impact the supply chain coordination for an extendedwarranty programinvolving a manufacturer and a retailer. Atwo-stage Stackelberg game is utilized to model the interaction between these two players. Two extended warranty channel structures are compared depending on whether the manufacturer or the retailer offers the warranty service. The analysis shows that the failure rate trend during the warranty period has different effects on the coordination of the service supply chain. When a product has an increasing or constant failure rate, the optimal length of extended warranty offered by the retailer is longer than that of the manufacturer, while the optimal length is shorter for a product with a decreasing failure rate. If a product during the warranty coverage has an increasing or constant failure rate, a longer extended warranty period will motivate customers to buy the product without the warranty, whereas more customers will buy both the product and the warranty if the product experiences a decreasing failure rate. It is concluded that, if the manufacturer and the retailer incur the same warranty service cost, the total profit in the supply chain is higher when the manufacturer offers the extended warranty. From the game participants' perspective, the one which sells the extended warranty will obtain more profit. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare patient demographics, associated lesions (concurrent meniscal and chondral injuries), and clinical outcomes between revision and re-revision anterior cruciate ligament reconstructions.Methods: Patients who underwent revision or re-revision anterior cruciate ligament reconstruction between 2008 and 2016 with a minimum 2-year follow-up were retrospectively evaluated. Detailed patient demographic data, radiographic preoperative tunnel diameters, posterior tibia slope, and concurrent meniscal and chondral lesion were reviewed. Clinical scores and laxity tests' results were compared between the groups at the last follow-up.Results: Eighty-two patients (mean age, 33.8 ± 9.9 years; revision group, n = 62; re-revision group, n = 20) were included. The re-revision group showed a higher grade for preoperative arthritis (P < 0.001); more severe preoperative bone defects of the femoral (13.8 ± 2.6 vs 11.7 ± 2.7 mm, P = 0.004) and tibial tunnels (14.6 ± 2.4 vs 13.0 ± 2.3 mm, P = 0.010); and a higher prevalence of subtotal medial meniscectomy (P = 0.008) and chondral defects of the medial (P = 0.006) and lateral femoral condyles (P < 0.001), patella (P = 0.040), and trochlea (P = 0.036). At the final follow-up, the clinical scores did not differ significantly between the groups. However, the re-revision group showed more instability in the anterior drawer (P = 0.001), Lachman (P < 0.001), and pivot-shift (P < 0.001) tests, while a side-to-side difference was observed on the Telos stress radiographs (7.1 ± 4.7 vs 4.9 ± 3.7 mm, P = 0.038).Conclusion: These findings showed that the patients who underwent re-revision had poor prognostic factors as compared with those who underwent revision anterior cruciate ligament reconstruction. Although the clinical scores did not differ significantly between the groups, the re-revision group showed more laxity at the 2-year follow-up.Level Of Evidence: Cohort study; IV. [ABSTRACT FROM AUTHOR]

The reliability of complex engineering objects is affected not only by the duration of the failure-free service (the continuous lifetime) but also the number of no-failure actuations to switch on the object into operation or switch it off (the discrete lifetime). The aim of this work is to fill this gap in part. [ABSTRACT FROM AUTHOR]

Abstract—One promising trend in making voltage converters more reliable is to design them on the basis of backbone modular architecture, combined redundancy, and rotation of main and backup power channels. A technique is proposed for this converter for calculating the upper and the lower failsafe operation probability estimates that is based on using the standardized model for the sliding loaded redundancy group. It is shown that the session rate of failures can be used as the channel fail-safety indicator in the rotation of channels. The proposed technique allows finding these estimates as time functions and considering the rate of channel failures not only in the converter's running mode, but in the standby mode as well. An example of calculating the converter's failsafe operation estimates is presented; a similar calculation by imitative modeling is provided to confirm the obtained results. It is shown that a shortened full channel rotation cycle makes the channels spend the resource in a more even manner, has no effect on the converter's fault-free performance figures at an absolutely reliable switch, and reduces them in the case of an unreliable switch. [ABSTRACT FROM AUTHOR]

Fog computing (FC) is an extension of cloud computing, however, it utilizes the resources close to the edge of the network. FC is a valuable choice to support real time applications such as healthcare, industrial systems, and intelligent traffic signs. However, Fog is a new emerging computing paradigm and still needs standardization in many issues especially in load balancing. This paper presents a new Effective Load Balancing Strategy (ELBS) for FC environment, which is suitable for Healthcare applications. ELBS tries to achieve effective load balancing in Fog environment via real-time scheduling as well as caching algorithms. It introduces several rules to accomplish reliable interconnections among fog servers. Moreover, the proposed ELBS guarantees a suitable interconnection among fog servers and both cloud and dew layer servers. ELBS is composed of five modules namely: (i) Priority Assigning Strategy (PAS), (ii) Data Searching Algorithm (DSA), (iii) External Data Requesting Algorithm (EDRA), (iv) Server Requesting Algorithm (SRA), and (v) Probabilistic Neural Network based Matchmaking Algorithm (PMA). PAS assigns a priority to each incoming Process (P) by considering three predefined parameters, which are; Predefined Priority (PP), Deadline Time (DT), and Task Size (TS). All those parameters are the inputs to a fuzzy inference system to assign the process priority. DSA is an algorithm to provide the required data for each arrived process in its fog region. EDRA is an algorithm used to search for the required data for each process in the neighbor servers. SRA is responsible for searching for the FS with the required capabilities for the incoming process. ELBS uses PMA to assign the process to the most appropriate server. It also defines a perfect methodology for a reliable connectivity among nodes. ELBS has been implemented and compared against recent load balancing techniques using iFogSim. Experimental results have shown that ELBS outperforms recent load balancing techniques as it achieves the lowest Average Turnaround Time and Failure Rate. Accordingly, ELBS is a suitable strategy to achieve load balancing in fog environment as it guarantees a reliable execution for real time applications. [ABSTRACT FROM AUTHOR]

For estimating the reliability of existing and newly developed circuit diagrams of heat networks, a special procedure is applied. By applying this procedure, which uses such input data as the length and operation time of pipeline segments, it is possible to determine the availability factors and probabilities of failure-free operation for a heat network. The aims of this study are to reveal and consider additional factors in determining the failure rate of heat network pipelines and to develop a new procedure for calculating indicators characterizing the reliability of heat supply to consumers. The failure rate of heat network elements depends, apart from the time they have been in operation, on the pipeline wall residual thickness, corrosion activity of soil, pipeline material, failure of a pipeline batch, other (previous) bursts in the considered segment, conduit flooding (flooding traces), and intersections with other utility lines. Additional factors significantly influencing the heat supply reliability, which, however, have not been included in the currently used procedure, are revealed, and an algorithm for calculating the heat network reliability is developed. The influence of the additional factors on the reliability of heat network operation is evaluated proceeding from the field data presented by regional heat supply companies. The influence of additional factors is taken into account in elaborating the new procedure and algorithm for calculating the heat supply's reliability indicators. The results from numerical and experimental investigations confirmed the possibility of using the obtained functional dependencies for elaborating a procedure of calculating heat network's reliability taking external factors into account. [ABSTRACT FROM AUTHOR]

Reliable networking is an important factor in Ethernet ring mesh networks (ERMs) with ITU-T G.8032 Ethernet ring protection recommendation or with the IEC 62439-3 high-availability seamless redundancy protocol. However, there are two major challenges for this purpose: (1) Hitherto, irregular topologies are used in ERMs that it causes difficulty in analyzing and improving reliability. (2) A topology is appropriate for practical implementation, if it is low cost, simple to implement, and simple to develop for large scale-systems (i.e. scalable). However, irregular topologies are extremely difficult to implement and develop. To deal with these challenges, this paper introduces two regular topologies called chordal ring and k-cube networks, for the first time in the area of ERMs. In addition, the proposed topologies are carefully analyzed in terms of reliability. These analyzes prove that the proposed regular topologies outperform existing irregular multiple-ring networks namely shared link, shared node, complex shared link, redundant link, and 3-connected network. [ABSTRACT FROM AUTHOR]

Bathtub failure rate shape is widely used in industrial and medical applications. In this paper, a three-parameter lifetime distribution, so-called the generalized Weibull uniform distribution that extends the Weibull distribution, is proposed and studied. This distribution has bathtub-shaped or decreasing failure rate function which enables it to fit real lifetime data sets. Various structural properties of the new distribution are derived, including explicit expressions for the quantile function, moments, moment-generating function and order statistics. Parameter estimations are provided by a maximum likelihood estimation, and the performance of the maximum likelihood estimation is evaluated using a simulation study. An application to real-life data demonstrates that the proposed distribution can be very useful in fitting real data. [ABSTRACT FROM AUTHOR]

The volume of data collected from cyber physical systems (CPS) is huge, and we use big data techniques to manage and store the data. Big data in CPS is concerned with the massive heterogeneous data streams, which are acquired from autonomous sources and computed in distributed data storage system. In order to handle the size, complexity and rate of availability of data, it requires new techniques that can inspect and interpret useful knowledge from large streams of information, which impose challenges on the design and management of CPS in multiple aspects such as performance, energy efficiency, security, privacy, reliability, sustainability, fault tolerance, scalability and flexibility. This paper focuses on the security and privacy aspects in managing big data for CPS and reviews recent challenges in data privacy. We also present a protection framework for intrusion detection and analyze the performance parameters, reliability and failure rate in a malicious big data context. [ABSTRACT FROM AUTHOR]

Traditionally, in applications, the shot noise processes have been studied under the assumption that the underlying arrival point process (shock process) is the homogeneous (or nonhomogeneous) Poisson process. However, most of the real life shock processes do not possess the independent increments property and the Poisson assumption is made just for simplicity. Recently, in the literature, a new point process, the generalized Polya process (GPP), has been proposed and characterized. The GPP is defined via the stochastic intensity that depends on the number of events in the previous interval and, therefore, does not possess the independent increments property. In this paper, we consider the GPP as an underlying shock process for the shot noise process. The corresponding survival model is considered and the survival probability and its failure rate are derived and thoroughly analyzed. Furthermore, a new concept, the history-dependent residual life time, is defined and discussed. [ABSTRACT FROM AUTHOR]