Increasing Failure Rate Research Articles

An SEU fault injection platform for radiation-harden design debugging in the FPGA

An SEU fault injection platform was designed to ease the debugging of radiation-harden design in FPGA. The platform includes the FPGA being tested, the functional firmware being debugged, the essential-bit extraction algorithm based on Python, and the random fault injection algorithm. The platform can inject single-bit SEU failures, adjacent two-bit SEU failures, and three-bit SEU failures. It works in two modes: normal injection mode and essential-bit injection mode. Functional failure rate is the performance metric which used to evaluate the development. It is the probability of triggering a DUT function failure. In this experiment, the SEU fault injection platform is verified by measuring whether TCP/IP communication links are disconnected due to SEU faults. Experimental results show that the probability of TCP/IP link disconnection in normal injection mode is 0.13%, 0.23% and 0.25% respectively when random injection of single-bit SEU failure, adjacent two-bit SEU failure and multi-bit SEU failure occurs 10,000 times. In the essential-bit injection mode, the probability of TCP/IP link disconnection caused by single-bit SEUs failure, adjacent two-bit SEUs failure and three-bit SEUs failure is 0.87%, 6.97% and 11.76% respectively, indicating a significant increase in the functional failure rates. This shows that the essential-bit injection mode can be used to expose problems more quickly and accelerate the debugging process of FPGA radiation-harden design.

Record-based transmuted generalized linear exponential distribution with increasing, decreasing and bathtub shaped failure rates

The linear exponential distribution is a generalization of the exponential and Rayleigh distributions. This distribution is one of the best models to fit data with increasing failure rate (IFR). But it does not provide a reasonable fit for modeling data with decreasing failure rate (DFR) and bathtub shaped failure rate (BTFR). To overcome this drawback, we propose a new record-based transmuted generalized linear exponential (RTGLE) distribution by using the technique of Balakrishnan and He. The family of RTGLE distributions is more flexible to fit the data sets with IFR, DFR, and BTFR, and also generalizes several well-known models as well as some new record-based transmuted models. This paper aims to study the statistical properties of RTGLE distribution, like, the shape of the probability density function and hazard function, quantile function and its applications, moments and its generating function, order and record statistics, Rényi entropy. The maximum likelihood estimators, least squares and weighted least squares estimators, Anderson-Darling estimators, Cramér-von Mises estimators of the unknown parameters are constructed and their biases and mean squared errors are reported via Monte Carlo simulation study. Finally, the real data sets illustrate the goodness of fit and applicability of the proposed distribution; hence, suitable recommendations are forwarded.

철도차량의 좌우측절단자료를 이용한 2단계 상태기반 점검주기 연구

Purpose: This paper introduces two-phase condition-based maintenance by analyzing left-truncated and right-censored field data, with characteristics managed by the existing maintenance schedule.BRMethods: The failure rate was initially observed as a constant failure rate (CFR) and, after a certain point, as an increasing failure rate (IFR). Therefore, a two-phase condition-based maintenance policy with each stage maintenance cycle was proposed. In addition, a maintenance model was developed to determine the optimal maintenance schedule in terms of economic feasibility.BRResults: The optimal maintenance schedule was derived by minimizing the total cost, including the inspection cost, failure cost, and improvement factor. Further, changes in the optimal maintenance schedule were examined based on the ratios of the inspection cost, failure cost, and improvement factor.BRConclusion: Designing a maintenance policy to evaluate the system conditions and mutual adequacy between the cost and improvement effect in terms of light and medium maintenance is essential.

Analyse biomécanique des plaques verrouillées pour la fixation des fractures diaphysaire des métacarpiens : étude analytique

BackgroundThere appears to be a paucity of knowledge about the biomechanics of locking plates for the fixation of metacarpal shaft fractures. A thorough understanding of the biomechanics of locking plates is needed to apply them correctly, optimize outcomes, and avoid complications. The purpose of this study is to investigate the biomechanics of the fixation of metacarpal fractures using locking plate-screw constructs with different numbers of screws. HypothesisThe difference in the number of screws in the locking plate influenced the biomechanical outcome of the metacarpal fracture. MethodsFinite element models of third metacarpal fractures with locking plate-screw constructs were established, and the magnitude and distribution of their stresses and displacements were investigated when a vertical load of 100N was applied. ResultsFor the metacarpal fracture with a locking plate and screws, the stress in the metacarpal was largely shared by the plate-screw construct. For the plate-screw construct, the stress is concentrated in the area close to the fracture line, and the 6-screw group has the lowest failure risk since it has the lowest plate stress and the second-lowest screw stress. The implant-bone construct with 8 screws has better biomechanical stability because of minimal displacement, but increased stress on both the metacarpal bone and the screws, leading to increased failure rates. DiscussionThe stresses in the metacarpal were mostly shared by the plate-screw constructs and the screws closest to the fracture line were the most likely to break or loosen. For the implant-bone constructs, the locking plate with 2 screws was the most vulnerable to break or loosen, whereas the locking plate with 6 screws was the least likely to break or loosen. The implant-bone construct with 8 screws had better biomechanical stability, but the stresses in both the metacarpal and the screws were increased, which increased the risk of failure. Level of evidenceIV, basic science study.

Common Challenges in Institutions of Education and Higher Education in Iraq Analytical- Social Study

Today the world goes through many challenges and difficulties which can only be addressed by science and knowledge, so the educational institution- which consists of a group of stages beginning with the pre-school stage through the primary and secondary stages and ending with the university stage represented by higher education institutions- shares the providing of the individual with knowledge which enables him/her address the requirements of life and this process entails a number of elements such as the existence of a student, a schoolteacher, a teacher, a professor and a scientific material whether theoretical or practical. The scientific institution, with its two types: the educational and the higher education, may face common challenges whether social, economic, political and cultural. Hence our research emerges trying to shed light on these challenges to find solutions for them via recommendations which the researchers have come up with in this research. in this research, the two researchers have adopted the analytical descriptive approach to achieve the goals of the research which has come up with a number of results the most prominent of which are the insufficient scientific buildings, the limited proficiency of the teaching staff together with the increase in failure rates among students in the education sector and the higher education in addition to that the curricula are old and do not fit the scientific and technological advances in schools and universities namely in the humanitarian studies.

991-P: Metformin Plasma Concentration as a Biomarker of Treatment Responsiveness in Youth-Onset Type 2 Diabetes

Metformin is the first-line therapy for youth-onset type 2 diabetes mellitus (Y-T2D) but is suboptimal in up to 50% of youth. The reasons for increased failure rates are unknown. Metformin plasma concentration reflects total body distribution and kinetics but is not used clinically in adults because peak metformin concentration varies widely. Few studies, and none in youth, have measured trough therapeutic concentration as a potential biomarker of response. We hypothesized that trough metformin plasma concentrations after short-term therapy would be associated with treatment response. In this secondary analysis of a randomized trial of metformin alone vs. metformin and liraglutide (combo) therapy Y-T2D youth, we determined the relationship of metformin concentration with glycemia. Nineteen Y-T2D: age 15.4±2.1 (12-20y) mean±SD (range) , 61% female, Tanner Stage IV-V, BMI 40.0±8.0 (22.1-53.4 kg/m2) were randomized to 2000mg/day metformin (n=10) or 2000mg metformin+ 1.8mg liraglutide (combo, n=8) for 3 months after a 5-7 day drug-free run-in period. At baseline, youth on combo had higher HbA1c (7.1±0.7; 6.2±0.6%, P=0.006) but had similar BMI, fasting glucose, and 2hr glucose on OGTT. Metformin concentrations increased (combo:337±559 vs. metformin: 420±433 (1.6-1537 ng/mL) , P=0.7) and negatively correlated with change in 2hr glucose (combo: r=-0.9, P=0.002; metformin: r=-0.73, P=0.02) , fasting glucose (combo: r=-0.59, P=0.13; metformin: r=-0.64, P=0.06) , and change in HbA1c (combo: r=-0.89, P=0.01, metformin: r=0.31, P=0.4) . Metformin adherence measured by pill counts was 78% with no difference by group (combo: 80±20; metformin: 75±16%) . Metformin concentrations were not associated with percent adherence to medication or change in weight (P>0.10) . Overall, metformin concentrations were widely variable in Y-T2D but associated with improvements in glycemia after 3 months and should be explored as a viable biomarker for predicting treatment response in Y-T2D. Disclosure K.B. Dietsche: None. A. Zenno: None. S.A. Dixon: None. L. Mabundo: None. E.L. Shouppe: None. D.E. Estrada: None. F.R. Cogen: None. M. Walter: None. P. Walter: None. S.T. Chung: None. Funding NIDDK/NIH Intramural Research Program

Gate Bias Effects on SiC MOSFET Terrestrial-Neutron Single-Event Burnout

Power devices are susceptible to failure by terrestrial neutron single-event burnout (SEB) while in the high-voltage blocking state and above a VDS threshold for that device. Typically, the SEB failure rate is measured at a high blocking voltage, with the source and gate at ground potential. Here the effect of a negative gate bias, commonly applied during MOSFET switching to the blocking state, on the SEB failure rate is examined. It is observed that the SEB failure rate is only weakly dependent on the negative gate bias, because it does not significantly affect the peak field in the drift region where avalanche breakdown is initiated. A negative gate bias of -8VGS in the device blocking state at 1100VDS only results in a 6% increase in the MOSFET SEB failure rate.

Biomechanical analysis of locking plates for fixation of metacarpal shaft fractures: A finite element analysis

BackgroundThere appears to be a paucity of knowledge about the biomechanics of locking plates for the fixation of metacarpal shaft fractures. A thorough understanding of the biomechanics of locking plates is needed to apply them correctly, optimize outcomes, and avoid complications. The purpose of this study is to investigate the biomechanics of the fixation of metacarpal fractures using locking plate-screw constructs with different numbers of screws. HypothesisThe difference in the number of screws in the locking plate influenced the biomechanical outcome of the metacarpal fracture. MethodsFinite element models of third metacarpal fractures with locking plate-screw constructs were established, and the magnitude and distribution of their stresses and displacements were investigated when a vertical load of 100N was applied. ResultsFor the metacarpal fracture with a locking plate and screws, the stress in the metacarpal was largely shared by the plate-screw construct. For the plate-screw construct, the stress is concentrated in the area close to the fracture line, and the 6-screw Group has the lowest failure risk since it has the lowest plate stress and the second-lowest screw stress. The implant-bone construct with 8 screws has better biomechanical stability because of minimal displacement, but increased stress on both the metacarpal bone and the screws, leading to increased failure rates. DiscussionThe stresses in the metacarpal were mostly shared by the plate-screw constructs and the screws closest to the fracture line were the most likely to break or loosen. For the implant-bone constructs, the locking plate with 2 screws was the most vulnerable to break or loosen, whereas the locking plate with 6 screws was the least likely to break or loosen. The implant-bone construct with 8 screws had better biomechanical stability, but the stresses in both the metacarpal and the screws were increased, which increased the risk of failure. Level of evidenceIV, basic science study.

T Stage and Pretreatment Standardized Uptake Values Predict Tumor Recurrence With 5-Fraction SABR in Early-Stage Non-Small Cell Lung Cancer

PurposeFive-fraction stereotactic ablative radiotherapy (SABR) regimens are frequently used to treat centrally located early-stage non-small cell lung cancer or disease in the proximity of the chest wall as a means of optimizing tumor control and reducing treatment toxicity. However, increasing these SABR regimens to 5 fractions may reduce tumor control outcomes. We sought to identify the clinical parameters predictive of treatment failures with these 5-fraction courses. MethodsNinety patients with T1-2 non-small cell lung cancer were treated with 50 or 60 Gy in 5 fractions. Failure over time was modeled using cumulative incidences of local, regional, or distant failure, with death as a competing risk. Cox proportional hazards analysis for incidences of failure was performed to control for patient variables. ResultsOf 90 patients, 24 of 53 patients with T1 tumors and 19 of 37 patients with T2 tumors received 50 Gy SABR, and the other 47 patients received 60 Gy. Two-year overall survival and progression-free survival for the whole cohort were 75.8% and 59.3%, respectively. Total SABR dose (50 vs 60 Gy) did not influence survival nor failure rates at 2 and 5 years. Within 2 years of treatment, 7.8% of all patients developed local failure. For all patient and tumor characteristics evaluated, only T stage and pretreatment positron emission tomography standardized uptake values served as predictors of local, regional, and distant failure at 2 and 5 years posttreatment on univariate and multivariable analysis. ConclusionsFive-fraction SABR provides excellent in-field control. T2 and high fluorodeoxyglucose uptake tumors have increased failure rates, suggesting the potential need for adjuvant therapies, which are being assessed in randomized phase 3 trials.

Mechanistic Insights for Drug Repurposing and the Design of Hybrid Drugs for Alzheimer's Disease.

The heterogeneity and complex nature of Alzheimer's disease (AD) is attributed to several genetic risk factors and molecular culprits. The slow pace and increasing failure rate of conventional drug discovery has led to the exploration of complementary strategies based on repurposing approved drugs to treat AD. Drug repurposing (DR) is a cost-effective, low-risk, and efficient approach for identifying novel therapeutic candidates for AD treatment. Similarly, hybrid drug design through the integration of distinct pharmacophores from known or failed drugs and natural products is an interesting strategy to target the multifactorial nature of AD. In this Perspective, we discuss the potential of DR and highlight promising drug candidates that can be advanced for clinical trials, backed by a detailed discussion on their plausible mechanisms of action. Our article fosters research on the hidden potential of DR and hybrid drug design with the goal of unravelling new drugs and targets to tackle AD.

Toward Smart Communication Components: Recent Advances in Human and AI Speaker Interaction

This study aims to investigate how humans and artificial intelligence (AI) speakers interact and to examine the interactions based on three types of communication failures: system, semantic, and effectiveness. We divided service failures using AI speaker user data provided by the top telecommunication service providers in South Korea and investigated the means to increase the continuity of product use for each type. We proved the occurrence of failure due to system error (H1) and negative results on sustainable use of the AI speaker due to not understanding the meaning (H2). It was observed that the number of users increases as the effectiveness failure rate increases. For single-person households constituted by persons in their 30s and 70s or older, the continued use of AI speakers was significant. We found that it alleviated loneliness and that human-machine interaction using AI speaker could reach a high level through a high degree of meaning transfer. We also expect AI speakers to play a positive role in single-person households, especially in cases of the elderly, which has become a tough challenge in the recent times.

A general multivariate lifetime model with a multivariate additive process as conditional hazard rate increment process

The object of the present paper is the study of the joint lifetime of d components subject to a common stressful external environment. Out of the stressing environment, the components are independent and the lifetime of each component is characterized by its failure (hazard) rate function. The impact of the external environment is modelled through an increase in the individual failure rates of the components. The failure rate increments due to the environment increase over time and they are dependent among components. The evolution of the joint failure rate increments is modelled by a non negative multivariate additive process, which include Lévy processes and non-homogeneous compound Poisson processes, hence encompassing several models from the previous literature. A full form expression is provided for the multivariate survival function with respect to the intensity measure of a general additive process, using the construction of an additive process from a Poisson random measure (or Poisson point process). The results are next specialized to Lévy processes and other additive processes (time-scaled Lévy processes, extended Lévy processes and shock models), thus providing simple and easily computable expressions. All results are provided under the assumption that the additive process has bounded variations, but it is possible to relax this assumption by means of approximation procedures, as is shown for the last model of this paper.

Inspecting Briquette Machine with Different Faults

Background: A briquette machine can be considered very useful in modern times as the need for energy consumption is increasing rapidly. Considering the harm to the environment, the study of the briquette machine is the need of present times. In this paper, the operative unit is considered as briquette machine, also known as bio-coal, which is used for agroforestry waste. Objective: A single operative unit has been analyzed stochastically. The inspection of the breakdown of a unit reveals the feasibility of the unit under the supervision of either ordinary or expert repairmen. Two types of faults are revealed by the repairmen, either minor or major. Minor faults are repaired immediately by the same repairmen, but whenever a major fault is held, the machine’s fault will be handled by an expert person. Method: It is assumed that the repair needs no modification once served. Availability, Mean-time for system failure, and profits are analyzed by utilizing the Regenerative point graphical technique and Semi-markov process. Result: The study reveals that the mean-time for system failure of the system model goes on decreasing as the failure rate increases and the availability goes on decreasing as failure-rate increases. Moreover, the study shows that the systems' profit goes down on an increase in Failure-rate. Conclusion: Findings of the study support the hypothesis that the limits of failure/repair/inspection rate will surely have effective profitability. Moreover, it is found that the utility of the scale of operation can easily be derived. The practical importance of biomass briquettes for burning coal or wood is very well appreciated.

A new alternative unit- Lindley distribution with increasing failure rate

In this paper, a new one-parameter distribution is proposed by unitizing the Lindley distribution through the hyperbolic tangent transformation. The goal is to map the functionality of the Lindley distribution on the unit interval, with the perspective of offering a new modeling option for treating unit data. In the first part, we provide the motivations and some mathematical properties of the new distribution. Two truncated moments and hazard rate functions are used to characterize the distribution. The emphasis is then switched to its statistical characteristics. Several methods are used to discuss the point estimation of the parameter. The related bias and mean squared error behavior is tested using Monte Carlo simulations for a range of sample sizes. To demonstrate the ability of the model to fit real data, distributional analyses are given.

Prior distributions expressing ignorance about convex increasing failure rates

AbstractThis paper deals with the specification of probability distributions expressing ignorance concerning annual or otherwise discretized failure or mortality rates, when these rates can safely be assumed to be increasing and convex, but are completely unknown otherwise. Such distributions can be used as noninformative priors for Bayesian analysis of failure data. We demonstrate why a uniform distribution used in earlier work is unsatisfactory, especially from the point of view of insensitivity with respect to the time scale that is chosen for the problem at hand. We suggest alternative distributions based on Dirichlet distributed weights for the extreme points of relevant convex sets, and discuss which consequences a requirement for scale neutrality has for the choice of Dirichlet parameters.

Efficient Reputation-based Cyber Attack Detection Mechanism for Big Data Environment

Objective: To reduce the cyber-attacks in IoT devices and also to provide security and reliable communication among the IoT devices and Edge servers, we have designed an Efficient Reputation-based Cyber-Attack Detection (ERCAD) mechanism for the Bigdata environment. Methods: This work presents an Efficient Reputation-based Cyber-Attack Detection (ERCAD) mechanism using the trust-based method. This work provides reliability and security by employing a trust-based security model and a feedback-based model. Moreover, to increase the network performance of the model which the existing system lacks, our model provides a reputation metric that classifies the malicious IoT nodes. Also, our model provides an efficient reputation cyber-attack detection communication metric for Bigdata Environment. Findings: Most of the Existing Reputation-Based Security (ERS)(1),(2),(3) models have achieved a good detection rate but have an increased failure rate. Furthermore, the ERS models have more throughput with more energy consumption and are less reliable and have not provided any QoS requirement and proper security for their models. Hence, the ERCAD model achieves a very good attack detection rate of 22.04% with a minimum detection failure rate of 33.89% for a wide range of attacks in comparison with Existing Reputation-Based Security (ERS) models. Moreover, the ERCAD improves throughput by 22.40% and with a reduction of energy consumption of 40.032% in comparison with Existing Reputation-Based Security (ERS) models and also is highly reliable by assuring QoS and security together. Novelty: The ERS models have failed to attain a better attack detection rate when the device is in the dynamic behavior. Further, are not efficient in modeling feedback reliability. Hence, our ERCAD model provides a better attack detection rate when the device is in dynamic behavior and also provides a security framework for classifying the malicious IoT nodes. Keywords: Reliability; Security; Detection; BigData Environment; QoS requirement

Sequential common change detection, isolation, and estimation in multiple poisson processes

In this article, motivated by detecting the occurrence of an epidemic when the arrival rates of patients increase in a portion of M panels or detecting the deterioration of a system composed of M independent components that causes an increase in failure rates in a portion of components, we consider the detection of a common change when M independent Poisson processes are monitored simultaneously where only a portion of the processes have rate increases after the change time. M individual cumulative sum (CUSUM) processes and Shiryaev-Roberts (S-R) processes are calculated recursively in parallel at each pooled arrival time. A systematic procedure is proposed by using the sum of M S-R processes as the detection process for a common change. After the detection, the M individual CUSUM processes are used to isolate the changed panels with false discovery rate (FDR) control and then the medians of the change time estimates from each individual CUSUM process or S-R process based on the isolated panels are used to estimate the common change time. The model can be generalized to different prechange rates, jittered change time, and unknown postchange rates.

Predicting Mechanical Failure Following Cervical Deformity Surgery: A Composite Score Integrating Age-Adjusted Cervical Alignment Targets.

Retrospective cohort study. Investigate a composite score to evaluate the relationship between alignment proportionality and risk of distal junctional kyphosis (DJK). 84 patients with minimum 1year follow-up were included (age = 61.1 ± 10.3years, 64.3% women). The Cervical Score was constructed using offsets from age-adjusted normative values for sagittal vertical axis (SVA), T1 Slope (TS), and TS minus cervical lordosis (CL). Individual points were assigned based on offset with age-adjusted alignment targets and summed to generate the Cervical Score. Rates of mechanical failure (DJK revision or severe DJK [DJK> 20° and ΔDJK> 10°]) were assessed overall and based on Cervical Score. Logistical regressions assessed associations between early radiographic alignment and 1-year failure rate. Mechanical failure rate was 21.4% (N = 18), 10.7% requiring revision. By multivariate logistical regression: 3-month T1S (OR: .935), TS-CL (OR:0.882), and SVA (OR:1.015) were independent predictors of 1-year failure (all P < .05). Cervical Score ranged (-6 to 6), 37.8% of patients between -1 and 1, and 50.0% with 2 or higher. DJK patients had significantly higher Cervical Score (4.1 ± 1.3 vs .6 ± 2.2, P < .001). Patients with a score ≥3 were significantly more likely to develop a failure (71.4%) with OR of 38.55 (95%CI [7.73; 192.26]) and Nagelkerke r2 .524 (P < .001). This study developed a composite alignment score predictive of mechanical failures in CD surgery. A score ≥3 at 3months following surgery was associated with a marked increase in failure rate. The Cervical Score can be used to analyze sagittal alignment and help define realignment objectives to reduce mechanical failure.

Economic Criteria for Optimizing the Assigned Service Life of Machinery and Equipment

The machine is used in a continuous production process in the enterprise that is a market participant. During its use, it can be subject to random failure after which losses occur due to interruption of the process. After failure, the machine is decommissioned and disposed of. Over time, the failure rate increases. Under these conditions, it turns out to be beneficial for the enterprise to set an assigned service life for the machine, after which (if no failure has occurred) it must be disposed of. We solve the problem of optimizing the assigned service life. Usually, to solve this problem, various optimality criteria are used, for example, average costs per unit of time (including the time to eliminate the consequences of a failure), reliability indicators, or other indicators that do not fully reflect the commercial interests of the enterprise owning the machine. Using the principles and methods of asset valuation, we build a mathematical model that allows us to calculate the optimal assigned life of the machine and at the same time assess the market value of the work performed by it. At the same time, in this problem, the optimality criterion is the ratio of the expected discounted costs to the expected discounted volume of work performed by the machine (in units of operating time). Using this criterion, the market value of the enterprise owning the machine will be the highest. The proposed model allows us to estimate the market value of the serviceable machine knowing its age. We compare the proposed and alternative optimality criteria. We give an example in which machine failures have a Rayleigh distribution. The proposed general approach can be used both in solving other optimization problems of reliability theory and for practical valuation of some types of machinery and equipment.

Optimization of Preventive Maintenance and Replacement Strategies for Nonrenewing Two-Dimensional Warranty Products Experiencing Degradation and External Shocks

“Vehicle damage insurance” in China, “Protection Plus Mobile Elite” launched by Samsung, “iPhone Apple Care +” offered by Apple, and so on are special warranty services aiming at external shocks. These warranty terms, named accident insurance, exist widely in the marketplace. Considering the effect of external shocks on degradation, a two-dimensional preventive maintenance and replacement strategy for products, sold with a nonrenewing and two-dimensional rectangle warranty service, is proposed in this paper. Under this strategy, preventive maintenance actions are scheduled based on units of age or usage, which occurs first. There is a reduction in the intensity function after a preventive maintenance action. Each shock before the Nth shock causes a failure of the product or an increase in product failure rate. The product is replaced by a new one on the Nth shock if it survives the N − 1 shocks. From the view of manufacturers, the mean warranty servicing cost over the whole warranty region is obtained by using the renewal theory. Based on direct numerical Riemann–Stieltjes integration, an approximation algorithm of the cost is also given. The mean cost is minimized by the optimization of preventive maintenance interval and the number of shocks N. A numerical example is given to illustrate the feasibility of the proposed strategy. The effects of maintenance cost, the arrival rate of the shocks, and other model parameters on the optimal strategy are also investigated numerically.