Impact of Hardware/Software Faults on System Reliability. Volume 1. Study Results.

1985 ◽  
Author(s):  
Edward C. Soistman ◽  
Katherine B. Ragsdale
Keyword(s):  
System Reliability ◽  
Software Faults ◽  
Study Results

A Software Reliability Model for Cloud-Based Software Rejuvenation Using Dynamic Fault Trees

2015 ◽  
Vol 25 (09n10) ◽  
pp. 1491-1513 ◽  
Author(s):  
Jean Rahme ◽  
Haiping Xu
Keyword(s):  
System Reliability ◽  
System Performance ◽  
High Reliability ◽  
Cost Effective ◽  
Reliability Function ◽  
Cloud Services ◽  
Software Faults ◽  
Software Aging ◽  
Software Rejuvenation ◽  
Dynamic Fault Tree

Correctly measuring the reliability and availability of a cloud-based system is critical for evaluating its system performance. Due to the promised high reliability of physical facilities provided for cloud services, software faults have become one of the major factors for the failures of cloud-based systems. In this paper, we focus on the software aging phenomenon where system performance may be progressively degraded due to exhaustion of system resources, fragmentation and accumulation of errors. We use a proactive technique, called software rejuvenation, to counteract the software aging problem. The dynamic fault tree (DFT) formalism is adopted to model the system reliability before and during a software rejuvenation process in an aging cloud-based system. A novel analytical approach is presented to derive the reliability function of a cloud-based Hot SPare (HSP) gate, which is further verified using Continuous Time Markov Chains (CTMC) for its correctness. We use a case study of a cloud-based system to illustrate the validity of our approach. Based on the reliability analytical results, we show how cost-effective software rejuvenation schedules can be created to keep the system reliability consistently staying above a predefined critical level.

scholarly journals System Availability Study Results in the Example of Radio Communication System in the Underground Mine

2021 ◽  
Author(s):  
Batzorig Bazargur ◽  
Otgonbayar Bataa ◽  
Uuganbayar Budjav
Keyword(s):  
Communication System ◽  
System Reliability ◽  
Underground Mine ◽  
Radio Communication ◽  
System Availability ◽  
Engineering Theory ◽  
Study Results ◽  
Parallel Connections ◽  
Radio Communication System ◽  
Resource System

The availability rating of any system is the probability that it will be able to operate for a given time in other words, to restore the system in the case of a system failure, or during the failure it is a measure of the availability index of resource system. We aimed to complete the study for the reasons as below. The rating and upgrading of underground mine radio communication system availability is to ensure operation reliability of the underground mine and to establish reliable radio communication system for miner’s safety during failure. Therefore, our study is contributed to reveal system availability rating of single resource (with two parallel connections) system and two resources (with three parallel connections) system. The study is related to not only practical contribution but also reliability engineering theory. To achieve this result, we have used Exponential, Weibull, and Poisson distributions. The readiness rating of single resource (with two parallel connections) and two resources (with three parallel connections) systems were calculated using Matlab software and the simulation results were introduced. This result confirms that any system has a resource system, which increases its readiness rating. The study was in examples of single resource radio communication system on the two shafts of the underground mine and two resource radio communication system for three shafts. During the initial system reliability enhancement study, the readiness of the dual resource system was assessed. The rating shows a 99 percent result, which is very meaningless for systems with more than two n-resources and we have revealed that it can show more than 100 percent result. In the process of the study on system reliability improvement the rating availability of system which has two resources was 99 % result. It is very meaningless for systems with more than two n-resources or more than 100% result.

Apportionment of Impairment from Meniscal Tears and Knee Arthritis

2013 ◽  
Vol 18 (5) ◽  
pp. 1-10 ◽  
Author(s):  
Charles N. Brooks ◽  
James B. Talmage
Keyword(s):  
Medial Meniscus ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Detailed Knowledge ◽  
Meniscal Tears ◽  
Knee Arthritis ◽  
Degenerative Arthritis ◽  
Study Results ◽  
Physical Findings ◽  
Causation Analysis

Abstract Meniscal tears and osteoarthritis (osteoarthrosis, degenerative arthritis, or degenerative joint disease) are two of the most common conditions involving the knee. This article includes definitions of apportionment and causes; presents a case report of initial and recurrent tears of the medial meniscus plus osteoarthritis (OA) in the medial compartment of the knee; and addresses questions regarding apportionment. The authors, experienced impairment raters who are knowledgeable regarding the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), show that, when instructions on impairment rating are incomplete, unclear, or inconsistent, interrater reliability diminishes (different physicians may derive different impairment estimates). Accurate apportionment of impairment is a demanding task that requires detailed knowledge of causation for the conditions in question; the mechanisms of injury or extent of exposures; prior and current symptoms, functional status, physical findings, and clinical study results; and use of the appropriate edition of the AMA Guides. Sometimes the available data are incomplete, requiring the rating physician to make assumptions. However, if those assumptions are reasonable and consistent with the medical literature and facts of the case, if the causation analysis is plausible, and if the examiner follows impairment rating instructions in the AMA Guides (or at least uses a rational and hence defensible method when instructions are suboptimal), the resulting apportionment should be credible.

Planned Home Births Safe, Study Results Suggest

Ob Gyn News ◽  
2005 ◽  
Vol 40 (14) ◽  
pp. 11
Author(s):  
MICHELE G. SULLIVAN
Keyword(s):  
Home Births ◽  
Study Results

Study Results Link Obesity and Asthma Severity

2007 ◽  
Vol 41 (4) ◽  
pp. 44
Author(s):  
DOUG BRUNK
Keyword(s):  
Asthma Severity ◽  
Study Results

Efficacy of compression stockings in preventing post-thrombotic syndrome in patients with deep venous thrombosis: a systematic review and metaanalysis

VASA ◽  
2016 ◽  
Vol 45 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Jakob Martin Burgstaller ◽  
Johann Steurer ◽  
Ulrike Held ◽  
Beatrice Amann-Vesti
Keyword(s):  
Systematic Review ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Cochrane Library ◽  
Compression Stockings ◽  
Post Thrombotic Syndrome ◽  
Study Results ◽  
Preventive Efficacy ◽  
One Year ◽  
The Cochrane Library

Abstract. Background: Here, we update an earlier systematic review on the preventive efficacy of active compression stockings in patients with diagnosed proximal deep venous thrombosis (DVT) by including the results of recently published trials. The aims are to synthesize the results of the original studies, and to identify details to explain heterogeneous results. Methods: We searched the Cochrane Library, PubMed, Scopus, and Medline for original studies that compared the preventive efficacy of active compression stockings with placebo or no compression stockings in patients with diagnosed proximal DVT. Only randomized controlled trials (RCTs) were included. Results: Five eligible RCTs with a total of 1393 patients (sample sizes ranged from 47 to 803 patients) were included. In three RCTs, patients started to wear compression stockings, placebo stockings or no stockings within the first three weeks after the diagnosis of DVT. The results of two RCTs indicate a statistically significant reduction in post-thrombotic syndrome (PTS) of 50% or more after two or more years. The result of one RCT shows no preventive effect of compression stockings at all. Due to the heterogeneity of the study results, we refrained from pooling the results of the RCTs. In a further RCT, randomization to groups with and without compression stockings took place six months after the diagnosis of DVT, and in another RCT, only patients with the absence of PTS one year after the diagnosis of DVT were analyzed. One RCT revealed a significant reduction in symptoms, whereas another RCT failed to show any benefit of using compression stockings. Conclusions: At this time, it does not seem to be justifiable to entirely abandon the recommendations regarding compression stockings to prevent PTS in patients with DVT. There is evidence favoring compression stockings, but there is also evidence showing no benefit of compression stockings.

Central Nervous System Processing of Emotions in Children with Fecal Incontinence and Constipation

2019 ◽  
Vol 47 (1) ◽  
pp. 67-71
Author(s):  
Monika Equit ◽  
Justine Niemczyk ◽  
Anna Kluth ◽  
Carla Thomas ◽  
Mathias Rubly ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Fecal Incontinence ◽  
Event Related Potentials ◽  
Anterior Cingulate ◽  
Afferent Pathways ◽  
Study Results ◽  
Related Potentials ◽  
The Central Nervous System ◽  
Cortical Regions

Abstract. Objective: Fecal incontinence and constipation are common disorders in childhood. The enteric nervous system and the central nervous system are highly interactive along the brain-gut axis. The interaction is mainly afferent. These afferent pathways include centers that are involved in the central nervous processing of emotions as the mid/posterior insula and the anterior cingulate cortex. A previous study revealed altered processing of emotions in children with fecal incontinence. The present study replicates these results. Methods: In order to analyze the processing of emotions, we compared the event-related potentials of 25 children with fecal incontinence and constipation to those of 15 control children during the presentation of positive, negative, and neutral pictures. Results: Children with fecal incontinence and constipation showed altered processing of emotions, especially in the parietal and central cortical regions. Conclusions: The main study results of the previous study were replicated, increasing the certainty and validity of the findings.

Delay Discounting in Impulsive Behavior

2019 ◽  
Vol 24 (4) ◽  
pp. 312-321 ◽  
Author(s):  
Diana Moreira ◽  
Fernando Barbosa
Keyword(s):  
Delay Discounting ◽  
Human Subjects ◽  
Empirical Studies ◽  
Cochrane Collaboration ◽  
Initial Assessment ◽  
Impulsive Behavior ◽  
Manual Search ◽  
Study Results ◽  
Depth Analysis ◽  
The Future

Abstract. Delay discounting (DD) is the process of devaluing results that happen in the future. With this review, we intend to identify specificities in the processes of DD in impulsive behavior. Studies were retrieved from multiple literature databases, through rigorous criteria (we included systematic reviews and empirical studies with adult human subjects), following the procedures of the Cochrane Collaboration initiative. Of the 174 documents obtained, 19 were considered eligible for inclusion and were retained for in-depth analysis. In addition, 13 studies from the manual search were included. Thus, a total of 32 studies were selected for review. The objectives/hypotheses, results, and the main conclusion(s) were extracted from each study. Results show that people with pronounced traits of impulsivity discount rewards more markedly, that is, they prefer immediate rewards, though of less value, or postponed losses, even though they worsen in the future. Taken together, the existing data suggest the importance of inserting DD as a tool for initial assessment in conjunction with measures of addiction and stress level, as well as the consideration of new therapies.

Investigating Personality and Psychopathology in Patients With Psoriasis

2017 ◽  
Vol 38 (2) ◽  
pp. 87-107 ◽  
Author(s):  
Chiara Vari ◽  
Patrizia Velotti ◽  
Alessandro Crisi ◽  
Silvana Carlesimo ◽  
Antonio G. Richetta ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Clinical Importance ◽  
Self Report ◽  
Psychological Issues ◽  
Self Evaluation ◽  
Affective Quality ◽  
Millon Clinical Multiaxial Inventory ◽  
Study Results ◽  
Completion Test ◽  
Skin Conditions

Abstract. A broad range of literature reported higher rates of psychopathology and personality disorders among patients affected by skin conditions. Specifically, depression, anxiety, and suicidal ideations are more frequently reported by patients affected by skin diseases. This study aimed to examine psychopathology and personality in a group of patients affected by psoriasis by means of a self-report measure (Millon Clinical Multiaxial Inventory – MCMI-III) and a performance-based technique (Wartegg Drawing Completion Test [WDCT], CWS). Study results showed a higher rate of passive-aggressiveness and paranoia among psoriatic patients (MCMI-III). When assessing patients through the performance-based technique (WDCT, CWS), a higher rate of global rejection (GR) – linked by previous literature to suicidal ideation – and a lower affective quality of the drawings emerged. We discuss the clinical importance of detecting psychological issues in dermatology patients by means of a multimethod assessment that goes beyond patients’ self-evaluation of their symptoms and emotions.

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