scholarly journals Reliability Simulation of Two Component Warm-Standby System with Repair, Switching, and Back-Switching Failures under Three Aging Assumptions

Mathematics ◽  
2021 ◽  
Vol 9 (20) ◽  
pp. 2547
Author(s):  
Kiril Tenekedjiev ◽  
Simon Cooley ◽  
Boyan Mednikarov ◽  
Guixin Fan ◽  
Natalia Nikolova
Keyword(s):  
Failure Rate ◽  
Primary Component ◽  
The Other ◽  
System Failures ◽  
First Case ◽  
Reliability Characteristics ◽  
Two Component ◽  
Standby System ◽  
Dependent Failure ◽  
Warm Standby

We analyze the influence of repair on a two-component warm-standby system with switching and back-switching failures. The repair of the primary component follows a minimal process, i.e., it experiences full aging during the repair. The backup component operates only while the primary component is being repaired, but it can also fail in standby, in which case there will be no repair for the backup component (as there is no indication of the failure). Four types of system failures are investigated: both components fail to operate in a different order or one of two types of switching failures occur. The reliability behavior of the system is investigated under three different aging assumptions for the backup component during warm-standby: full aging, no aging, and partial aging. Four failure and repair distributions determine the reliability behavior of the system. We analyzed two cases—in the First Case, we utilized constant failure rate distributions. In the Second Case, we applied the more realistic time-dependent failure rates. We used three methods to identify the reliability characteristics of the system: analytical, numerical, and simulational. The analytical approach is limited and only viable for constant failure rate distributions i.e., the First Case. The numerical method integrates simultaneous Algebraic Differential Equations. It produces a solution in the First Case under any type of aging, and in the Second Case but only under the assumption of full aging in warm-standby. On the other hand, the developed simulation algorithms produce solutions for any set of distributions (i.e., the First Case and the Second Case) under any of the three aging assumptions for the backup component in standby. The simulation solution is quantitively verified by comparison with the other two methods, and qualitatively verified by comparing the solutions under the three aging assumptions. It is numerically proven that the full aging and no aging solutions could serve as bounds of the partial aging case even when the precise mechanism of partial aging is unknown.

A Novel Strategy for Probability-Based Failure Avoidance of Operating Technical Systems

2001 ◽  
Author(s):  
Dirk Söffker
Keyword(s):  
Failure Rate ◽  
Operating Conditions ◽  
Fault Detection And Isolation ◽  
Reliability Engineering ◽  
Reliability Characteristics ◽  
Safety And Reliability ◽  
Reliability Control ◽  
Technical Systems ◽  
Novel Strategy ◽  
Dependent Failure

Abstract Failure and fault avoidance techniques are becoming important methodologies due to economical and ecological risks of modern technologies. The basic methodologies and techniques developing safe systems are connected with reliability engineering technologies or fault detection and isolation (FDI) approaches. The contribution introduces into the ideas of the 1997 firstly published SRCE (Safety and Reliability Control Engineering)-concept. Core of the approach is the development of a history- and load-dependent failure rate, which allows the online-calculation of reliability characteristics, which can be monitored or controlled. The classical definitions of reliability engineering characteristics are unfit due to the fact that they are only ‘driven’ by the time, so effects of changing operating conditions etc. can not be considered directly. The proposed approach solves this problem by introducing a new definition of a failure rate by introducing load- and lifetime-dependent failure rate. This also includes the possibility to consider regenerating/recovering effects of technical systems or components. As an example the determination is illustrated and applied to the monitoring of an automotive tire.

A NEW APPROACH TO THE STUDY OF COORDINATIVE CONSTRUCTIONS

2019 ◽  
pp. 175-187
Author(s):  
Anna Varnayeva
Keyword(s):  
Characteristic Property ◽  
Mathematical Concept ◽  
The Other ◽  
New Approach ◽  
Logical Aspect ◽  
First Case

Coordinative constructions are traditionally opposed to subordinative constructions. However, this opposition comes down to denial of dependence in coordinative constructions. Thereby the parity of these two constructions does not come to light: subordinative construction can be described without coordinative one. This situation is not improved by detection of a coordinative triangle in all coordinative constructions. The article shows a new approach in the study of coordinative constructions: a coordinative construction is a system; there are not only specific relations – a coordinative triangle, – but also specific elements. Novelty of the study consists in the address to extralinguistic facts, viz. a mathematical concept of a set and its elements. There are a lot of similarities between them. A set in mathematics includes generalizing elements and the composed row in coordinative constructions; in the first case the set is not partitioned, in the second case it is partitioned. In mathematics equivalent components in coordinative constructions correspond to the set elements. A characteristic property in mathematics is homogeneity in coordinative constructions and etc. It is firstly demonstrated, that coordinative and subordinative constructions are correlative and the study of one construction is impossible without the study of the other one. Their parity is shown in coordinative constructions with elements of one set, in subordinative ones with elements of different sets. Cf.: roses and tulips –red roses. In the coordinatiму construction elements of one set are called: «flowers »; in the subordinative construction there are elements of different sets: «flowers » and «colors». It should be noted that the mathematical concept of a set relates to so called logical aspect in linguistics or thinking about reality.

scholarly journals Long-Term Clinical Outcomes of Osteochondritis Dissecans Lesions of the Elbow Treated with Arthroscopy

2021 ◽  
Vol 9 (7_suppl4) ◽  
pp. 2325967121S0020
Author(s):  
Michael Ryan ◽  
Benton Emblom ◽  
E. Lyle Cain ◽  
Jeffrey Dugas ◽  
Marcus Rothermich
Keyword(s):  
Surgical Treatment ◽  
Clinical Outcomes ◽  
Failure Rate ◽  
Osteochondritis Dissecans ◽  
Surgical Techniques ◽  
The Other ◽  
Return To Play ◽  
Exclusion Criteria

Objectives: While numerous studies exist evaluating the short-term clinical outcomes for patients who underwent arthroscopy for osteochondritis dissecans (OCD) of the capitellum, literature on long-term clinical outcomes for a relatively high number of this subset of patients from a single institution is limited. We performed a retrospective analysis on all patients treated surgically for OCD of the capitellum at our institution from January 2001 to August 2018. Our hypothesis was that clinical outcomes for patients treated arthroscopically for OCD of the capitellum would be favorable, with improved subjective pain scores and acceptable return to play for these patients. Methods: Inclusion criteria for this study included the diagnosis and surgical treatment of OCD of the capitellum treated arthroscopically with greater than 2-year follow-up. Exclusion criteria included any surgical treatment on the ipsilateral elbow prior to the first elbow arthroscopy for OCD at our institution, a missing operative report, and/or any portions of the arthroscopic procedure that were done open. Follow-up was achieved over the phone by a single author using three questionnaires: American Shoulder and Elbow Surgeons – Elbow (ASES-E), Andrews/Carson KJOC, and our institution-specific return-to-play questionnaire. Results: After the inclusion and exclusion criteria were applied to our surgical database, our institution identified 101 patients eligible for this study. Of these patients, 3 were then excluded for incomplete operative reports, leaving 98 patients. Of those 98 patients, 81 were successfully contacted over the phone for an 82.7% follow-up rate. The average age for this group at arthroscopy was 15.2 years old and average post-operative time at follow-up was 8.2 years. Of the 81 patients, 74 had abrasion chondroplasty of the capitellar OCD lesion (91.4%) while the other 7 had minor debridement (8.6%). Of the 74 abrasion chondroplasties, 29 of those had microfracture, (39.2% of that subgroup and 35.8% of the entire inclusion group). Of the microfracture group, 4 also had an intraarticular, iliac crest, mesenchymal stem-cell injection into the elbow (13.7% of capitellar microfractures, 5.4% of abrasion chondroplasties, and 4.9% of the inclusion group overall). Additional arthroscopic procedures included osteophyte debridement, minor synovectomies, capsular releases, manipulation under anesthesia, and plica excisions. Nine patients had subsequent revision arthroscopy (11.1% failure rate, 5 of which were at our institution and 4 of which were elsewhere). There were also 3 patients within the inclusion group that had ulnar collateral ligament reconstruction/repair (3.7%, 1 of which was done at our institution and the other 2 elsewhere). Lastly, 3 patients had shoulder operations on the ipsilateral extremity (3.7%, 1 operation done at our institution and the other 2 elsewhere). To control for confounding variables, scores for the questionnaires were assessed only for patients with no other surgeries on the operative arm following arthroscopy (66 patients). This group had an adjusted average follow-up of 7.9 years. For the ASES-E questionnaire, the difference between the average of the ASES-E function scores for the right and the left was 0.87 out of a maximum of 36. ASES-E pain was an average of 2.37 out of a max pain scale of 50 and surgical satisfaction was an average of 9.5 out of 10. The average Andrews/Carson score out of a 100 was 91.5 and the average KJOC score was 90.5 out of 100. Additionally, out of the 64 patients evaluated who played sports at the time of their arthroscopy, 3 ceased athletic participation due to limitations of the elbow. Conclusions: In conclusion, this study demonstrated an excellent return-to-play rate and comparable subjective long-term questionnaire scores with a 11.1% failure rate following arthroscopy for OCD of the capitellum. Further statistical analysis is needed for additional comparisons, including return-to-play between different sports, outcome comparisons between different surgical techniques performed during the arthroscopies, and to what degree the size of the lesion, number of loose bodies removed or other associated comorbidities can influence long-term clinical outcomes.

scholarly journals Analysis of reliability of systems with component-wise storages

2018 ◽  
Vol 58 ◽  
pp. 02024 ◽  
Author(s):  
Yuriy E. Obzherin ◽  
Stanislav M Sidorov ◽  
Mikhail M Nikitin
Keyword(s):  
Phase Space ◽  
Energy Systems ◽  
Two Component System ◽  
Additional Time ◽  
Component System ◽  
Time Redundancy ◽  
Reliability Characteristics ◽  
Two Component ◽  
Semi Markov Processes ◽  
Time Reserve

Time redundancy is a method of increasing the reliability and efficiency of the operation of systems for various purposes, in particular, energy systems. A system with time redundancy is given additional time (a time reserve) for restoring characteristics. In this paper, based on the theory of semi-Markov processes with a common phase space of states, a semi-Markov model of a two-component system with a component-wise instantly replenished time reserve is constructed. The stationary reliability characteristics of the system under consideration are determined.

A Dynamic Interindustry Model for the Economic Analysis of Pollution Abatement

1974 ◽  
Vol 6 (3) ◽  
pp. 321-338 ◽  
Author(s):  
A Rose
Keyword(s):  
Linear Programming ◽  
Structural Changes ◽  
Environmental Control ◽  
Pollution Abatement ◽  
Primary Component ◽  
Component Model ◽  
Input Output ◽  
Two Component ◽  
Output System ◽  
Policy And Planning

A two-component model is presented for the analysis of the economic impact of pollution abatement. The primary component is a dynamic input-output system in which the structure of the economy is related to the level of environmental control as well as to time. A submodel, which consists of the various abatement activities within each industry, is used to explore the underlying nature of structural changes which take place as a result of changes in environmental regulations. The usefulness of the overall model for policy and planning purposes is illustrated by an example in which the submodel is transformed into a linear-programming format.

BRAIN TUMORS IN INFANCY

PEDIATRICS ◽  
1948 ◽  
Vol 1 (3) ◽  
pp. 346-363
Author(s):  
I. WALLACE LEIBNER
Keyword(s):  
Nervous System ◽  
Differential Diagnosis ◽  
Brain Tumors ◽  
Correct Diagnosis ◽  
Full Recovery ◽  
The Other ◽  
Congenital Hydrocephalus ◽  
First Case ◽  
Clinical Patterns

Seven cases of brain tumors occurring in infants are presented. Six occurred in males and one was in a female. Three of them arose in the cerebellum while the other four were supratentorial. The tumors included two medulloblastomas, one [See Table II in Source Pdf] spongioblastoma polare, one ependymoma, one astrocytoma and one hemangioblastoma. The seventh case probably was also one of medulloblastoma. One of the proven medulloblastomas was supratentorial, which is unusual so faras location is concerned. The hemangioblastoma arose in the cerebrum. The location of this tumor is also a rare one and to my knowledge, it is the first case of its type reported in an infant in whom full recovery occurred following removal of the tumor. The diagnosis was unsuspected in four cases. Three of these infants were believed to be suffering from congenital hydrocephalus while the fourth was thought to be afflicted with encephalitis. The ways in which the correct diagnosis might have been made are discussed. Since bizarre clinical patterns are sometimes produced by brain tumors in infants and the diagnosis frequently overlooked, the possibility should be kept in mind by the pediatrician in considering the differential diagnosis of conditions producing signs referable to the nervous system.

Significance of analysis of the mechanism of fingermarks formation, sizes and location – casework examples

2018 ◽  
Vol 301 ◽  
pp. 44-52
Author(s):  
Tomasz Kowalski ◽  
Keyword(s):  
Significant Role ◽  
Special Interest ◽  
The Other ◽  
Fatal Accident ◽  
Preliminary Stage ◽  
Additional Information ◽  
Expert Opinions ◽  
First Case ◽  
Initial Stage

The aim of the article to present the role of analysing the manner of generating fingermarks in the investigative proceedings. These examinations are based on the analysis of the location of the marks on a given background and aim at providing the requesting party additional information about the circumstances of the investigated incident. The Author refers to two unusual cases, in which Voivodeship Police Command Forensic Laboratory issued expert opinions in the area of fingerprint identification. In the first case, at the initial stage of the proceedings the circumstances and recovered evidential fingermarks indicated a fatal accident or manslaughter by means of a firearm. In the other case at the preliminary stage recovered evidence did not allow identification of the perpetrator due to incorrectly selected exhibits. These cases would not be off special interest to us without the significant role of proper recovering of fingermarks and their analysis in a broader context than just identification.

Pseudo-Restitutionary Damages: Some Thoughts on the Dual Theory of Restitution for Wrongs

2009 ◽  
Vol 22 (1) ◽  
pp. 49-78 ◽  
Author(s):  
Francesco Giglio
Keyword(s):  
The Other ◽  
Corrective Justice ◽  
Dual Theory ◽  
Judicial Decision ◽  
Legal Response ◽  
First Case ◽  
The Law ◽  
Compensatory Damages ◽  
Single Response

Restitution for civil wrongs, also known as restitutionary damages, is a legal response through which the defendant’s wrongful gain is awarded to the claimant. James Edelman has recently advocated two different restitutionary responses for wrongs. One response, termed ‘restitutionary damages’, would aim to compel the wrongdoer to give back to the victim a wrongful gain, whereas the other response, ‘disgorgement damages’, would oblige the wrongdoer to give up a wrongful gain for the benefit of the claimant.In the first case, the claimant would obtain what should have never left his assets. In the second case, the claimant would be the beneficiary of a judicial decision according to which a wrongful gain should not be kept by the wrongdoer. In this essay, I seek to demonstrate that this taxonomy cannot be accepted. I argue that Edelman’s ‘disgorgement damages’ are the only true example of restitution for wrongs, whereas his ’restitutionary damages’ are simply compensatory damages which are quantified in a particular fashion. Edelman’s ‘restitutionary damages’ might appear to deprive the defendant of his gain, and thus to achieve a restitutionary goal. Yet they nullify the victim’s loss and therefore have a compensatory nature. They are ‘pseudo-restitutionary damages’. In opposition to the dual theory, I submit a model of restitutionary damages based upon a single response which is coherent with the tenets of corrective justice. Given that it deals mainly with Edelman’s ‘restitutionary damages’, this article is not so much about restitution for wrongs but rather about compensation, which is what Edelman’s ‘restitutionary damages’ really concerns. The theory which I propose, based upon a single restitutionary response for wrongs, solves the taxonomic incoherence of Edelman’s dual theory. It also reflects the law as we find it, being supportable by reference to the available judicial authorities.

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