PROBABILITY MODELS FOR SEQUENTIAL-STAGE SYSTEM RELIABILITY GROWTH VIA FAILURE MODE REMOVAL

Author(s):  
DONALD P. GAVER ◽  
PATRICIA A. JACOBS ◽  
KEVIN D. GLAZEBROOK ◽  
ERNEST A. SEGLIE

This paper provides guidance for the planners of a test of any system that operates in sequential stages: only if the first stage functions properly (e.g., a vehicle's starter motor rotates adequately) can the second stage be activated (ignition system performs) and hence tested, followed by a third stage (engine starts and propels vehicle), with further stages such as wheels, and steering, and finally brakes eventually brought to test. Each sequential stage may fail to operate because its design, manufacture, or usage has faults or defects that may give rise to failure. Testing of all stages in the entire system in appropriate environments allows failures at the various stages to reveal defects, which are targets for removal. Early stages' fault activations thus postpone exposure of later stages to test. It is clear that only by allowing the entire system to be tested end-to-end, through all stages, and to observe several total system successes can one be assured that the integrated system is relatively free of defects and is likely to perform well if fielded. The methodology of the paper permits a test planner to hypothesize the numbers of (design) faults present in each stage, and the stagewise probability of a fault activation, leading to a system failure at that stage, given survival to that stage. If the test item fails at some stage, then rectification ("fix") of the design occurs, and the fault is (likely) removed. Failure at that stage is hence less likely on future tests, allowing later stages to be activated, tested, and fixed. So reliability grows. To allow many Test and Fix (TAF) cycles is obviously impractical. A stopping criterion proposed by E. A. Seglie that suggests test stopping as soon as an uninterrupted run/sequence of r (e.g., 5) consecutive system successes has been achieved is studied quantitatively here. It is shown how to calculate the probability of eventual field success if the design is frozen and the system fielded after such a sequential stopping criterion is achieved. The mean test length is also calculated. Many other calculations are possible, based on formulas presented.

Author(s):  
Bakhytzhan Zhumagulov ◽  
Alibek Issakhov ◽  
Askar Khikmetov

AbstractThis paper considers the unstable stratified turbulent flow in an open channel. A mathematical model of unstable stratified turbulent flow is introduced, which allows to assess the mean and fluctuation characteristics of the turbulent flow. The numerical algorithm is developed for solving this problem. A numerical method is based on the projection method, which divides the problem into three stages. At the first stage, it is assumed that the transfer of momentum occurs only by convection and diffusion. Intermediate velocity field is solved by fractional steps method. At the second stage, three-dimensional Poisson equation is solved by the Fourier method in combination with tridiagonal matrix method (Thomas algorithm). Finally, at the third stage, it is expected that the transfer is only due to the pressure gradient. The simulation results are in satisfactory agreement with the experimental data.


2015 ◽  
Vol 5 (3) ◽  
pp. 185-200
Author(s):  
Robert Z. Birdwell

Critics have argued that Elizabeth Gaskell's first novel, Mary Barton (1848), is split by a conflict between the modes of realism and romance. But the conflict does not render the novel incoherent, because Gaskell surpasses both modes through a utopian narrative that breaks with the conflict of form and gives coherence to the whole novel. Gaskell not only depicts what Thomas Carlyle called the ‘Condition of England’ in her work but also develops, through three stages, the utopia that will redeem this condition. The first stage is romantic nostalgia, a backward glance at Eden from the countryside surrounding Manchester. The second stage occurs in Manchester, as Gaskell mixes romance with a realistic mode, tracing a utopian drive toward death. The third stage is the utopian break with romantic and realistic accounts of the Condition of England and with the inadequate preceding conceptions of utopia. This third stage transforms narrative modes and figures a new mode of production.


2019 ◽  
Author(s):  
Lucy Armstrong ◽  
Lorna Hogg ◽  
Pamela Charlotte Jacobsen

The first stage of this project aims to identify assessment measures which include items on voice-hearing by way of a systematic review. The second stage is the development of a brief framework of categories of positive experiences of voice hearing, using a triangulated approach, drawing on views from both professionals and people with lived experience. The third stage will involve using the framework to identify any positve aspects of voice-hearing included in the voice hearing assessments identified in stage 1.


2021 ◽  
pp. 1-24
Author(s):  
Philipp Klar ◽  
Georg Northoff

The existential crisis of nihilism in schizophrenia has been reported since the early days of psychiatry. Taking first-person accounts concerning nihilistic experiences of both the self and the world as vantage point, we aim to develop a dynamic existential model of the pathological development of existential nihilism. Since the phenomenology of such a crisis is intrinsically subjective, we especially take the immediate and pre-reflective first-person perspective’s (FPP) experience (instead of objectified symptoms and diagnoses) of schizophrenia into consideration. The hereby developed existential model consists of 3 conceptualized stages that are nested into each other, which defines what we mean by existential. At the same time, the model intrinsically converges with the phenomenological concept of the self-world structure notable inside our existential framework. Regarding the 3 individual stages, we suggest that the onset or first stage of nihilistic pathogenesis is reflected by phenomenological solipsism, that is, a general disruption of the FPP experience. Paradigmatically, this initial disruption contains the well-known crisis of common sense in schizophrenia. The following second stage of epistemological solipsism negatively affects all possible perspectives of experience, that is, the first-, second-, and third-person perspectives of subjectivity. Therefore, within the second stage, solipsism expands from a disruption of immediate and pre-reflective experience (first stage) to a disruption of reflective experience and principal knowledge (second stage), as mirrored in abnormal epistemological limitations of principal knowledge. Finally, the experience of the annihilation of healthy self-consciousness into the ultimate collapse of the individual’s existence defines the third stage. The schizophrenic individual consequently loses her/his vital experience since the intentional structure of consciousness including any sense of reality breaks down. Such a descriptive-interpretative existential model of nihilism in schizophrenia may ultimately serve as input for future psychopathological investigations of nihilism in general, including, for instance, its manifestation in depression.


2021 ◽  
pp. 232102222110243
Author(s):  
Mohuya Deb Purkayastha ◽  
Joyeeta Deb ◽  
Ram Pratap Sinha

The present study estimated labour-use efficiency of 48 branches of Assam Gramin Vikash Bank at its branch level, covering three districts of Barak Valley, which falls under Silchar region of the bank for the time period from 2010–2011 to 2017–2018. The study applied data envelopment analysis for estimating labour-use efficiency. In the second stage, the study applied censored Tobit regression for determining the impact of several contextual variables on efficiency. The study reveals that the mean labour-use efficiency score of the selected branches is 76% when averaged for the in-sample branches over the observation period. Results of the Tobit regression identified cluster 2 and total business of the branches as the significant factors for determining efficiency and the number of employees as a significant variable influencing inefficiency. JEL Classifications: G2, G20, G21, J3


2002 ◽  
Vol 67 (3) ◽  
pp. 417-433 ◽  
Author(s):  
Kent V. Flannery

In Mesoamerica and the Near East, the emergence of the village seems to have involved two stages. In the first stage, individuals were distributed through a series of small circular-to-oval structures, accompanied by communal or “shared” storage features. In the second stage, nuclear families occupied substantial rectangular houses with private storage rooms. Over the last 30 years a wealth of data from the Near East, Egypt, the Trans-Caucasus, India, Africa, and the Southwest U.S. have enriched our understanding of this phenomenon. And in Mesoamerica and the Near East, evidence suggests that nuclear family households eventually gave way to a third stage, one featuring extended family households whose greater labor force made possible extensive multifaceted economies.


2018 ◽  
Vol 34 (02) ◽  
pp. 227-229
Author(s):  
Yi-gao Hu ◽  
Wei Ding ◽  
Jun Tan ◽  
Xin Chen ◽  
Tao Luo ◽  
...  

AbstractThis article investigates an effective method with which to reconstruct the tragus and external auditory meatus for microtia reconstruction. The external ear was reconstructed using a delayed postauricular skin flap in patients with congenital microtia. After the first stage of delaying the postauricular skin flap and the second stage of otoplasty with ear framework fabricated from autogenous rib cartilage draping with the delayed skin flap, the third stage involved tragus and external auditory meatus canaloplasty. After designing the remnant auricle flap, the lower part was trimmed and the tragus was reconstructed. The upper part was trimmed into a thin skin flap, which was rotated and used to cover the hollowed wound posterosuperior to the tragus so as to mimic the external auditory meatus. If remnant wounds were present, skin grafting was conducted. In total, 121 patients with congenital microtia were treated from March 2010 to March 2016. The reconstructed tragus and external auditory meatus were well formed, and all wounds healed well. No severe complications such as flap necrosis occurred. Six months postoperatively, the morphology of the reconstructed tragus and external auditory meatus was good. Overall, the patients and their families were satisfied. The use of remnant auricle to reconstruct the tragus and external auditory meatus is an effective auricular reconstruction technique.


The evolution of stored energy during heating for specimens of deformed α-brass is quite different from that previously observed for pure metals; the stored energy is much larger and at least three stages of evolution exist. These have been studied for deformation in torsion and tension and the results correlated with measurements of electrical resistivity, density and hardness. The large release of energy in the first two stages is attributed mainly to the return of order destroyed by plastic deformation; the degree of disorder after heavy cold work is much greater than after quenching (part II). However, slight deformation (10% tension) increases the degree of order slightly. The first stage of energy release, below 120 °C, is probably due to rapid reordering assisted by vacancies created during deformation. The second stage represents the bulk of the reordering and some recovery involving rearrangement and annihilation of dislocations. The deformed specimens are probably strain-aged and thus recovery is accompanied by the dispersal of atmospheres of zinc which increases resistivity and decreases density, to some extent counteracting the effects of recovery. The balance of these three processes in stage 2 causes complex behaviour, the magnitude and even the sign of some changes in properties varies with the deformation. Reordering is complete before the beginning of the third stage of further recovery and recrystallization, in which dispersal of atmospheres is again important. Comparison of measurements of energy, resistivity and density suggests that the high concentration of stacking faults contributes to the resistivity. Anneal hardening is observed for the higher deformations and the maximum hardness coincides with the maximum degree of order.


Author(s):  
Т.А. Богумил

В статье предлагается концепция жизни и творческого роста В.М. Шукшина сквозь призму тезаурусного и кластерного подходов. Объяснительными «персональными моделями» для интерпретации биографического текста писателя являются кластеры Мартина Идена, Гамлета и Степана Разина. Ранее биографы и литературоведы указывали на важность этих персон для Шукшина, но разрозненно. Впервые предпринята попытка свести указанные персональные модели воедино, в целостный сюжет становления писателя в пространстве культуры. На разных этапах эволюции автора доминирует одна из указанных моделей, последовательно сменяя друг друга, но не вытесняя, а «внахлест». Ранний этап творчества, ориентированный на стратегию Мартина Идена, является попыткой «вписаться» в наличный культурный мейнстрим. Выражено это в следовании поэтике соцреализма. Второй этап подспудно начинается с реабилитации отца Шукшина в 1956 года, когда актуализируется «гамлетовский комплекс», проявляющийся в чувстве вины перед отцом, через стратегию утаивания подлинного «я», мотивы чудаковатости. Третий этап связан с личностью реального исторического лица, Степана Разина, и выражается в открытом протесте против власти. Все важные для В.М. Шукшина поведенческие модели объединены мотивом одинокого противостояния враждебному социуму и имеют трагический финал, что обусловило ранний уход писателя и порождение мифов о насильственном характере его смерти. В.М. Шукшин одновременно был фигурой неординарной и типичной, что позволило его биографии стать «персональной моделью» для последующих авторов, выходцев из сельской глубинки. The article proposes the concept of life and creative growth of V.M. Shukshin through the prism of the thesaurus and cluster approach. The explanatory "personal models" for interpreting the biographical text of the writer are clusters of Martin Eden, Hamlet and Stepan Razin. Earlier, biographers and literary critics pointed out the importance of these people for Shukshin, but it was scattered. For the first time, an attempt was made to bring these personal models together into an integral plot of the formation of the writer in the space of culture. At different stages of the writer’s evolution, one of these models dominates, successively replacing each other, but not crowding out, but “overlapping”. The early stage of creativity, focused on Martin Eden’s strategy, is an attempt to “fit in” the current cultural mainstream. This is expressed in following the poetics of socialist realism. The second stage implicitly begins with the rehabilitation of Shukshin’s father in 1956, when the “Hamletian complex” is actualized. It is manifested in a sense of guilt towards his father, the strategy of concealing the true “I”, eccentricities. The third stage is connected with the personality of a real historical person, Stepan Razin, and is expressed in an open protest against the authorities. All important for V.M. Shukshin's behavioral models are united by the motive of a lonely confrontation with a hostile society and have a tragic ending, which led to the early departure of the writer and the generation of myths about the violent nature of his death. V.M. Shukshin was an extraordinary and typical figure at the same time. That allowed his biography to become a “personal model” for subsequent authors who came from the rural outback.


2020 ◽  
pp. 39-42
Author(s):  
D. V. Minukhin ◽  
O. I. Tsyvenko ◽  
A. Yu. Korolevska ◽  
L. G. Tarasenko ◽  
D. Yu. Melnyk ◽  
...  

Most authors considered pleural cavity drainage to be the main method of treatment of acute pleural empyema using minor surgery. Despite the simplicity of drainage of the pleural cavity, the number of complications after this surgical manipulation, according to the reports of some authors, varies from 3 to 8 %. The complications of pleural drainage in the patients with acute nonspecific pleural empyema have been studied and the technique of pleural drainage "blindly" has been introduced, which allows drainage to be located along the chest wall. At the first stage of the four−stage study, the complications of pleural drainage in 38 patients with acute nonspecific pleural empyema were analyzed, at the second stage a device for drainage of the pleural cavity "blindly" was developed to place drainage in parallel to the chest wall, at the third stage patients were tested; on IV −− drainage of the pleural cavity of 34 patients was performed according to the proposed method. The reason for the development of drainage complications in the pleural cavity of patients with acute pleural empyema was the inadequate location of drainage in the pleural cavity, drainage of the pleural cavity was carried out in general hospitals without the use of thoracoscopic equipment. Curved thoracoport with trocar for a blind drainage of the pleural cavity "blindly" was developed and introduced into clinical practice. This technique eliminates the involuntary location of the drainage in the pleural cavity, installing it along the chest wall, and is safe. Complications associated with drainage of the pleural cavity according to the developed method using a curved thoracoport with a trocar, inadequate location of drainage, were not observed in patients. Key words: acute pleural empyema, pleural cavity drainage, curved trocar.


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